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Albinism is relatively common in red-tailed hawks.
Red-tailed hawks are considered to be a sign of good luck in the Mescalero Apache tradition (Louie Chavez, personal communication).
Adult red-tailed hawks make what is called a horse scream, "kee-eeee-arrr." It is often described as sounding like a steam whistle. The length and pitch of this call varies with the age, gender, and geographic region of the individual red-tailed hawk.
Young red-tailed hawks communicate with their parents by making soft, low "peep"-ing sounds. As they get older, they sounds they make deepen in tone, and are usually sounds of hunger.
Red-tailed hawks also communicate through body language. In an aggressive posture, the body and head of the red-tailed hawk are held upright and its feathers are standing up. In submission, the hawk's head is lower to the ground and the feathers are smooth. Red-tailed hawks also display many aerial behaviors. In the talon-drop, during courtship, they swoop down trying to touch one another with their talons. Undulating-flight is an up and down movement that is mainly used in territorial display. Finally, in the dive-display the bird performs a steep dive. This is also a territorial display.
Red-tailed hawks have extraordinarily keen vision, which allows them to detect prey movements at great distances.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Red-tailed hawks have extended their geographic range over the last 100 years. This expansion is most likely the result of increasing habitat of patchy woodland and open areas. As these areas become filled in with forest or more completely opened up, the amount of habitat for red-tailed hawks is expected to decline.
Currently, the greatest threats to red-tailed hawk populations are shootings, collisions with automobiles, and human interference with nesting activities. Lead poisoning from eating food items that contain lead shot also kills a number of red-tailed hawks each year.
Red-tailed hawks are protected under the U.S. Migratory Bird Act and CITES Appendix II.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known negative effects of red-tailed hawks on humans.
Red-tailed hawks help farmers by eating mice, moles and other rodents that disturb their crops.
Positive Impacts: controls pest population
Red-tailed hawks play an important role in local ecosystems by helping to control the populations of small mammals, including rodents and rabbits. They also provide habitat for some small bird species, including house sparrows, that live in active red-tailed hawk nests.
Red-tailed hawks have antagonistic relationships with many bird species. Some smaller bird species mob hawks. Red-tailed hawks also steal prey and have prey stolen by other large birds, including golden eagles, bald eagles and ferruginous hawks.
Ecosystem Impact: creates habitat
Commensal/Parasitic Species:
Red-tailed hawks feed on a wide variety of prey, using their powerful claws as weapons. Eighty to eighty-five percent of their diet consists of small rodents. Mammals as large as eastern cottontail rabbits may also taken. Reptiles and other birds make up the rest of the diet. Male red-winged blackbirds are common prey because they are so visible when guarding their nests. Red-tailed hawks do most of their hunting from a perch. They are not known to store food.
Animal Foods: birds; mammals; reptiles
Primary Diet: carnivore (Eats terrestrial vertebrates)
Red-tailed hawks are native only to the Nearctic region. They are found throughout the United States and Canada, and into Mexico and Central America. Many birds are year round occupants although the birds of the far north migrate south during the fall to escape the harsh winter.
Biogeographic Regions: nearctic (Native )
Red-tailed hawks inhabit a wide range of habitats over a wide range of altitudes. These habitats are typically open areas with scattered, elevated perches, and include scrub desert, plains and montane grasslands, agricultural fields, pastures, urban parks, patchy coniferous and deciduous woodlands, and tropical rainforests. Red-tailed hawks prefer to build their nests at the edge of forests, in wooded fence rows, or in large trees surrounded by open areas.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland ; forest ; rainforest ; scrub forest
Other Habitat Features: urban ; suburban ; agricultural ; riparian
Red-tailed hawks are relatively long-lived birds. While many of these birds die young (most live less than two years), those that survive the first few years can live for many years. The oldest known wild red-tailed hawk lived to at least 21.5 years old. In captivity, red-tailed hawks have lived for at least 29.5 years.
Range lifespan
Status: wild: 29.5 (high) years.
Range lifespan
Status: captivity: 29.5 (high) years.
Average lifespan
Status: wild: 346 months.
Red-tailed hawks are 48 to 65 centimeters in length. Their wingspan is approximately 4 feet, or 122 centimeters. Females and males are similar in appearance, but females are 25% larger than males. This kind of sexual dimorphism, where females are larger than males, is common in birds of prey. Mass is reported from 795 to 1224 grams, with mass varying by sex, season, and geographically. Red-tailed hawks range from light auburn to deep brown in color. Their underbelly is lighter than the rest of the body, with a dark band across it. The cere (the soft skin at the base of the beak), the legs and the feet are all yellow. The tail is brownish-red, and it is this trait that gives red-tailed hawks their name.
Immature red-tailed hawks look similar to adults, but... Immatures also have yellowish-gray eyes that become dark brown as adults.
There are at least 14 subspecies of Buteo jamaicensis. These subspecies are separated based differences in their color and differences in where they breed and spend the winter.
Range mass: 795 to 1224 g.
Range length: 45 to 65 cm.
Average wingspan: 122 cm.
Other Physical Features: endothermic ; bilateral symmetry ; polymorphic
Sexual Dimorphism: female larger
Adult red-tailed hawks are large formidable birds, and have few predators. Most predation on this species occurs to eggs and nestlings. Great horned owls are known predators of red-tailed hawk nestlings. Corvids are known predators of eggs and nestlings.
Known Predators:
Red-tailed hawks usually begin breeding when they are three years old. They are monogamous, and mate with the same individual for many years. In fact, red-tailed hawks usually only change mates when their original mate dies. During courtship, the male and female soar together in circles, with flights lasting 10 minutes or more. Mating usually takes place following these flights. The male and female land on a perch and preen each other. The female then tilts forward, allowing the male to mount her. Copulation lasts 5 to 10 seconds.
Mating System: monogamous
Red-tailed hawk nests are usually 28 to 38 inches in diameter. They are sometimes used for several years, and can be up to 3 feet tall. The male and female both construct the nest in a tall tree, 4 to 21 meters above the ground. Where trees are scarce, they are sometimes built on cliff ledges or artificial structures such as on buildings. The nests are constructed of twigs and lined with bark, pine needles, corn cobs, husks, stalks, aspen catkins and other soft plant matter. Fresh bark, twigs, and pine needles are deposited into the nest throughout the breeding season to keep the nest clean. Owls compete with the red-tailed hawks for nest sites. Each species is known to kill the young and destroy the eggs of the other in an attempt at taking a nest site.
The female lays 1 to 5 eggs around the first week of April. The eggs are laid approximately every other day and are incubated for 28 to 35 days. Both parents incubate the eggs. Males may spend less time incubating than females, but bring food to the female while she is on the nest. The young hatch over the course of 2 to 4 days, and are altricial at hatching. During the nestling stage, the female broods the young, and the male provides most of the food to the female and the chicks. The female feeds the nestlings by tearing the food into small pieces. The chicks begin to leave the nest after 42 to 46 days. The fledgling period lasts up to 10 weeks, during which the chicks learn to fly and hunt.
Breeding interval: Red-tailed hawks breed each spring.
Breeding season: Breeding occurs in the spring.
Range eggs per season: 1 to 5.
Range time to hatching: 28 to 35 days.
Average time to hatching: 30 days.
Range fledging age: 42 to 46 days.
Range time to independence: 10 (high) weeks.
Average age at sexual or reproductive maturity (female): 3 years.
Average age at sexual or reproductive maturity (male): 3 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Average eggs per season: 3.
Average age at sexual or reproductive maturity (male)
Sex: male: 730 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 730 days.
Both parents incubate the eggs. Males may spend less time incubating than females, but bring food to the female while she is on the nest. The newly hatched chicks are altricial (helpless). During the nestling stage, the female broods the young, and the male provides most of the food to the female and the chicks. The female feeds the nestlings by tearing the food into small pieces. The chicks begin to leave the nest after 42 to 46 days. After they leave the nest, young red-tailed hawks usually stay in one place, close to their parents. They begin to fly about 3 weeks after they first begin to leave the nest, and begin to catch their own food 6 to 7 weeks after that. They become completely independent from their parents by about 10 weeks after fledging, at about 112 to 116 days old.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
A large (19-25 inches) hawk, the Red-tailed Hawk is most easily identified by its dark brown back, pale underparts, and rusty-red tail visible from above or below. In some parts of this species’ range, exceptionally light or dark subspecies occur, having more or less pigment in the back, breast, and tail than the nominative subspecies. Male and female Red-tailed Hawks are similarly-plumaged in all seasons; however, like most species of raptors, females are larger than males. The Red-tailed Hawk breeds from Alaska and northern Canada south through the United States, the West Indies, Mexico, and parts of Central America. In winter, northerly-breeding populations migrate south to the southern half of the U.S. Southerly-breeding populations migrate short distances, if at all. Red-tailed Hawks are birds of semi-open country. This species inhabits open woodland, shrubby fields, and even urban areas where food is plentiful. Red-tailed Hawks primarily eat small mammals, including lemmings, mice, and voles, but may eat small birds and reptiles when the opportunity presents itself. Red-tailed Hawks are most easily seen soaring over open habitat while scanning the ground for prey, dropping down to capture it with their talons. With the aid of binoculars, it may also be possible to see individual Red-tailed Hawks perching in trees or tall posts near their hunting grounds. This species is primarily active during the day.
A large (19-25 inches) hawk, the Red-tailed Hawk is most easily identified by its dark brown back, pale underparts, and rusty-red tail visible from above or below. In some parts of this species’ range, exceptionally light or dark subspecies occur, having more or less pigment in the back, breast, and tail than the nominative subspecies. Male and female Red-tailed Hawks are similarly-plumaged in all seasons; however, like most species of raptors, females are larger than males. The Red-tailed Hawk breeds from Alaska and northern Canada south through the United States, the West Indies, Mexico, and parts of Central America. In winter, northerly-breeding populations migrate south to the southern half of the U.S. Southerly-breeding populations migrate short distances, if at all. Red-tailed Hawks are birds of semi-open country. This species inhabits open woodland, shrubby fields, and even urban areas where food is plentiful. Red-tailed Hawks primarily eat small mammals, including lemmings, mice, and voles, but may eat small birds and reptiles when the opportunity presents itself. Red-tailed Hawks are most easily seen soaring over open habitat while scanning the ground for prey, dropping down to capture it with their talons. With the aid of binoculars, it may also be possible to see individual Red-tailed Hawks perching in trees or tall posts near their hunting grounds. This species is primarily active during the day.
Distribucion General: Se reproduce desde el oeste de Alaska y el norte de Canadá hasta el oeste de Panamá y las Antillas. Las razas norteñas son migratorias e inviernan regularmente hasta Nicaragua y en ocasiones hasta Panamá.
Buteo jamaicensis, tamién conocíu como gavilán colirrojo o aguililla cola colorada (en Puertu Ricu, guaraguao o warawao), ye una especie d'ave Accipitriforme de la familia Accipitridae, llargamente distribuyida dende Alaska hasta les Antilles. Ye una de les rapazos más abondosos y más utilizaes na cetrería en Norteamérica.
Conócense 14 subespecies de Buteo jamaicensis:[1]
En La Incla, Puertu Ricu, repórtase la mayor densidá d'estes aves en tol mundu.[ensin referencies]
Les variaciones ente les subespecies de Buteo jamaicensis, amás de los distintos híbridos naturales que se producen ente diches subespecies y otros buteos, son considerables, resultando dacuando bien difíciles de clasificar o reconocer pola variación de tamañu y de plumaxe. El plumaxe de xuvenil y adultu ye bien similar pa toles subespecies, anque estos postreros suelen tener les ales más anches y la cola más curtia; les úniques variaciones importantes ente xuveniles y adultos son el color de la cola (nun ye colorada inda) y la banda abdominal, que suel ser más marcada nos mozos que nos adultos d'una mesma subespecie.
Los machos y les femes son similares en cuanto al plumaxe.
El ratoneru de cola colorada recibe'l so nome debíu a los color de la superficie cimera de la so cola, un tonu que va dende un colloráu anaranxáu o inclusive rosa maciu hasta un colloráu intensu, y qu'apaez de normal a partir del añu d'edá o segunda seronda cola primer muda, apreciándose en dellos casos dafechu na segunda muda. Na gran mayoría d'exemplares adultos, a la fin de la so cola apaez una banda ancho y escuro de color negru. La superficie inferior de la so cola ye d'un blancu intensu, qu'en dellos exemplares llega a adquirir un color plateado.
Siendo una de les rapazos más abondosos n'Estaos Xuníos, nun ye d'estrañar que tamién seya una de les rapazos más emplegaes na cetrería, especialmente en Norteamérica y nel Reinu Xuníu, tantu por primerizu como por conocíos maestros cetreros, amás de ser utilizada frecuentemente n'exhibiciones.
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Esta páxina forma parte del wikiproyeutu Aves, un esfuerciu collaborativu col fin d'ameyorar y organizar tolos conteníos rellacionaos con esti tema. Visita la páxina d'alderique del proyeutu pa collaborar y facer entrugues o suxerencies. Buteo jamaicensis, tamién conocíu como gavilán colirrojo o aguililla cola colorada (en Puertu Ricu, guaraguao o warawao), ye una especie d'ave Accipitriforme de la familia Accipitridae, llargamente distribuyida dende Alaska hasta les Antilles. Ye una de les rapazos más abondosos y más utilizaes na cetrería en Norteamérica.
Qızıl quyruqlu şahin[1] — (lat. Buteo jamaicensis, Accipitridae) növündən olan, şimali Amerikada məşhur olan yırtıcı quş növü.
Qərbi Alyaskadan , şimali Kanadaya, cənubda Panamaya və Kariblərə qədər Şimali Amerikanın bir çox bölgəsində törəyər, bu bölgədə ən məşhur olan Buteo növlərindən biridir. Qızıl quyruqlu şahin yaşadığı bölgədə bütün mühitə uyğunlaşa bilir. Görünüşləri və yaşadıqları yerlər ilə bir-birindən ayrılan 14 alt növü qəbul edilmişdir. Boyları 45-50 sm, qanad açıqlıqları 110-145sm və ağırlıqları 690-1600 qr arasında dəyişir. Bu ölçüləri ilə şimali Amerikada yaşayan Buteo cinsi quşların ən böyük növlərindən biridir. Dişi növləri erkək növlərindən daha böyükdür.
Bəzən ayrı növ olaraq qəbul edilən Harlan şahini aşağıda taksonomiya bölməsində göstərilmişdir.
Qızıl quyruqlu şahinlər otlaqlar, meşələr,çöllər və bir çox bölgələr daxil olmaqla bir çox yerlərdə və yüksəklilkərdə yaşaya bilərlər. Arktikanın sıx meşələri xaricində , şimali Amerikanın hər yerində mövcuddurlar.Kanada, Meksika və ABŞ-da qanuni olaraq qoruma altına alınmışdır.
Qızıl quyruqlu şahin Amerika mədəniyyətində vacib bir yerə sahibdir. Tükləri bəzi qəbilələr tərəfindən müqəddəs sayılır və dini mərasimlərdə istifadə edilir.
Erkək quşlar 45-65 sm boyunda və 690-1300 qram ağırlığında ola bilərkən , dişilər 48–65 sm boyunda, 900-2000 qram ağırlığında olurlar.Bir çox yırıtcı quş növlərində olduğu kimi erkək və dişiləri arasında fərqliliklər vardır , erkəklər dişilərdən 25% daha böyükdür.[2]
Qızıl quyruqlu şahinlərin tükləri növlərinə və olduqları bölgələrə görə fərqlilik göstərirlər.Bu fərqlilik tük tökmə ilə əlaqəli deyildir, polimorfizmə bağlıdır. Şimali Amerikanın qərbində olan B.J. calurus növü ən çox dəyişkənlik göstərən növüdür. Üç fərqli rən tipi vardır; açıq ,tünd və pas rəngi. Tünd və pas rəngində olan növləri populyasiyanın 15-20% ni təşkil edir.[3]
Rəng tonları ,izləri fərqli olsa da, ümumilikdə eynidir. Qarınaltı tükləri kürək tüklərindən daha açıq rəngdədir.Qarın hissəsində olan qəhvərəngində bant bütün rəng tiplərində mövcuddur. Dimdikləri, yırtıcı quşlarda olduğu kimi çəngəl şəklindədir və tünd rənglidir. Dimdiyin dibi və ayaqlari sarı rənglidir. Yetişkin olmayan quşlar , yaxın məsafədən sarı rəngli irisləriylə seçilir. Quşlar 3-4 ile yetişkin olmağa başlayarkən , iris tündləşər və qızılı qəhvərəngi bir tona çevrilər.
Qızıl quyruqlu şahin sağlam görünüşlü, geniş qanadlı və orta boylarda , gündüz yırtıcı quşlardan ibarət olan Buteo cinsinin bir növüdür. Bu cinsə aid olan quşlar şahin olaraq bilinir.[4] Görünüşləri və yaşadıqları yerlər ilə bir birindən ayrılan 14 alt qrupu vardır.
Qızıl quyruqlu şahin Amerika qitəsində ən çox yayılmış şahin növlərindən biridir. [7]Şimalda Alyaskanın ortası, Flordia, Karibdə çoxalarlar. Seçdiyi yaşam məkanları yüksək qayalıqlar, ya da yüksək qayalıqlar olan yerlərdir. Arktikanın üst bölgələri və sıx meşələrin xaricində şimali Amerikanın hər yerində mövcuddurlar. Ağac olmayan ara hissələrdə uzun telefon , elektrik dirəkləri olan yolların hazırlanması ovlanmaq üçün məkanlar hazırlamışdır. Qızıl quyruqlu şahinlər şəhərlərdədə yaşamaqdadır.[8]
Qızıl quyruqlu şahin mümkün olduğu qədər enerjisini qorumaq üçün v şəklində açdığı qanadları ilə havada süzülür. Küləyə qarşı qanad çırparaq müəyyən bir nöqtədə dura bilər. Süzülərkən və yaxud qanad çırparkən 32–64 km/s sürətlə uçar.
Qızıl quyruqlu şahin fürsətçidir. Əsas qidası kiçik məməlilərdir , lakin quşları və sürünənləridə yeyə bilər. Ovları mövsümə və bölgəyə görə dəyişər. Ən çox ovladıqları heyvanlar arasında siçan, tarla siçanı , sincab yer alır.[9] Bunların xaricində az da olsa , yarasalar . ilanlar, balıq və böcək də ovladıqları heyvanlar arasındadır. Əsarət altında olan qızıl quşlar gün ərzində 135 qram qida qəbul edər. Qızıl quyruqlu şahin quşları havada tutar , alçaqdan uçaraq yerdə olan heyvanları təqib edərək ovlayar.
Qızıl quyruqlu şahin cinsi yetişkənliyə iki yaşında çatar. Cütlərdən biri ölənə qədər tək əks cinslə cütləşər. Eyni yuva cütlük tərəfindən illərlə qoruna bilər. Cütləşmə zamanı erkək və dişi şahinlər bir birinin ətrafında çığlıqlar ataraq uçuşarlar. Erkək havada akrobatik hərəkətlər edib, yerə enib təkrar yüksələr. Bu hərəkətləri bir müddət sərgilədikdən sonra qısa müddətlik erkək dişinin pəncələrini öz pəncələri ilə tutar. Bundan sonra cütləşərlər. Araşdırmalara görə mart və aprel ayında daha çox yumurta yumurtlayarlar. Yumurtlama iki gündə bir yumurta şəklində olar. Yumurtalar çox vaxt 60x47 mm ölçülərindədir. 28-35 gün sonra 2-4 günlük vaxt içərisində yumurtalar çatlamağa başlayar və bala yumurtadan çıxan kimi bəslənmək məcburiyyətindədilər. Qidanı həm balaya , həm də dişiyə erkək quş gətirir. Dişi quş qidanı kiçik hissələrə ayıraraq balasını bəsləyər. 42-46 gün sonra bala şahinlər kiçik uçuşlar edərək yuvadan ayrılarlar. 10 həftə içərisində balalar ovlamağı və uçmağı öyrənər.
Qızıl quyruqlu şahin — (lat. Buteo jamaicensis, Accipitridae) növündən olan, şimali Amerikada məşhur olan yırtıcı quş növü.
Ar vaou lost rous a zo un evn-preizh, Buteo jamaicensis an anv skiantel anezhañ.
Bevañ a ra al labous e Norzh ha Kreizamerika[1].
Diouzh an evnoniourien e vez renket ar baoued en urzhiad Falconiformes pe Accipitriformes.
Ar vaou lost rous a zo un evn-preizh, Buteo jamaicensis an anv skiantel anezhañ.
L'aligot cua-roig o aligot de cua roja[1] (Buteo jamaicensis) és un ocell de la família dels accipítrids (Accipitridae) que habita boscos i zones obertes d'Amèrica del Nord, des d'Alaska central i oriental, a l'ample de Canadà, Estats Units i Mèxic, incloent les illes Marías i Revillagigedo, a través d'Amèrica Central fins a Panamà, i també a les Bahames, i les Antilles. Les poblacions d'Alaska i Canadà passen l'hivern en Amèrica Central i les Antilles.
L'aligot cua-roig o aligot de cua roja (Buteo jamaicensis) és un ocell de la família dels accipítrids (Accipitridae) que habita boscos i zones obertes d'Amèrica del Nord, des d'Alaska central i oriental, a l'ample de Canadà, Estats Units i Mèxic, incloent les illes Marías i Revillagigedo, a través d'Amèrica Central fins a Panamà, i també a les Bahames, i les Antilles. Les poblacions d'Alaska i Canadà passen l'hivern en Amèrica Central i les Antilles.
Aderyn a rhywogaeth o adar yw Bwncath cynffongoch y Gogledd (sy'n enw gwrywaidd; enw lluosog: bwncathod cynffongoch y Gogledd) a adnabyddir hefyd gyda'i enw gwyddonol Buteo jamaicensis; yr enw Saesneg arno yw Red-tailed hawk. Mae'n perthyn i deulu'r Eryr (Lladin: Accipitridae) sydd yn urdd y Falconiformes.[1]
Talfyrir yr enw Lladin yn aml yn B. jamaicensis, sef enw'r rhywogaeth.[2] Mae'r rhywogaeth hon i'w chanfod yng Ngogledd America.
Caiff yr aderyn hwn ei ddefnyddio ar gyfer heboca.
Mae'r bwncath cynffongoch y Gogledd yn perthyn i deulu'r Eryr (Lladin: Accipitridae). Dyma rai o aelodau eraill y teulu:
Rhestr Wicidata:
rhywogaeth enw tacson delwedd Aquila spilogaster Aquila spilogaster Aquila wahlbergi Aquila wahlbergi
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Aderyn a rhywogaeth o adar yw Bwncath cynffongoch y Gogledd (sy'n enw gwrywaidd; enw lluosog: bwncathod cynffongoch y Gogledd) a adnabyddir hefyd gyda'i enw gwyddonol Buteo jamaicensis; yr enw Saesneg arno yw Red-tailed hawk. Mae'n perthyn i deulu'r Eryr (Lladin: Accipitridae) sydd yn urdd y Falconiformes.
Talfyrir yr enw Lladin yn aml yn B. jamaicensis, sef enw'r rhywogaeth. Mae'r rhywogaeth hon i'w chanfod yng Ngogledd America.
Caiff yr aderyn hwn ei ddefnyddio ar gyfer heboca.
Káně rudoocasá (Buteo jamaicensis) je středně velký dravý pták z čeledi jestřábovitých. Hnízdí téměř na celém území Severní Ameriky v rozmezí od západní Aljašky a severní Kanady až po Panamu a Karibik a náleží vůbec mezi nejhojnější severoamerická káňata. Vyskytuje se ve 14 poddruzích, které se mezi sebou liší zbarvením a areálem rozšíření.
Káně rudoocasá dorůstá 45 – 65 cm a v rozpětí křídel měří 110 – 145 cm, samice přitom bývají průměrně asi o 25% větší než samci. Hmotnost u dospělých jedinců se obvykle pohybuje mezi 690–1600 g. Svrchu je hnědá, spodinu má světlejší s výraznými hnědými stříkanci a ocas charakteristicky cihlově zbarvený.
Obývá širokou paletu lokalit v různých nadmořských výškách, včetně pouští, pastvin, jehličnatých, opadavých i tropických deštných lesů, zemědělské půdy a městských oblastí. V Kanadě, Mexiku a Spojených státech je chráněná.
Požírá zejména malé savce, ale také ptáky, plazy a vzácněji i netopýry, hady, ryby, korýše a hmyz. Složení její potravy se mění podle oblastí a ročního období, až 85 % z její potravy však obvykle zabírají hlodavci. Je monogamní. Klade 2 - 3 vejce, na kterých sedí po dobu 28 - 35 dnů.
Díky její zatím stále poměrně vysoké početnosti a snadnému výcviku se často využívá i v sokolnictví. Má také význam u některých původních severoamerických kmenů, kteří její pera považovaly za posvátné a využívaly je při náboženských obřadech.
V tomto článku byl použit překlad textu z článku Red-tailed Hawk na anglické Wikipedii.
Obrázky, zvuky či videa k tématu káně rudoocasá ve Wikimedia Commons
Galerie káně rudoocasá ve Wikimedia CommonsKáně rudoocasá (Buteo jamaicensis) je středně velký dravý pták z čeledi jestřábovitých. Hnízdí téměř na celém území Severní Ameriky v rozmezí od západní Aljašky a severní Kanady až po Panamu a Karibik a náleží vůbec mezi nejhojnější severoamerická káňata. Vyskytuje se ve 14 poddruzích, které se mezi sebou liší zbarvením a areálem rozšíření.
Káně rudoocasá dorůstá 45 – 65 cm a v rozpětí křídel měří 110 – 145 cm, samice přitom bývají průměrně asi o 25% větší než samci. Hmotnost u dospělých jedinců se obvykle pohybuje mezi 690–1600 g. Svrchu je hnědá, spodinu má světlejší s výraznými hnědými stříkanci a ocas charakteristicky cihlově zbarvený.
Obývá širokou paletu lokalit v různých nadmořských výškách, včetně pouští, pastvin, jehličnatých, opadavých i tropických deštných lesů, zemědělské půdy a městských oblastí. V Kanadě, Mexiku a Spojených státech je chráněná.
Požírá zejména malé savce, ale také ptáky, plazy a vzácněji i netopýry, hady, ryby, korýše a hmyz. Složení její potravy se mění podle oblastí a ročního období, až 85 % z její potravy však obvykle zabírají hlodavci. Je monogamní. Klade 2 - 3 vejce, na kterých sedí po dobu 28 - 35 dnů.
Díky její zatím stále poměrně vysoké početnosti a snadnému výcviku se často využívá i v sokolnictví. Má také význam u některých původních severoamerických kmenů, kteří její pera považovaly za posvátné a využívaly je při náboženských obřadech.
Der Rotschwanzbussard (Buteo jamaicensis) ist ein Vogelart aus der Gattung der Echten Bussarde (Buteo) in der Familie der Habichtartigen (Accipitridae). Er ist der häufigste Bussard in Nordamerika und ernährt sich von Nagern.
Der Rotschwanzbussard hat eine Körperlänge von 45 bis 58 Zentimetern und eine Spannweite von 107 bis 141 Zentimetern. Männchen sind kleiner als Weibchen. Er hat breite, abgerundete Flügel und einen deutlich kräftigeren Schnabel als der Raufußbussard. Das Gefieder ist sehr variabel; im Gesamtverbreitungsgebiet werden zehn Unterarten unterschieden, die zum Teil jeweils auch noch mehrere Farbmorphen ausbilden.
Bei ausgewachsenen Vögeln ist die Grundfarbe der Oberseite des Rumpfes und der Flügel dunkelbraun; bei dunklen Morphen einfarbig, bei hellen Morphen mit weißlichen Flecken durchsetzt. Diese helle Fleckung kann auf den Flügeln und im Bereich des mittleren Rückens besonders deutlich ausgeprägt sein und so deutliche, helle Bänder bilden. Der Schwanz ist ungebändert und bei den beiden Unterarten mit dem größten Verbreitungsgebiet (B. j. borealis und B. j. calurus) oberseits meist rostrot, unterseits blassrot mit einer schwachen dunklen Subterminalbinde und einer schmalen weißlichen Endbinde.
Rumpfunterseite und Unterflügeldecken sind bei helleren Morphen weißlich. Der Flügelbug ist vom Flügelansatz etwa bis zum Carpalgelenk dunkel, außerdem zeigt der Bauch meist ein Band aus dunklen Längsflecken. Bei dunkleren Morphen ist der Rumpf wie die Oberseite einfarbig braun oder rötlich. Die Iris ist dunkelbraun bis rötlich.
Bei Jungvögeln ist der Schwanz im Gegensatz zu den Altvögeln graubraun mit durchgehenden, zahlreichen dunklen Querbinden, einer breiteren Subterminalbinde und einer weißlichen Endbinde, außer bei der Unterart Buteo j. harlani. Die Unterseite ist dunkel gefleckt, die Iris hell.
Der charakteristische Ruf ist ein raues, absteigendes „kiiieer“. Der schrille Schrei wird in populären Medien wie z. B. Spielfilmen regelmäßig als „Standardschrei“ für verschiedenste Arten Greifvögel (wie z. B. Weißkopfseeadler) und Falken genutzt, deren Originalrufe oft weniger eindrucksvoll sind.[1]
Wälder mit angrenzenden offenen Flächen, Prärie mit Gehölzen, auch Wüsten.
Der Rotschwanzbussard (Buteo jamaicensis) ist ein Vogelart aus der Gattung der Echten Bussarde (Buteo) in der Familie der Habichtartigen (Accipitridae). Er ist der häufigste Bussard in Nordamerika und ernährt sich von Nagern.
The red-tailed hawk (Buteo jamaicensis) is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members within the genus of Buteo in North America or worldwide.[2] The red-tailed hawk is one of three species colloquially known in the United States as the "chickenhawk", though it rarely preys on standard-sized chickens.[3] The bird is sometimes also referred to as the red-tail for short, when the meaning is clear in context. Red-tailed hawks can acclimate to all the biomes within their range, occurring on the edges of non-ideal habitats such as dense forests and sandy deserts.[4] The red-tailed hawk occupies a wide range of habitats and altitudes, including deserts, grasslands (from small meadows to the treed fringes of more extensive prairies), coniferous and deciduous forests, agricultural fields, and urban areas. Its latitudinal limits fall around the tree line in the subarctic and it is absent from the high Arctic. Generally it favors varied habitats with open woodland, woodland edge and open terrain. It is legally protected in Canada, Mexico, and the United States by the Migratory Bird Treaty Act.
The 14 recognized subspecies vary in appearance and range, varying most often in color, and in the west of North America, red-tails are particularly often strongly polymorphic, with individuals ranging from almost white to nearly all black.[5] The subspecies Harlan's hawk (B. j. harlani) is sometimes considered a separate species (B. harlani).[6] The red-tailed hawk is one of the largest members of the genus Buteo, typically weighing from 690 to 1,600 g (1.5 to 3.5 lb) and measuring 45–65 cm (18–26 in) in length, with a wingspan from 110–141 cm (3 ft 7 in – 4 ft 8 in). This species displays sexual dimorphism in size, with females averaging about 25% heavier than males.[2][7]
The diet of red-tailed hawks is highly variable and reflects their status as opportunistic generalists, but in North America, they are most often predators of small mammals such as rodents of an immense diversity of families and species. Prey that is terrestrial and at least partially diurnal is preferred, so types such as ground squirrels are preferred where they naturally occur.[8] Over much of the range, smallish rodents such as voles alternated with larger rabbits and hares often collectively form the bulk of the diet. Large numbers of birds and reptiles can occur in the diet in several areas, and can even be the primary foods. Meanwhile, amphibians, fish and invertebrates can seem rare in the hawk’s regular diet, but they are not infrequently taken by immature hawks. Red-tailed hawks may survive on islands absent of native mammals on diets variously including invertebrates such as crabs, as well as lizards or birds. Like many Buteo species, they hunt from a perch most often, but can vary their hunting techniques where prey and habitat demand it.[5][9] Because they are so common and easily trained as capable hunters, in the United States they are the most commonly captured hawks for falconry. Falconers are permitted to take only passage hawks (which have left the nest, are on their own, but are less than a year old) so as to not affect the breeding population. Passage red-tailed hawks are also preferred by falconers because they have not yet developed the adult behaviors that would make them more difficult to train.[10]
The red-tailed hawk was formally described in 1788 by German naturalist Johann Friedrich Gmelin under the binomial name Falco jamaicensis.[11] Gmelin based his description on the "cream-coloured buzzard" described in 1781 by John Latham in his A General Synopsis of Birds.[12] The type locality is Jamaica.[13] The red-tailed hawk is now placed in the genus Buteo that was erected by French naturalist Bernard Germain de Lacépède in 1799.[14][15]
The red-tailed hawk is a member of the subfamily Buteoninae, which includes about 55 currently recognized species.[2][16] Unlike many lineages of accipitrids, which seemed to have radiated out of Africa or south Asia, the Buteoninae clearly originated in the Americas based on fossil records and current species distributions (more than 75% of the extant hawks from this lineage are found in the Americas).[2][17] As a subfamily, the Buteoninae seem to be rather old based on genetic materials, with monophyletic genera bearing several million years of individual evolution. Diverse in plumage appearance, habitat, prey, and nesting preferences, buteonine hawks are nonetheless typically medium- to large-sized hawks with ample wings (while some fossil forms are very large, larger than any eagle alive today).[18][19][20] The red-tailed hawk is a member of the genus Buteo, a group of medium-sized raptors with robust bodies and broad wings. Members of this genus are known as "buzzards" in Eurasia, but "hawks" in North America.[21] Under current classification, the genus includes about 29 species, the second-most diverse of all extant accipitrid genera behind only Accipiter.[15] The buzzards of Eurasia and Africa are mostly part of the genus Buteo, although two other small genera within the subfamily Buteoninae occur in Africa.[2][16][22]
At one time, the rufous-tailed hawk (B. ventralis), distributed in Patagonia and some other areas of southern South America, was considered part of the red-tailed hawk species. With a massive distributional gap consisting of most of South America, the rufous-tailed hawk is considered a separate species now, but the two hawks still compromise a "species pair" or superspecies, as they are clearly closely related. The rufous-tailed hawk, while comparatively little studied, is very similar to the red-tailed hawk, being about the same size and possessing the same wing structure, and having more or less parallel nesting and hunting habits. Physically, however, rufous-tailed hawk adults do not attain a bright brick-red tail as do red-tailed hawks, instead retaining a dark brownish-cinnamon tail with many blackish crossbars similar to juvenile red-tailed hawks.[2][23][24] Another, more well-known, close relative to the red-tailed hawk is the common buzzard (B. buteo), which has been considered as its Eurasian "broad ecological counterpart" and may also be within a species complex with red-tailed hawks. The common buzzard, in turn, is also part of a species complex with other Old World buzzards, namely the mountain buzzard (B. oreophilus), the forest buzzard (B. trizonatus ), and the Madagascar buzzard (B. brachypterus).[2][22][25] All six species, although varying notably in size and plumage characteristics, in the alleged species complex that contains the red-tailed hawk share with it the feature of the blackish patagium marking, which is missing in most other Buteo spp.[2][26]
At least 14 recognized subspecies of B. jamaicensis are described, which vary in range and in coloration. Not all authors accept every subspecies, though, particularly some of the insular races of the tropics (which differ only slightly in some cases from the nearest mainland forms) and particularly Krider's hawk, by far the most controversial red-tailed hawk race, as few authors agree on its suitability as a full-fledged subspecies.[5][9][27]
Red-tailed hawk plumage can be variable, depending on the subspecies and the region. These color variations are morphs, and are not related to molting. The western North American population, B. j. calurus, is the most variable subspecies and has three main color morphs: light, dark, and intermediate or rufous. The dark and intermediate morphs constitute 10–20% of the population in the Western United States, but seem to constitute only 1–2% of B. j. calurus in western Canada.[28][29] A whitish underbelly with a dark brown band across the belly, formed by horizontal streaks in feather patterning, is present in most color variations. This feature is variable in eastern hawks and generally absent in some light subspecies (i.e. B. j. fuertesi).[2] Most adult red-tails have a dark-brown nape and upper head, which gives them a somewhat hooded appearance, while the throat can variably present a lighter brown "necklace". Especially in younger birds, the underside may be otherwise covered with dark-brown spotting, and some adults may too manifest this stippling. The back is usually a slightly darker brown than elsewhere with paler scapular feathers, ranging from tawny to white, forming a variable imperfect "V" on the back. The tail of most adults, which gives this species its name, is rufous brick-red above with a variably sized, black subterminal band and generally appears light buff-orange from below. In comparison, the typical pale immatures (i.e. less than two years old) typically have a mildly paler headed and tend to show a darker back than adults with more apparent pale wing-feather edges above (for descriptions of dark morph juveniles from B. j. calurus, which is also generally apt for description of rare dark morphs of other races, see under that subspecies description). In immature red-tailed hawks of all morphs, the tail is a light brown above with numerous small dark brown bars of roughly equal width, but these tend to be much broader on dark morph birds. Even in young red-tails, the tail may be a somewhat rufous tinge of brown.[2][4][30] The bill is relatively short and dark, in the hooked shape characteristic of raptors, and the head can sometimes appear small in size against the thick body frame.[2] The cere, the legs, and the feet of the red-tailed hawk are all yellow, as is the color of bare parts in many accipitrids of different lineages.[31] Immature birds can be readily identified at close range by their yellowish irises. As the bird attains full maturity over the course of 3–4 years, the iris slowly darkens into a reddish-brown, which is the adult eye-color in all races.[4][30] Seen in flight, adults usually have dark brown along the lower edge of the wings, against a mostly pale wing, which bares light brownish barring. Individually, the underwing coverts can range from all dark to off-whitish (most often more heavily streaked with brown) which contrasts with a distinctive black patagium marking. The wing coloring of adults and immatures is similar but for typical pale morph immatures having somewhat heavier brownish markings.[2][27]
Though the markings and color vary across the subspecies, the basic appearance of the red-tailed hawk is relatively consistent.
Overall, this species is blocky and broad in shape, often appearing (and being) heavier than other Buteos of similar length. They are the heaviest Buteos on average in eastern North America, albeit scarcely ahead of the larger winged rough-legged buzzard (Buteo lagopus), and second only in size in the west to the ferruginous hawk (Buteo regalis). Red-tailed hawks may be anywhere from the fifth to the ninth heaviest Buteo in the world depending on what figures are used. However, in the northwestern United States, ferruginous hawk females are 35% heavier than female red-tails from the same area.[2] On average, western red-tailed hawks are relatively longer winged and lankier proportioned but are slightly less stocky, compact and heavy than eastern red-tailed hawks in North America. Eastern hawks may also have mildly larger talons and bills than western ones. Based on comparisons of morphology and function amongst all accipitrids, these features imply that western red-tails may need to vary their hunting more frequently to on the wing as the habitat diversifies to more open situations and presumably would hunt more variable and faster prey, whereas the birds of the east, which was historically well-wooded, are more dedicated perch hunters and can take somewhat larger prey but are likely more dedicated mammal hunters.[9][32][33] In terms of size variation, red-tailed hawks run almost contrary to Bergmann's rule (i.e. that northern animals should be larger in relation than those closer to the Equator within a species) as one of the northernmost subspecies, B. j. alascensis, is the second smallest race based on linear dimensions and that two of the most southerly occurring races in the United States, B. j. fuertesi and B. j. umbrinus, respectively, are the largest proportioned of all red-tailed hawks.[9][33][34] Red-tailed hawks tend have a relatively short but broad tails and thick, chunky wings.[30] Although often described as long-winged,[2][4] the proportional size of the wings is quite small and red-tails have high wing loading for a buteonine hawk. For comparison, two other widespread Buteo hawks in North America were found to weigh: 30 g (1.1 oz) for every square centimeter of wing area in the rough-legged buzzard (B. lagopus) and 44 g (1.6 oz)/cm2 in the red-shouldered hawk (B. lineatus). In contrast, the red-tailed hawk weighed considerably more for their wing area: 199 g (7.0 oz) per square cm.[35]
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As is the case with many raptors, the red-tailed hawk displays sexual dimorphism in size, as females are on average 25% larger than males.[31] As is typical in large raptors, frequently reported mean body mass for red-tailed hawks is somewhat higher than expansive research reveals.[36] Part of this weight variation is seasonal fluctuations; hawks tend to be heavier in winter than during migration or especially during the trying summer breeding season, and also due to clinal variation. Furthermore, immature hawks are usually lighter in mass than their adult counterparts despite having somewhat longer wings and tails. Male red-tailed hawks may weigh from 690 to 1,300 g (1.52 to 2.87 lb) and females may weigh 801 to 1,723 g (1.766 to 3.799 lb) (the lowest figure from a migrating female immature from Goshute Mountains, Nevada, the highest from a wintering female in Wisconsin).[5][16][37] Some sources claim the largest females can weigh up to 2,000 g (4.4 lb), but whether this is in reference to wild hawks (as opposed to those in captivity or used for falconry) is not clear.[38] The largest known survey of body mass in red-tailed hawks is still credited to Craighead and Craighead (1956), who found 100 males to average 1,028 g (2.266 lb) and 108 females to average 1,244 g (2.743 lb). However, these figures were apparently taken from labels on museum specimens, from natural history collections in Wisconsin and Pennsylvania, without note to the region, age, or subspecies of the specimens.[5][39] However, 16 sources ranging in sample size from the aforementioned 208 specimens to only four hawks in Puerto Rico (with 9 of the 16 studies of migrating red-tails), showed that males weigh a mean of 860.2 g (1.896 lb) and females weigh a mean of 1,036.2 g (2.284 lb), about 15% lighter than prior species-wide published weights. Within the continental United States, typical weights of males can range from 840.8 g (1.854 lb) (for migrating males in Chelan County, Washington) to 1,031 g (2.273 lb) (for male hawks found dead in Massachusetts), and females ranged from 1,057.9 g (2.332 lb) (migrants in the Goshutes) to 1,373 g (3.027 lb) (for females diagnosed as B. j. borealis in western Kansas).[36][9][32][40][41][42][43][44] Size variation in body mass reveals that the red-tailed hawk typically varies only a modest amount and that size differences are geographically inconsistent.[9][40]
Male red-tailed hawks can measure 45 to 60 cm (18 to 24 in) in total length, females measuring 48 to 65 cm (19 to 26 in) long. Their wingspan typically can range from 105 to 141 cm (3 ft 5 in to 4 ft 8 in), although the largest females may possible span up to 147 cm (4 ft 10 in). In the standard scientific method of measuring wing size, the wing chord is 325.1–444.5 mm (12.80–17.50 in) long. The tail measures 188 to 258.7 mm (7.40 to 10.19 in) in length.[2][16][45] The exposed culmen was reported to range from 21.7 to 30.2 mm (0.85 to 1.19 in) and the tarsus averaged 74.7–95.8 mm (2.94–3.77 in) across the races.[36][9][46] The middle toe (excluding talon) can range from 38.3 to 53.8 mm (1.51 to 2.12 in), with the hallux-claw (the talon of the rear toe, which has evolved to be the largest in accipitrids) measuring from 24.1 to 33.6 mm (0.95 to 1.32 in) in length.[36][9]
Although they overlap in range with most other American diurnal raptors, identifying most mature red-tailed hawks to species is relatively straightforward, particularly if viewing a typical adult at a reasonable distance. The red-tailed hawk is the only North American hawk with a rufous tail and a blackish patagium marking on the leading edge of its wing (which is obscured only on dark morph adults and Harlan’s hawks by similarly dark-colored feathers).[2] Other larger adult Buteo spp. in North America usually have obvious distinct markings that are absent in red-tails, whether the rufous-brown "beard" of Swainson's hawks (B. swainsonii) or the colorful rufous belly and shoulder markings and striking black-and-white mantle of red-shouldered hawks (also the small "windows" seen at the end of their primaries).[47] In perched individuals, even as silhouettes, the shape of large Buteo spp. may be distinctive, such as the wingtips overhanging the tail in several other species, but not in red-tails. North American Buteo spp. range from the dainty, compact builds of much smaller ones, such as broad-winged hawk (B. platypterus) to the heavyset, neckless look of ferruginous hawks or the rough-legged buzzards, which have a compact, smaller appearance than a red-tail in perched birds due to its small bill, short neck, and much shorter tarsi, while the opposite effect occurs in flying rough-legs with their much bigger wing area.[2][47] In flight, most other large North American Buteo spp. are distinctly longer and more slender-winged than red-tailed hawks, with the much paler ferruginous hawk having peculiarly slender wings in relation to its massive, chunky body. Swainson's hawks are distinctly darker on the wing and ferruginous hawks are much paler-winged than typical red-tailed hawks. Pale morph adult ferruginous hawk can show mildly tawny-pink (but never truly rufous) upper tail, and like red-tails tend to have dark markings on underwing-coverts and can have a dark belly band, but compared to red-tailed hawks have a distinctly broader head, their remiges are much whiter looking with very small, dark primary tips, they lack the red-tail's diagnostic patagial marks and usually also lack the dark subterminal tail-band, and ferruginous hawks have totally feathered tarsi. With its whitish head, the ferruginous hawk is most similar to Krider's red-tailed hawks, especially in immature plumage, but the larger hawk has broader head and narrower wing shape, and the ferruginous immatures are paler underneath and on their legs. Several species share a belly band with the typical red-tailed hawk, but they vary from subtle (as in the ferruginous hawk) to solid blackish, the latter in most light-morph rough-legged buzzards.[2][27] More difficult to identify among adult red-tails are their darkest variations, as most species of Buteo in North America also have dark morphs. Western dark morph red-tails (i.e. B. j. calurus) adults, however, retain the typical distinctive brick-red tail, which other species lack, and may stand out even more against the otherwise all chocolate-brown to black bird. Standard pale juveniles when perched show a whitish patch in the outer half of the upper surface of the wing, which other juvenile Buteo spp. lack.[4] The most difficult to identify stages and plumage types are dark morph juveniles, Harlan's hawk and some Krider's hawks (the latter mainly with typical ferruginous hawks as mentioned). Some darker juveniles are similar enough to other Buteo juveniles that they "cannot be identified to species with any confidence under various field conditions."[5][4] However, field identification techniques have advanced in the last few decades and most experienced hawk-watchers can distinguish even the most vexingly plumaged immature hawks, especially as the wing shapes of each species becomes apparent after seeing many. Harlan’s hawks are most similar to dark morph rough-legged buzzards and dark morph ferruginous hawks. Wing shape is the most reliable identification tool for distinguishing Harlan's hawks from these, but also the pale streaking on the breast of Harlan's, which tends to be conspicuous in most individuals, and is lacking in the other hawks. Also, dark morph ferruginous hawks do not have the dark subterminal band of a Harlan's hawk, but do bear a black undertail covert lacking in Harlan's.[2][48]
The cry of the red-tailed hawk is a 2- to 3-second, hoarse, rasping scream, variously transcribed as kree-eee-ar, tsee-eeee-arrr or sheeeeee,[49] that begins at a high pitch and slurs downward.[2][27][50] This cry is often described as sounding similar to a steam whistle.[31][27] The red-tailed hawk frequently vocalizes while hunting or soaring, but vocalizes loudest and most persistently in defiance or anger, in response to a predator or a rival hawk's intrusion into its territory.[27][49] At close range, it makes a croaking guh-runk, possibly as a warning sound.[51] Nestlings may give peeping notes with a "soft, sleepy quality" that give way to occasional screams as they develop, but those are more likely to be a soft whistle rather than the harsh screams of the adults. Their latter hunger call, given from 11 days (as recorded in Alaska) to after fledgling (in California), is different, a two-syllabled, wailing klee-uk food cry exerted by the young when parents leave the nest or enter their field of vision.[5][52] A strange mechanical sound "not very unlike the rush of distant water" has been reported as uttered in the midst of a sky-dance.[5] A modified call of chirp-chwirk is given during courtship, while a low key, duck-like nasal gank may be given by pairs when they are relaxed.[27]
The fierce, screaming cry of the adult red-tailed hawk is frequently used as a generic raptor sound effect in television shows and other media, even if the bird featured is not a red-tailed hawk.[53][54] It is especially used in depictions of the bald eagle, which contributes to the common misconception that it is a bald eagle cry; actual bald eagle vocalizations are far softer and more chirpy than those of a red-tailed hawk.[55]
The red-tailed hawk is one of the most widely distributed of all raptors in the Americas. It occupies the largest breeding range of any diurnal raptor north of the Mexican border, just ahead of the American kestrel (Falco sparverius). While the peregrine falcon (Falco peregrinus) has a greater latitudinal distribution as a nester in North America, its range as a breeding species is far more sporadic and sparse than that of red-tailed hawks.[56] The red-tailed hawk breeds from nearly north-central Alaska, the Yukon, and a considerable portion of the Northwest Territories, there reaching as far as a breeder as Inuvik, Mackenzie River Delta and skirting the southern shores of Great Bear Lake and Great Slave Lake. Thereafter in northern Canada, breeding red-tails continue to northern Saskatchewan and across to north-central Ontario east to central Quebec and the Maritime Provinces of Canada, and south continuously to Florida. No substantial gaps occur throughout the entire contiguous United States, where breeding red-tailed hawks do not occur. Along the Pacific, their range includes all of Baja California, including Islas Marías, and Socorro Island in the Revillagigedo Islands. On the mainland, breeding red-tails are found continuously to Oaxaca, then experience a brief gap at the Isthmus of Tehuantepec thereafter subsequently continuing from Chiapas through central Guatemala on to northern Nicaragua. To the south, the population in highlands from Costa Rica to central Panama is isolated from breeding birds in Nicaragua. Further east, breeding red-tailed hawks occur in the West Indies in north Bahamas (i.e. Grand Bahama, Abaco and Andros) and all larger islands (such as Cuba, Jamaica, Hispaniola, and Puerto Rico) and into the northern Lesser Antilles (Virgin Islands, Saint Barthélemy, Saba, Saint Kitts, and Nevis, being rare as a resident on Saint Eustatius and are probably extinct on Saint Martin). Their typical winter range stretches from southern Canada south throughout the remainder of the breeding range.[2][57][56]
Red-tailed hawks have shown the ability to become habituated to almost any habitat present in North and Central America. Their preferred habitat is mixed forest and field, largely woodland edge with tall trees or alternately high bluffs that may be used as nesting and perching sites. They occupy a wide range of habitats and altitudes, including deserts, grasslands, nearly any coastal or wetland habitat, mountains, foothills, coniferous and deciduous woodlands, and tropical rainforests. Agricultural fields and pastures, which are more often than not varied with groves, ridges, or streamside trees in most parts of America, may make nearly ideal habitat for breeding or wintering red-tails. They also adapt well to suburban areas especially ones with tall trees or any kind of parkland.[1][5][9][27] Some red-tails may survive or even flourish in urban areas, usually hunting and roosting in available urban parks, cemeteries, road verges, and so on, and nesting freely either in trees or virtually any tall man-made structures.[49][58] One famous urban red-tailed hawk, known as "Pale Male", became the subject of a nonfiction book, Red-Tails in Love: A Wildlife Drama in Central Park, and is the first known red-tail in decades to successfully nest and raise young in the crowded New York City borough of Manhattan.[59][60][61][62] As studied in Syracuse, New York, the highway system has been very beneficial to red-tails as it juxtaposed trees and open areas and blocks human encroachment with fences, with the red-tailed hawks easily becoming acclimated to car traffic. The only practice that has a negative effect on the highway-occupying red-tails is the planting of exotic Phragmites, which may occasionally obscure otherwise ideal highway habitat.[63]
In the northern Great Plains, the widespread practices of wildfire suppression and planting of exotic trees by humans has allowed groves of aspen and various other trees to invade what was once vast, almost continuous prairie grasslands, causing grassland obligates such as ferruginous hawks to decline and allowing parkland-favoring red-tails to flourish.[5][64] To the contrary, clear-cutting of mature woodlands in New England, resulting in only fragmented and isolated stands of trees or low second growth remaining, was recorded to also benefit red-tailed hawks, despite being to the determent of breeding red-shouldered hawks.[65] The red-tailed hawk, as a whole, rivals the peregrine falcon and the great horned owl among raptorial birds in the use of diverse habitats in North America.[5][66] Beyond the high Arctic (as they discontinue as a breeder at the tree line), few other areas exist where red-tailed hawks are absent or rare in North and Central America. Some areas of unbroken forest, especially lowland tropical forests, rarely host red-tailed hawks, although they can occupy forested tropical highlands surprisingly well. In deserts, they can only occur where some variety of arborescent growth or ample rocky bluffs or canyons occur.[28][67][68]
The red-tailed hawk is highly conspicuous to humans in much of its daily behavior. Most birds in resident populations, which are well more than half of all red-tailed hawks, usually split nonbreeding-season activity between territorial soaring flight and sitting on a perch. Often, perching is for hunting purposes, but many sit on a tree branch for hours, occasionally stretching on a single wing or leg to keep limber, with no signs of hunting intent.[5][4][65] Wintering typical pale-morph hawks in Arkansas were found to perch in open areas near the top of tall, isolated trees, whereas dark morphs more frequently perched in dense groups of trees.[4] For many, and perhaps most, red-tailed hawks being mobbed by various birds is a daily concern and can effectively disrupt many of their daily behaviors. Mostly larger passerines, of multiple families from tyrant flycatchers to icterids, mob red-tails, despite other raptors, such as Accipiter hawks and falcons, being a notably greater danger to them.[69][70] The most aggressive and dangerous attacker as such is likely to be various crows or other corvids, i.e. American crows (Corvus brachyrhynchos), because a mobbing group (or "murder") of them can number up to as many as 75 crows, which may cause grievous physical harm to a solitary hawk, and if the hawks are nesting, separate the parent hawks and endanger the eggs or nestlings within their nest to predation by crows.[71][72] Birds that mob red-tailed hawks can tell how distended the hawk's crop is (i.e. the upper chest and throat area being puffy versus flat-feathered and sleek), thus mob more often when the hawk is presumably about to hunt.[73]
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In flight, this hawk soars with wings often in a slight dihedral, flapping as little as possible to conserve energy. Soaring is by far the most efficient method of flight for red-tailed hawks, so is used more often than not.[74] Active flight is slow and deliberate, with deep wing beats. Wing beats are somewhat less rapid in active flight than in most other Buteo hawks, even heavier species such as ferruginous hawks tend to flap more swiftly, due to the morphology of the wings.[75] In wind, it occasionally hovers on beating wings and remains stationary above the ground, but this flight method is rarely employed by this species.[9][28] When soaring or flapping its wings, it typically travels from 32 to 64 km/h (20 to 40 mph), but when diving may exceed 190 km/h (120 mph).[50] Although North American red-tailed hawks will occasionally hunt from flight, a great majority of flight by red-tails in this area is for non-hunting purpose.[74] During nest defense, red-tailed hawks may be capable of surprisingly swift, vigorous flight, while repeatedly diving at perceived threats.[76]
Red-tailed hawks are considered partial migrants, as in about the northern third of their distribution, which is most of their range in Canada and Alaska, they almost entirely vacate their breeding grounds.[2][9] In coastal areas of the north, however, such as in the Pacific Northwest to southern Alaska and in Nova Scotia on the Atlantic, red-tailed hawks do not usually migrate.[5] More or less, any area where snow cover is nearly continuous during the winter shows an extended absence of most red-tailed hawks, so some areas as far south as Montana may show strong seasonal vacancies of red-tails.[5] In southern Michigan, immature red-tailed hawks tended to remain in winter only when voles were abundant. During relatively long, harsh winters in Michigan, many more young ones were reported in northeastern Mexico.[5][39] To the opposite extreme, hawks residing as far north as Fairbanks, Alaska, may persevere through the winter on their home territory, as was recorded with one male over three consecutive years.[77] Birds of any age tend to be territorial during winter but may shift ranges whenever food requirements demand it.[5] Wintering birds tend to perch on inconspicuous tree perches, seeking shelter especially if they have a full crop or are in the midst of poor or overly windy weather. Adult wintering red-tails tend to perch more prominently than immatures do, which select lower or more secluded perches. Immatures are often missed in winter bird counts, unless they are being displaced by dominant adults. Generally, though, immatures can seem to recognize that they are less likely to be attacked by adults during winter and can perch surprisingly close to them. Age is the most significant consideration of wintering hawks' hierarchy, but size does factor in, as larger immatures (presumably usually females) are less likely to displaced than smaller ones.[4][5][9] Dark adult red-tailed hawks appear to be harder to locate when perched than other red-tails. In Oklahoma, for example, wintering adult Harlan's hawks were rarely engaged in fights or chased by other red-tails. These hawks tended to gather in regional pockets and frequently the same ones occurred year-to-year.[77] In general, migratory behavior is complex and reliant on each individual hawk's decision-making (i.e. whether prey populations are sufficient to entice the hawk to endure prolonged snow cover).[9] During fall migration, departure may occur as soon as late September, but peak movements occur in late October and all of November in the United States, with migration ceasing after mid-December. The northernmost migrants may pass over resident red-tailed hawks in the contiguous United States, while the latter are still in the midst of brooding fledglings.[5] Not infrequently, several autumn hawk watches in Ontario, Quebec, and the northern United States record 4,500–8,900 red-tailed hawks migrating through each fall, with records of up to 15,000 in a season at Hawk Ridge hawk watch in Duluth, Minnesota.[2][78] Unlike some other Buteo spp., such as Swainson's hawks and broad-winged hawks, red-tailed hawks do not usually migrate in groups, instead passing by one-by-one, and only migrate on days when winds are favorable.[2][5] Most migrants do not move past southern Mexico in late autumn, but a few North American migrants may annually move as far south as breeding red-tailed hawks happen to occur, i.e. in Central America to as far south Panama. However, a few records were reported of wintering migrant red-tails turning up in Colombia, the first records of them anywhere in South America.[2][9][79] Spring northward movements may commence as early as late February, with peak numbers usually occurring in late March and early April. Seasonal counts may include up to 19,000 red-tails in spring at Derby Hill hawk watch, in Oswego, New York, sometimes more than 5,000 are recorded in a day there.[2][80] The most northerly migratory individuals may not reach breeding grounds until June, even adults.[2][77]
Immature hawks migrate later than adults in spring on average, but not, generally speaking, in autumn. In the northern Great Lakes, immatures return in late May to early June, when adults are already well into their nesting season and must find unoccupied ranges.[5] In Alaska, adults tend to migrate before immatures in early to mid-September, to the contrary of other areas, probably as heavy snowfall begins.[77][81] Yearlings that were banded in southwestern Idaho stayed for about 2 months after fledging, and then traveled long distances with a strong directional bias, with 9 of 12 recovered southeast of the study area- six of these moved south to coastal lowlands in Mexico] and as far as Guatemala, 4,205 km (2,613 mi) from their initial banding.[82] In California, 35 hawks were banded as nestlings; 26 were recovered at less than 50 miles away, with multidirectional juvenile dispersals. Nestlings banded in Southern California sometimes actually traveled north as far as 1,190 km (740 mi) to Oregon, ranging to the opposite extreme as far as a banded bird from the Sierra Nevadas that moved 1,700 km (1,100 mi) south to Sinaloa.[5][83] Nestlings banded in Green County, Wisconsin, did not travel very far comparatively by October–November, but by December, recoveries were found in states including Illinois, Iowa, Texas, Louisiana, and Florida.[84]
The red-tailed hawk is carnivorous, and a highly opportunistic feeder. Nearly any small animal they encounter may be viewed as potential food.[4] Their most common prey are small mammals such as rodents and lagomorphs, but they also consume birds, reptiles, fish, amphibians, and invertebrates. Prey varies considerably with regional and seasonal availability, but usually centers on rodents, accounting for up to 85% of a hawk's diet.[31] In total, nearly 500 prey species have been recorded in their diet, almost as many as great horned owls have been recorded as taking.[9][65][85][86] When 27 North American studies are reviewed, mammals make up 65.3% of the diet by frequency, 20.9% by birds, 10.8% by reptiles, 2.8% by invertebrates, and 0.2% by amphibians and fish.[5][4][85][86] The geometric mean body mass of prey taken by red-tailed hawks in North America is about 187 g (6.6 oz) based on a pair of compilation studies from across the continent, regionally varying at least from 43.4 to 361.4 g (1.53 to 12.75 oz).[87][88] Staple prey (excluding invertebrates) has been claimed to weigh from 15 to 2,114 g (0.033 to 4.661 lb), ranging roughly from the size of a small mouse or lizard to the size of a black-tailed jackrabbit (Lepus californicus).[5][9][89] The daily food requirements range from 7 to 11.2% of their own body weight, so that about three voles or the equivalent weight are required daily for a typical range adult.[39]
The talons and feet of red-tailed hawks are relatively large for a Buteo hawk; in an average-sized adult red-tail, the "hallux-claw" or rear talon, the largest claw on all accipitrids, averages about 29.7 mm (1.17 in).[32][90] In fact, the talons of red-tails in some areas averaged of similar size to those of ferruginous hawks which can be considerably heavier and notably larger than those of the only slightly lighter Swainson's hawk.[32][91][92] This species may exert an average of about 91 kg/cm2 (1,290 lbf/in2) of pressure through its feet.[32][93][94] Owing to its morphology, red-tailed hawks generally can attack larger prey than other Buteo hawks typically can, and are capable of selecting the largest prey of up to their own size available at the time of hunting, though in all likelihood numerically most prey probably weighs on average about 20% of the hawk's own weight (as is typical of many birds of prey).[9][39][95] Red-tailed hawks usually hunt by watching for prey activity from a high perch, also known as still hunting. Upon being spotted, prey is dropped down upon by the hawk. Red-tails often select the highest available perches within a given environment, since the greater the height they are at, the less flapping is required and the faster the downward glide they can attain toward nearby prey. If prey is closer than average, the hawk may glide at a steep downward angle with few flaps, if farther than average, it may flap a few swift wingbeats alternating with glides. Perch hunting is the most successful hunting method generally speaking for red-tailed hawks and can account for up to 83% of their daily activities (i.e. in winter).[9][5][96] Wintering pairs may join together and aseasonally may join forces to group hunt agile prey that they may have trouble catching by themselves, such as tree squirrels. This may consist of stalking opposites sides of a tree, to surround the squirrel and almost inevitably drive the rodent to be captured by one after being flushed by the other hawk.[5][27]
The most common flighted hunting method for red-tail is to cruise around 10 to 50 m (33 to 164 ft) over the ground with flap-and-glide type flight, interspersed occasionally with harrier-like quarters over the ground. This method is less successful than perch hunting, but seems relatively useful for capturing small birds and may show the best results while hunting in hilly country.[2][5][27] Hunting red-tailed hawks readily use trees, bushes, or rocks for concealment before making a surprise attack, even showing a partial ability to dodge among trees in an Accipiter-like fashion. Among thick stands of spruce in Alaska, a dodging hunting flight was thought to be unusually important to red-tails living in extensive areas of conifers, with hawks even coming to the ground and walking hurriedly in prey pursuit especially if the prey was large, a similar behavior to goshawks.[5][77] Additional surprisingly swift aerial hunting has reported in red-tails that habitually hunt bats in Texas. Here, the bat-hunting specialists stooped with half-closed wings, quite falcon-like, plowing through the huge stream of bats exiting their cave roosts, then zooming upwards with a bat in its talons. These hawks also flew parallel closely to the stream, then veer sharply into it and seize a bat.[97][98][99] In the neotropics, red-tails have shown the ability to dodge amongst forest canopy whilst hunting.[2][100] In Kansas, red-tailed hawks were recorded sailing to catch flying insects, a hunting method more typical of a Swainson's hawk.[101] Alternately, they may drop to the ground to forage for insects like grasshoppers and beetles as well as other invertebrates and probably amphibians and fish (except by water in the latter cases). Hunting afoot seems to be particularly prevalent among immatures. Young red-tailed hawks in northeastern Florida were recorded often extracting earthworms from near the surface of the ground and some had a crop full of earthworms after rains. Ground hunting is also quite common on Socorro Island, where no native land mammals occur, and invertebrates are more significant to their overall diet.[2][5][102] A red-tailed hawk was observed to incorporate an unconventional killing method, which was drowning a heron immediately after capture.[103] One red-tailed hawk was seen to try to grab a young ground squirrel and, upon missing it, screamed loudly, which in turn caused another young squirrel to break into a run, wherein it was captured. Whether this was an intentional hunting technique needs investigation.[27] Upon capture, smaller prey is taken to a feeding perch, which is almost always lower than a hunting perch. Among small prey, rodents are often swallowed whole, as are shrews and small snakes, while birds are plucked and beheaded. Even prey as small as chipmunks may take two or three bites to consume. Larger mammals of transportable size are at times beheaded and have part of their fur discarded, then leftovers are either stored in a tree or fall to the ground. Large prey, especially if too heavy to transport on the wing, is often dragged to a secluded spot and dismantled in various ways. If they can successfully carry what remains to a low perch, they tend to feed until full and then discard the rest.[5][4][27]
Rodents are certainly the type of prey taken most often by frequency, but their contribution to prey biomass at nests can be regionally low, and the type, variety, and importance of rodent prey can be highly variable. In total, well over 100 rodent species have turned up the diet of red-tailed hawks.[9][85][86] Rodents of extremely varied sizes may be hunted by red-tails, with species ranging in size from the 8.2 g (0.29 oz) eastern harvest mouse (Reithrodontomys humulis) to muskrats (Ondatra zibethicus), weighing some 1,135 g (2.502 lb).[104][105][106] At times, the red-tailed hawk is thought of as a semi-specialized vole-catcher, but voles are a subsistence food that is more or less are taken until larger prey such as rabbits and squirrels can be captured. In an area of Michigan, immature hawks took almost entirely voles but adults were diversified feeders.[5][39] Indeed, the 44.1 g (1.56 oz) meadow vole (Microtus pennsylvanicus) was the highest frequency prey species in 27 dietary studies across North America, accounting for up to 54% of the food at nests by frequency. It is quite rare for any one species to make up more than half of the food in any dietary study for red-tailed hawks.[5][4][85][86][107][108] In total about 9 Microtus species are known in the overall diet, with 5 other voles and lemmings known to be included in their prey spectrum.[85][86] Another well-represented species was the 27.9 g (0.98 oz) prairie vole (Microtus ochrogaster), which were the primary food, making up 26.4% of a sample of 1322, in eastern Kansas.[106] While crepuscular in primary feeding activity, voles are known to be active both day and night, and so are reliable food for hawks than most non-squirrel rodents, which generally are nocturnal in activity.[39][109][110] Indeed, most other microtine rodents are largely inaccessible to red-tailed hawks due to their strongly nocturnal foraging patterns, even though 24 species outside of voles and lemmings are known to be hunted. Woodrats are taken as important supplemental prey in some regions, being considerably larger than most other crictetid rodents, and some numbers of North American deermouse (Peromyscus maniculatus) may turn up. The largest representation of the latter species was contributing 11.9% of the diet in the Great Basin of Utah, making them the second best-represented prey species there.[85][111] Considering this limited association with nocturnal rodents, the high importance of pocket gophers in the diet of red-tailed hawks is puzzling to many biologists, as these tend to be highly nocturnal and elusive by day, rarely leaving the confines of their burrow. At least 8 species of pocket gopher are included in the prey spectrum (not to mention 5 species of pocket mice). The 110 g (3.9 oz) northern pocket gopher (Thomomys talpoides) is particularly often reported and, by frequency, even turns up as the third most often recorded prey species in 27 American dietary studies. Presumably, hunting of pocket gophers by red-tails, which has possibly never been witnessed, occurs in dim light at first dawn and last light of dusk when they luck upon a gopher out foraging.[5][85][86][112][113]
By far, the most important prey among rodents is squirrels, as they are almost fully diurnal. All told, nearly 50 species from the squirrel family have turned up as food. In particular, where they are distributed, ground squirrels are doubly attractive as a primary food source due to their ground-dwelling habits, as red-tails prefer to attack prey that is terrestrial.[9][5][85][86] There are also many disadvantages to ground squirrels as prey: they can escape quickly to the security of their burrows, they tend to be highly social and they are very effective and fast in response to alarm calls, and a good deal of species enter hibernation that in the coldest climates can range up to a 6 to 9-month period (although those in warmer climates with little to no snowy weather often have brief dormancy and no true hibernation). Nonetheless, red-tailed hawks are devoted predators of ground squirrels, especially catching incautious ones as they go out foraging (which more often than not are younger animals).[114][115][116][117] A multi-year study conducted on San Joaquin Experimental Range in California, seemingly still the largest food study to date done for red-tailed hawks with 4031 items examined, showed that throughout the seasons the 722 g (1.592 lb) California ground squirrel (Otospermophilus beecheyi) was the most significant prey, accounting for 60.8% of the breeding season diet and about 27.2% of the diet for hawks year-around. Because of the extremely high density of red-tailed hawks on this range, some pairs came to specialize in diverse alternate prey, which consisted variously of kangaroo rats, lizards, snakes or chipmunks. One pair apparently lessened competition by focusing on pocket gophers instead despite being near the center of ground squirrel activity.[118][119] In Snake River NCA, the primary food of red-tailed hawks was the 203.5 g (7.18 oz) Townsend's ground squirrel (Urocitellus townsendii), which made up nearly 21% of the food in 382 prey items across several years despite sharp spikes and crashes of the ground squirrel population there.[89][120] The same species was the main food of red-tailed hawks in southeastern Washington, making up 31.2% of 170 items.[121] An even closer predatory relationship was reported in the Centennial valley of Montana and south-central Montana, where 45.4% of 194 prey items and 40.2% of 261 items, respectively, of the food of red-tails consisted of the 455.7 g (1.005 lb) Richardson's ground squirrel (Urocitellus richardsonii).[91][122][123] Locally in Rochester, Alberta, Richardson's ground squirrel, estimated to average 444 g (15.7 oz), were secondary in number to unidentified small rodents but red-tails in the region killed an estimated 22–60% of the area’s ground squirrel, a large dent in the squirrel’s population.[124] Further east, ground squirrels are not so reliably distributed, but one study in southern Wisconsin, in one of several quite different dietary studies in that state, the 172.7 g (6.09 oz) thirteen-lined ground squirrel (Ictidomys tridecemlineatus) was the main prey species, making up 29.7% of the diet (from a sample of 165).[125][126]
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In Kluane Lake, Yukon, 750 g (1.65 lb) Arctic ground squirrels (Spermophilus parryii) were the main overall food for Harlan’s red-tailed hawks, making up 30.8% of a sample of 1074 prey items. When these ground squirrels enter their long hibernation, the breeding Harlan’s hawks migrate south for the winter.[127] Nearly as important in Kluane Lake was the 200 g (7.1 oz) American red squirrel (Tamiasciurus hudsonicus), which constituted 29.8% of the above sample. Red squirrels are highly agile dwellers on dense spruce stands, which has caused biologists to ponder how the red-tailed hawks are able to routinely catch them. It is possible that the hawks catch them on the ground such as when squirrels are digging their caches, but theoretically, the dark color of the Harlan’s hawks may allow them to ambush the squirrels within the forests locally more effectively.[5][126][127] While American red squirrels turn up not infrequently as supplementary prey elsewhere in North America, other tree squirrels seem to be comparatively infrequently caught, at least during the summer breeding season. It is known that pairs of red-tailed hawks will cooperatively hunt tree squirrels at times, probably mostly between late fall and early spring. Fox squirrels (Sciurus niger), the largest of North America’s tree squirrels at 800 g (1.8 lb), are fairly common supplemental prey but the lighter, presumably more agile 533 g (1.175 lb) eastern gray squirrel (Sciurus carolinensis) appears to be seldom caught based on dietary studies.[9][84][125][126][128] While adult marmot may be difficult for red-tailed hawks to catch, young marmots are readily taken in numbers after weaning, such as a high frequency of yellow-bellied marmot (Marmota flaviventris) in Boulder, Colorado.[129] Another grouping of squirrels but at the opposite end of the size spectrum for squirrels, the chipmunks are also mostly supplemental prey but are considered more easily caught than tree squirrels, considering that they are more habitual terrestrial foragers.[5][4][85] In central Ohio, eastern chipmunks (Tamias striatus), the largest species of chipmunk at an average weight of 96 g (3.4 oz), were actually the leading prey by number, making up 12.3% of a sample of 179 items.[128][130]
Outside of rodents, the most important prey for North American red-tailed hawks is rabbits and hares, of which at least 13 species are included in their prey spectrum. By biomass and reproductive success within populations, these are certain to be their most significant food source (at least in North America).[9][85] Adult Sylvilagus rabbits known to be hunted by red-tails can range from the 700 g (1.5 lb) brush rabbit (Sylvilagus bachmani) to the Tres Marias rabbit (Sylvilagus graysoni) at 1,470 g (3.24 lb) while all leporids hunted may range the 421.3 g (14.86 oz) pygmy rabbit (Brachylagus idahoensis) to hares and jackrabbits potentially up twice the hawk’s own weight.[131][132][133][42] While primarily crepuscular in peak activity, rabbits and hares often foraging both during day and night and so face almost constant predatory pressure from a diverse range of predators. Male red-tailed hawks or pairs which are talented rabbit hunters are likely have higher than average productivity due to the size and nutrition of the meal ensuring healthy, fast-growing offspring.[5][9][39][134] Most widely reported are the cottontails, which the three most common North America varieties softly grading into mostly allopatric ranges, being largely segregated by habitat preferences where they overlap in distribution. Namely, in descending order of reportage were: the eastern cottontail (Sylvilagus floridanus), the second most widely reported prey species overall in North America and with maximum percentage known in a given study was 26.4% in Oklahoma (out of 958 prey items), the mountain cottontail (Sylvilagus nuttallii), maximum representation being 17.6% out of a sample of 478 in Kaibab Plateau, Arizona and the desert cottontail (Sylvilagus audubonii), maximum representation being 22.4% out of a sample of 326 in west-central Arizona.[85][122][135][136] Black-tailed jackrabbits (Lepus californicus) are even more intensely focused upon as a food source by the hawks found in the west, particularly the Great Basin. This species is likely the largest prey routinely hunted by red-tails, and the mean prey size where jackrabbits are primarily hunted is the highest known overall. When jackrabbit numbers crash, red-tailed hawk productivity tends to decline as well. In northern Utah, black-tailed jackrabbits made up 55.3% by number of a sample of 329. Elsewhere, they are usually somewhat secondary by number. While mostly juvenile and yearling jackrabbits are caught, they occasionally take adult jackrabbits approximately up to 2,114 g (4.661 lb) in weight.[85][121][89][111] Other even larger species are sometimes taken as prey such as the white-tailed jackrabbit (Lepus townsendii), but whether this includes healthy adults, as they average over 3,200 g (7.1 lb), is unclear.[91]
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In the boreal forests of Canada and Alaska, red-tails are fairly dependent on the snowshoe hare (Lepus americanus), falling somewhere behind the great horned owl and ahead of the northern goshawk in their regional reliance on this food source.[77][127][124] The hunting preferences of red-tails who rely on snowshoe hares are variable. In Rochester, Alberta, 52% of snowshoe hares caught were adults, such prey estimated to average 1,287 g (2.837 lb), and adults, in some years, were six times more often taken than juvenile hares, which averaged an estimated 560 g (1.23 lb). 1.9–7.1% of adults in the regional population of Rochester were taken by red-tails, while only 0.3–0.8 of juvenile hares were taken by them. Despite their reliance on it, only 4% (against 53.4% of the biomass) of the food by frequency here was made up of hares.[124] On the other hand, in Kluane Lake, Yukon, juvenile hares were taken roughly 11 times more often than adults, despite the larger size of adults here, averaging 1,406.6 g (3.101 lb), and that the overall prey base was less diverse at this more northerly clime. In both Rochester and Kluane Lake, the number of snowshoe hares taken was considerably lower than the number of ground squirrels taken. The differences in average characteristics of snowshoe hares that were hunted may be partially due to habitat (extent of bog openings to dense forest) or topography.[127][137] Another member of the Lagomorpha order has been found in the diet, the much smaller American pika (Ochotona princeps), at 150 g (5.3 oz), but is not known to be common prey.[138]
A diversity of mammals may be consumed opportunistically outside of the main food groups of rodents and leporids, but usually occur in low numbers. At least five species each are taken of shrews and moles, ranging in size from their smallest mammalian prey, the cinereus (Sorex cinereus) and least shrews (Cryptotis parva), which both weigh about 4.4 g (0.16 oz), to Townsend's mole (Scapanus townsendii), which weighs about 126 g (4.4 oz).[85][86][139][140][141][142] A respectable number of the 90 g (3.2 oz) eastern mole (Scalopus aquaticus) were recorded in studies from Oklahoma and Kansas.[85][106] Four species of bat have been recorded in their foods.[85][118] The red-tailed hawks local to the large cave colonies of 12.3 g (0.43 oz) Mexican free-tailed bats (Tadarida brasiliensis) in Texas can show surprising agility, some of the same hawks spending their early evening and early morning hours in flight patrolling the cave entrances in order to stoop suddenly on these flighted mammals.[97][98][143] Larger miscellaneous mammalian prey are either usually taken as juveniles, like the nine-banded armadillo (Dasypus novemcinctus), or largely as carrion, like the Virginia opossum (Didelphis virginiana).[142][144] Small carnivorans may be taken, usually consisting of much smaller mustelids, like the least weasels (Mustela nivalis), stoats (Mustela erminea), and long-tailed weasels (Neogale frenata).[85][89][135][145] slightly larger carnivores, such as small Indian mongooses (Herpestes auropunctatus), ringtails (Bassariscus astutus), small American minks (Neovison vison) and even adult striped skunk (Mephitis mephitis), which can be much larger than a fully grown hawk, was reportedly taken by red-tailed hawks.[146][135][147][148] Additionally, red-tailed hawks are considered as potential predators of white-nosed coati (Nasua narica) and kit fox (Vulpes macrotis)[149][150] Remains of exceptionally large carnivoran species, such as domestic cats (Felis catus), red fox ( Vulpes vulpes) and common raccoon (Procyon lotor) are sometimes found amongst their foods, but most are likely taken as juveniles or consumed only as carrion. [86][129][151] Many of these medium-sized carnivorans are probably visited as roadkill, especially during the sparser winter months, but carrion has turned up more widely than previously thought. Some nests have been found (to the occasional "shock" of researchers) with body parts from large domestic stock like sheep (Ovis aries), pigs (Sus domesticus), horses (Equus caballus ) and cattle (Bos taurus) (not to mention wild varieties like deer), which red-tails must visit when freshly dead out on pastures and take a couple of talonfuls of meat.[5][135][118][151] In one instance, a red-tailed hawk was observed to kill a small but seemingly healthy lamb. These are born heavier than most red-tails at 1,500 g (3.3 lb) but in this case, the hawk was scared away before it could consume its kill by the rifle fire of the shepherd who witnessed the instance.[152]
Like most (but not all) Buteo hawks, red-tailed hawks do not primarily hunt birds in most areas, but can take them fairly often whenever they opportune upon some that are vulnerable. Birds are, by far, the most diverse class in the red-tailed hawk’s prey spectrum, with well over 200 species known in their foods.[65][85][86] In most circumstances where birds become the main food of red-tailed hawks, it is in response to ample local populations of galliforms. As these are meaty, mostly terrestrial birds which usually run rather than fly from danger (although all wild species in North America are capable of flight), galliforms are ideal avian prey for red-tails. Some 23 species of galliforms are known to be taken by red-tailed hawks, about a third of these being species introduced by humans.[85][86] Native quails of all five North American species may expect occasional losses.[118][153][154] All 12 species of grouse native to North America are also occasionally included in their prey spectrum.[127][91][155][156][157][158][159][160][161] In the state of Wisconsin, two large studies, from Waupun and Green County, found the main prey species to be the ring-necked pheasant (Phasianus colchicus), making up 22.7% of a sample of 176 and 33.8% of a sample of 139, respectively.[84][162] With a body mass averaging 1,135 g (2.502 lb), adult pheasants are among the largest meals that male red-tails are likely to deliver short of adult rabbits and hares and therefore these nests tend to be relatively productive. Despite being not native to North America, pheasants usually live in a wild state. Chickens (Gallus gallus domesticus) are also taken throughout North America,[163] with all Wisconsin studies also found large numbers of them, making up as much as 14.4% of the diet. Many studies reflect that free-ranging chickens are vulnerable to red-tailed hawks although somewhat lesser numbers are taken by them overall in comparison to nocturnal predators (i.e. owls and foxes) and goshawks.[84][88][162] In Rochester, Alberta, fairly large numbers of ruffed grouse (Bonasa umbellus) were taken but relatively more juveniles were taken of this species than the two other main contributors to biomass here, snowshoe hare and Townsend’s ground squirrel, as they are fairly independent early on and more readily available. Here the adult grouse was estimated to average 550 g (1.21 lb) against the average juvenile which in mid-summer averaged 170 g (6.0 oz).[124]
Beyond galliforms, three other quite different families of birds make the most significant contributions to the red-tailed hawk’s avian diet. None of these three families are known as particularly skilled or swift fliers, but are generally small enough that they would generally easily be more nimble in flight. One of these are the woodpeckers, if only for one species, the 131.6 g (4.64 oz) northern flicker (Colaptes auratus), which was the best represented bird species in the diet in 27 North American studies and was even the fourth most often detected prey species of all.[5][4][85][86] Woodpeckers are often a favorite in the diet of large raptors as their relatively slow, undulating flight makes these relatively easy targets. The flicker in particular is a highly numerous species that has similar habitat preferences to red-tailed hawks, preferring fragmented landscapes with trees and openings or parkland-type wooded mosaics, and often forage on the ground for ants, which may make them even more susceptible.[164][165] Varied other woodpecker species may turn up in their foods, from the smallest to the largest extant in North America, but are much more infrequently detected in dietary studies.[142][166] Another family relatively often selected prey family are corvids, which despite their relatively large size, formidable mobbing abilities and intelligence are also slower than average fliers for passerines. 14 species of corvid are known to fall prey to red-tailed hawks.[85][86][167] In the Kaibab Plateau, the 128 g (4.5 oz) Steller's jay (Cyanocitta stelleri) were the fourth most identified prey species (10.3% of the diet).[135] 453 g (0.999 lb) American crows are also regularly detected supplemental prey in several areas.[84][122][162] Even the huge common raven (Corvus corax), at 1,050 g (2.31 lb) at least as large as red-tailed hawk itself, may fall prey to red-tails, albeit very infrequently and only in a well-staged ambush.[135] One of the most surprising heavy contributors are the icterids, despite their slightly smaller size and tendency to travel in large, wary flocks, 12 species are known to be hunted.[85][86] One species pair, the meadowlarks, are most often selected as they do not flock in the same ways as many other icterids and often come to the ground, throughout their life history, rarely leaving about shrub-height. The 100.7 g (3.55 oz) western meadowlark (Sturnella neglecta), in particular, was the third most often detected bird prey species in North America.[5][4][85][86][89] Red-winged blackbirds (Agelaius phoeniceus) which are probably too small, at an average weight of 52.4 g (1.85 oz), and fast for a red-tailed hawk to ever chase on the wing (and do travel in huge flocks, especially in winter) are nonetheless also quite often found in their diet, representing up to 8% of the local diet for red-tails. It is possible that males, which are generally bold and often select lofty perches from which to display, are most regularly ambushed.[5][162] One bird species that often flocks with red-winged blackbirds in winter is even better represented in the red-tail’s diet, the non-native 78 g (2.8 oz) European starling (Sturnus vulgaris), being the second most numerous avian prey species and seventh overall in North America.[85][86] Although perhaps most vulnerable when caught unaware while calling atonally on a perch, a few starlings (or various blackbirds) may be caught by red-tails which test the agile, twisting murmurations of birds by flying conspicuously towards the flock, to intentionally disturb them and possibly detect lagging, injured individual birds that can be caught unlike healthy birds. However, this behavior has been implied rather than verified.[5][118]
Over 50 passerine species from various other families beyond corvids, icterids and starlings are included in the red-tailed hawks' prey spectrum but are caught so infrequently as to generally not warrant individual mention.[85][86] Non-passerine prey taken infrequently may include but are not limited to pigeons and doves, cuckoos, nightjars, kingfishers and parrots.[9][89][118][168][169][170][171] However, of some interest, is the extreme size range of birds that may be preyed upon. Red-tailed hawks in Caribbean islands seem to catch small birds more frequently due to the paucity of vertebrate prey diversity here. Birds as small as the 7.7 g (0.27 oz) elfin woods warbler (Setophaga angelae) and the 10 g (0.35 oz) bananaquit (Coereba flaveola) may turn up not infrequently as food. How red-tails can catch prey this small and nimble is unclear (perhaps mostly the even smaller nestlings or fledglings are depredated).[5][9][100] In California, most avian prey was stated to be between the size of a starling and a quail.[5][118] Numerous water birds may be preyed upon including at least 22 species of shorebirds, at least 17 species of waterfowl, at least 8 species of heron and egrets and at least 8 species of rails, plus a smaller diversity of grebes, shearwaters and ibises.[5][85][86][172] These may range to as small as the tiny, mysterious and "mouse-like" black rail (Laterallus jamaicensis), weighing an average of 32.7 g (1.15 oz), and snowy plover (Charadrius nivosus), weighing an average of 42.3 g (1.49 oz) (how they catch adults of this prey is not known), to some gulls, ducks and geese as heavy or heavier than a red-tailed hawk itself.[173][174]
How large of a duck that red-tailed hawks can capture may be variable. In one instance, a red-tailed hawk failed to kill a healthy drake red-breasted merganser (Mergus serrator), with this duck estimated to weigh 1,100 g (2.4 lb), later the same red-tail was able to dispatch a malnourished red-necked grebe (Podiceps grisegena) (a species usually about as heavy as the merganser), weighing an estimated 657 g (1.448 lb).[175] However, in interior Alaska, locally red-tailed hawks have become habitual predators of adult ducks, ranging from 345 g (12.2 oz) green-winged teal (Anas carolinensis) to 1,141 g (2.515 lb) mallard (Anas platyrhynchos).[77] Even larger, occasionally adult Ross's goose (Chen rossii), weighing on average 1,636 g (3.607 lb), have been killed as well.[176] Also, a non-native Egyptian goose (Alopochen aegyptiaca), in which adults average 1,762 g (3.885 lb), was killed by a red-tail in Texas.[177] There are several known instances of predation on young greater sage grouse (Centrocercus urophasianus), and predation on an adult female, weighing 1,500 g (3.3 lb) have been reported.[155] Even larger, in at least one case a grown hatch-year bird was caught of the rare, non-native Himalayan snowcock (Tetraogallus himalayensis), this species averaging 2,428 g (5.353 lb) in adults.[178] Red-tailed hawks are a threat to the poults typically of the wild turkey (Meleagris gallopavo), which weighed up to at least 1,500 g (3.3 lb).[179] In one instance, a red-tailed hawk was observed trying to attack an adult female turkey, but not succeed at dispatching her.[180] Additionally, young domestic turkeys, Other than wild turkeys, other larger birds occasionally lose young to red-tails such as trumpeter swans (Cygnus buccinator), sandhill cranes (Grus canadensis) and great blue herons (Ardea herodias).[181][182]
Early reports claimed relatively little predation of reptiles by red-tailed hawks but these were regionally biased towards the east coast and the upper Midwest of the United States.[183] However, locally the predation on reptiles can be regionally quite heavy and they may become the primary prey where large, stable numbers of rodents and leporids are not to be found reliably. Nearly 80 species of reptilian prey have been recorded in the diet at this point.[5][85][86] Most predation is on snakes, with more than 40 species known in the prey spectrum. The most often found reptilian species in the diet (and sixth overall in 27 North American dietary studies) was the gopher snake (Pituophis catenifer). Red-tails are efficient predators of these large snakes, which average about 532 to 747 g (1.173 to 1.647 lb) in adults, although they also take many small and young gopher snakes.[89][121][184][185][186][187] Along the Columbia River in Washington, large colubrid snakes were found to be the primary prey, with the eastern racer (Coluber constrictor), which averages about 556 g (1.226 lb) in mature adults, the most often recorded at 21.3% of 150 prey items, followed by the gopher snake at 18%. This riverine region lacks ground squirrels and has low numbers of leporids. 43.2% of the overall diet here was made up of reptiles, while mammals, made up 40.6%.[184][188] In the Snake River NCA, the gopher snake was the second most regularly recorded (16.2% of 382 items) prey species over the course of the years, and did not appear to be subject to the extreme population fluctuations of mammalian prey here.[89] Good numbers of smaller colubrids can be taken as well, especially garter snakes.[85][91][106] Red-tailed hawks may engage in avoidance behavior to some extent with regard to venomous snakes. For example, on the San Joaquin Experimental Range in California, they were recorded taking 225 gopher snakes against 83 western rattlesnakes (Crotalus oreganus). Based on surveys, however, the rattlesnakes were five times more abundant on the range than the gopher snakes.[5][118] Nonetheless, at least 15 venomous snakes have been recorded in the red-tailed hawk’s diet.[85][86] The smallest known snake known to be hunted by red-tailed hawks is the 6 g (0.21 oz) redbelly snake (Storeria occipitomaculata).[189] Red-tailed hawks have been seen flying off with snake prey that may exceed 153 cm (5 ft 0 in) in length in some cases.[9] One red-tail was photographed killing a "fairly large" eastern diamondback rattlesnake (Crotalus adamanteus), this being North America’s heaviest snake and the heaviest venomous snake in the Americas at a large mature size of about 2,300 g (5.1 lb).[16][190] For the eastern indigo snakes (Drymarchon couperi), North America’s longest native snake, usually young and small ones are at risk.[191]
In North America, fewer lizards are typically recorded in the foods of red-tailed hawk than are snakes, probably because snakes are considerably better adapted to cooler, seasonal weather, with an extensive diversity of lizards found only in the southernmost reaches of the contiguous United States. A fair number of lizards were recorded in the diet in southern California and red-tails can be counted among the primary predatory threats to largish lizards in the United States such as the 245 g (8.6 oz) common chuckawalla (Sauromalus ater).[86][118][192][193] However, the red-tailed hawks ranging into the neotropics regularly take numerous species of lizards. This is especially true of hawks living on islands that are not naturally colonized by small mammals. Insular red-tails commonly pluck up mostly tiny anoles, that may average only 1.75 to 43.5 g (0.062 to 1.534 oz) in adult mass, depending on species.[9][100][194] Not all tropical lizards taken by red-tailed hawks are so dainty red-tailed hawks can prey on capable of taking lizards as large as Cape spinytail iguanas (Ctenosaura hemilopha) and green iguanas (Iguana iguana) that usually weighs between 700 to 1,000 g (1.5 to 2.2 lb) and around 1,530 g (3.37 lb) respectively.[195][196][197] Beyond snakes and lizards, there are a few cases of red-tailed hawks preying on baby or juvenile turtles, i.e. the gopher tortoise (Gopherus polyphemus), the desert tortoise (Gopherus agassizii) and the common snapping turtle (Chelydra serpentina).[142][198]
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Records of predation on amphibians is fairly infrequent. It is thought that such prey may be slightly underrepresented, as they are often consumed whole and may not leave a trace in pellets. Their fine bones may dissolve upon consumption.[5][85][183] So far as is known, North American red-tailed hawks have preyed upon 9 species of amphibian, four of which are toads. Known amphibian prey has ranged to as small as the 0.75 g (0.026 oz) red-backed salamander (Plethodon cinereus), the smallest known vertebrate prey for red-tailed hawks, to the 430 g (15 oz) American bullfrog (Lithobates catesbeianus).[125][142][199] Invertebrates, mostly represented by insects like beetles and crickets, are better represented in the stomach contents of red-tailed hawks than their pellets or prey remains.[5][183] It is possible some invertebrate prey is ingested incidentally, as in other various birds of prey, they can in some cases be actually from the stomachs of birds eaten by the raptor.[2][5] However, some red-tails, especially immatures early in their hunting efforts, often do spend much of the day on the ground grabbing terrestrial insects and spiders.[5][85][183][200][201] The red-tailed hawks of Puerto Rico frequently consume Puerto Rican freshwater crabs (Epilobocera sinuatifrons), which average 9.4 g (0.33 oz).[9][100][202] Other island populations, such as those on Socorro island, also feed often on terrestrial crabs, here often blunting their claws while catching them.[27] Fish are the rarest class of prey based on dietary studies. Among the rare instances of them capturing fish have included captures of wild channel catfish (Ictalurus punctatus), non-native common carp (Cyprinus carpio) and ornamental koi (Cyprinus rubrofuscus) as well some hawks that were seen scavenging on dead chum salmon (Oncorhynchus keta).[86][203][204]
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As easily one of the most abundant of all American raptorial birds, red-tailed hawks have been recorded as interacting with every other diurnal bird of prey. Due to the extreme dietary plasticity of red-tails, the food habits of other birds of prey regularly overlap considerably with red-tails. Furthermore, due to its ability to nest in varied habitats, home ranges also frequently abut those of other raptor species.[5][9] The most obvious similar species in their range are other Buteo hawks, especially larger species with a similar ecological niche. Two of the larger, more widespread other Buteos are the Swainson's hawk and the ferruginous hawks and, as with many other birds of prey, red-tailed hawks occur in almost the entirety of these birds' breeding ranges.[9][205] These species have broadly similar breeding season diets, especially the ferruginous and red-tailed hawks. In some areas, such as Snake River NCA the diets of the two species consist of more than 90% of the same species and body mass of prey taken was similar.[89][91] Therefore, all three large Buteo hawks defend their territories from each other with almost the same degree of dedication that they defend from others of their own species. In some cases, territorial clashes of Swainson's hawks and red-tailed hawks can last up to 12 hours, however, the birds involved are usually careful to avoid physical contact.[5][206] Due to the similarities of the foods and their aggressive dispositions towards one another, these Buteos need some degree of partitioning in order to persist alongside one another and this usually is given by habitat preferences. The ferruginous hawk prefers open, practically treeless prairie while of these, the red-tailed hawks prefers the most wooded areas with large trees, while the Swainson's hawk prefer roughly intermediate areas.[91][206][8] Where the habitat is more open, such as in Cassia County, Idaho, the Swainson's and ferruginous hawks have the advantage in numbers and red-tails are scarce.[207] However, habitat alterations by humans, such as fire suppression and recovering pasture, usually favor the red-tailed hawk and are to the detriment of the other two species.[205][208][64] These practices have caused range expansions of many other species of birds but declines in many others.[209][210][211] Of these three Buteo species, the Swainson's hawk is most dissimilar, being a long-distance migrant which travels to South America each winter and, for much of the year, prefers to prey on insects (except for during breeding, when more nutritious food such as ground squirrels are mainly fed to the young). It also breeds notably later than the other two species.[212] Surprisingly, although it's slightly smaller in body mass and has notably smaller (and presumably weaker) feet than ferruginous and red-tailed hawks, the Swainson's is actually usually (but not invariably) dominant in territorial conflicts over the other two. Part of this advantage is that the Swainson's hawk is apparently a superior flier both in long and short-distance flights, with its more pointed wing shape and lower wing loading allowing it more agile, sustained and speedier flight that the bulkier hawks cannot match.[213] Therefore, in north-central Oregon, Swainson's hawks were shown to be more productive, in prairie located trees, and partially displaced prior-breeding red-tails several times, although overall breeding success rates were not perceptibly decreased in the latter hawk.[206][214] In the Chihuahuan Desert of Mexico, Swainson's hawks usually nested in lowlands and red-tails nested in highlands but interspecies conflicts nevertheless were apparently quite frequent. Usually, the habitat preferences of red-tailed hawks and ferruginous hawks are discrepant enough to keep serious territorial conflicts to a minimum.[89][206] However, red-tailed hawks and ferruginous hawks occasionally engaged in kleptoparasitism towards one another, usually during winter. Red-tails may be somewhat dominant based on prior reports in food conflicts but the ferruginous hawk may also win these.[4] Where they overlap, the hawk species may adjust their daily routine to minimize contact, which tends to be costly of time and energy and may cause the hawks to abandon their nests for long stretches of time, which in turn leaves their young vulnerable to predation.[5] When habitats change rapidly, often due to human interference, and they nest more closely than natural partitioning would allow, in all three nesting success can decline significantly.[8]
Beyond the Swainson's and ferruginous hawks, six other Buteos co-occur with red-tailed hawks in different parts of North America. Many of these are substantially smaller than red-tails and most serious territorial conflicts with them are naturally mitigated by nesting in deeper wooded areas.[65][205] One other larger species, the rough-legged buzzard, mostly nests far north of the breeding range of red-tailed hawks. However, in Alaska they sometimes nest in the same areas. The rough-legged buzzards are both cliff and tree nesters and areas used by the two species are not necessarily mutually exclusive but each seems to avoid the other, in part by differing breeding schedules.[215] Wintering rough-legged buzzards may regularly come into conflict over food with red-tailed hawks and seem to be subordinate to the red-tails, with several records of them being chased off both kills and carrion by the red-tailed hawks. During winter their hunting habits may keep them somewhat separate, the rough-legged being a much more aerial hunter, but rough-legged buzzards usually withdrew if a red-tailed hawk flew towards them. There is at least one case, however, of a rough-legged buzzard being the victor of a conflict over a kill with a red-tailed hawk.[77][151] Red-tailed hawks are conspicuously more aggressive and tend to be dominant over slenderer, medium-sized Buteos such as red-shouldered hawks and zone-tailed hawks (Buteo albonotatus).[27] In Massachusetts, red-shoulder hawks used mixed forests and hardwoods as nesting habitat while red-tails most often used in pitch pine and stunted oaks on Cape Cod. Nesting range overlap here most often occurred on white pine forests. As habitat has opened over time, red-tailed hawks frequently took over former red-shouldered hawk territories, even using their nests in two cases.[5][65] In north-central Florida, it was found during winter that red-shouldered and red-tailed hawk habitat usage blurred and, because the local habitat favors red-shouldered hawks, they easily outnumbered the number of red-tailed hawks in the area. Therefore, again with sufficient habitat partitioning, the two species can live near one another without negatively effecting one another.[216] In the American southwest and Texas, two relatively large buteonine hawks also live alongside red-tailed hawks, the Harris's hawk (Parabuteo unicinctus) and the white-tailed hawk (Geranoaetus albicaudatus). Usually, habitat preferences kept conflicts to a minimum, with the red-tailed hawk favoring taller, more isolated saguaro cactus for nesting, whereas the other species outnumbered red-tails in areas that were denser and more shrubby.[217][218] The Harris's hawk was determined to be a superior aerial hunter over red-tailed hawks, and could take down flying birds more routinely.[217]
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Hawks and kites from outside the buteonine lineage are usually substantially smaller or at least different enough in diet and habitat to largely avoid heavy conflict with red-tailed hawks. On occasion, northern harriers (Circus hudsonius) which have much lower wing loading, will mob red-tailed hawks out of their home ranges but in winter the red-tails seem to be dominant over them in conflicts over food.[151][219] Among Accipiter hawks, the most similar to the red-tailed hawk in diet and size is the northern goshawk. In some areas, the prey species of these can be very similar and North American populations of goshawks take many more squirrels and leporids than their Eurasian counterparts do.[127][220] It was found that the feet and striking force of hunting goshawks was more powerful than that of the red-tailed hawk, despite the red-tails being up to 10% heavier in some parts of North America.[94] Therefore, wild goshawks can dispatch larger prey both on average and at maximum prey size, with some victims of female goshawks such as adult hares and galliforms such as turkey and capercaillie weighing up to or exceeding roughly 4,000 g (8.8 lb).[221][222][223] In a comparative study in the Kaibab Plateau of Arizona, however, it was found that red-tailed hawks had several population advantages. Red-tails were more flexible in diet, although there was a very broad overlap in prey species selected, and nesting habitat than the goshawks were.[135] As red-tailed hawks in conflict with other more closely related Buteo hawks rarely (if ever) result in mortality on either side, goshawks and red-tailed hawks do seem to readily kill one another. Adults of both species have been shown to be able to kill adults of the other.[124][224][225][226]
The great horned owl occupies a similar ecological niche nocturnally to the red-tailed hawk.[88] There have been many studies that have contrasted the ecology of these two powerful raptors.[39][84][128] The great horned owl averages heavier and larger footed, with northern populations averaging up to 26% heavier in the owl than the hawk.[39] However, due in part to the red-tail’s more extensive access to sizable prey such as ground squirrels, several contrasting dietary studies found that the estimated mean prey size of the red-tailed hawk, at 175 g (6.2 oz), was considerably higher than that of the great horned owl, at 76 g (2.7 oz).[88] Also, the diet of red-tailed hawk seems to be more flexible by prey type, as only just over 65% of their diet is made of mammals, whereas great horned owls were more restricted feeders on mammals, selecting them 87.6% of the time.[85][86][227] However, the overall prey spectrum of great horned owls includes more species of mammals and birds (but far less reptiles) and the great horned owl can attack prey of a wider size range, including much larger prey items than any taken by red-tailed hawks. Mean prey weights in different areas for great horned owls can vary from 22.5 to 610.4 g (0.79 to 21.53 oz), so is far more variable than that of red-tailed hawks (at 43.4 to 361.4 g (1.53 to 12.75 oz)) and can be much larger (by about 45%) than the largest estimated size known for the red-tailed hawk's mean prey weight but conversely the owl can also subsist on prey communities averaging much smaller in body size than can support the hawk.[228][229] Some prey killed by great horned owls was estimated to weigh up to 6,800 g (15.0 lb).[85][227][230] Great horned owls and red-tailed hawks compete not only for food but more seriously over nesting areas and home ranges. Great horned owls are incapable of constructing nests and readily expropriate existing red-tail nests. The habitat preferences of the two species are quite similar and the owl frequently uses old red-tail nests, but they do seem to prefer more enclosed nest locations where available over the generally open situation around red-tailed hawk nests. Sometimes in warmer areas, the owls may nest sufficiently early to have fledged young by the time red-tails start to lay. However, when there is a temporal overlap in reproductive cycles, the owl sometimes takes over an occupied red-tail nest, causing desertion. Red-tailed hawks have an advantage in staple prey flexibility as aforementioned, while great horned owl populations can be stressed when preferred prey is scarce, especially when they rely on leporids such as hares and jackrabbits.[5][88][127][111] For example, in Alberta, when snowshoe hares were at their population peak, red-tailed hawks did not increase in population despite taking many, with only a slight increase in mean clutch size, whereas the owls fluctuated in much more dramatic ways in accordance with snowshoe hare numbers. The red-tails migratory behavior was considered as the likely cause of this lack of effect, whereas great horned owls remained through the winter and was subject to winter-stress and greater risk of starvation.[231] As a nester, great horned owl has the advantage in terms of flexibility, being somewhat spread more evenly across different habitats whereas in undisturbed areas, red-tailed hawks seem to nest more so in clusters where habitat is favorable.[5][84][128][231] Predatory relationships between red-tailed hawks and great horned owls are quite one-sided, with the great horned owl likely the overall major predator of red-tails. On the other hand, red-tailed hawks are rarely (if ever) a threat to the great horned owl. Occasionally a red-tailed hawk can strike down an owl during the day but only in a few singular cases has this killed an owl.[232][233] Most predation by the owls on the hawks is directed at nestlings at the point where the red-tails' nestlings are old enough that the parents no longer roost around the nest at night. Up to at least 36% of red-tailed hawk nestlings in a population may be lost to great horned owls.[5][124] Adult and immature red-tailed hawks are also occasionally preyed upon at night by great horned owls in any season. In one case, a great horned owl seemed to have ambushed, killed and fed upon a full-grown migrating red-tail even in broad daylight.[5][65] Occasionally, both red-tails and great horned owls will engage each other during the day and, even though the red-tailed hawk has the advantage at this time of day, either may succeed in driving away the other.[4][65][231] Despite their contentious relations, the two species may nest quite close to one another. For example, in Saskatchewan, the smallest distance between nests was only 32 to 65 m (105 ft 0 in to 213 ft 3 in). In these close proximity areas all owl nests succeeded while only two red-tail nests were successful.[234] In Waterloo, Wisconsin, the two species were largely segregated by nesting times, as returning red-tailed hawks in April–June were usually able to successfully avoid nesting in groves holding great horned owls, which can begin nesting activities as early as February.[235] In Delaware County, Ohio and in central New York state, divergence of hunting and nesting times usually allowed both species to succeed in nesting. In all three areas, any time the red-tails tried to nest closer to great horned owls, their breeding success rates lowered considerably. It is presumable that sparser habitat and prey resources increased the closeness of nesting habits of the two species, to the detriment of the red-tails. Due to nesting proximity to great horned owls, mature red-tails may have losses ranging from 10 to 26%.[124][128][234][236]
Red-tailed hawks may face competition from a very broad range of predatory animals, including birds outside of typically active predatory families, carnivoran mammals and some reptiles such as snakes. Mostly these diverse kinds of predators are segregated by their hunting methods, primary times of activity and habitat preferences. In California, both the red-tails and western diamondback rattlesnakes (Crotalus atrox) live mainly on California ground squirrel, but the rattlesnake generally attacks the squirrels in and around their burrows, whereas the hawks must wait until they leave the burrows to capture them.[237] Hawks have been observed following American badgers (Taxidea taxus) to capture prey they flush and the two are considered potential competitors, especially in sparse sub-desert areas where the rodent foods they both favor are scarce.[238] Competition over carcasses may occur with American crows, and several crows, usually about six or more, working together can displace a hawk.[239] Another avian scavenger, the turkey vulture (Cathartes aura), is dominated by red-tails and may be followed by red-tails in order to supplant a carcass found by the vulture with their keen sense of smell.[240] In some cases, red-tailed hawks may be considered lessened as food competitors by their lack of specialization. For instance, no serious competition probably occurs between them and Canada lynx (Lynx canadensis) despite both living on snowshoe hares.[241]
Distinguishing territorial exclusionary behavior and anti-predator behavior is difficult in raptorial birds. However, as opposed to other medium to largish hawks which chase off red-tails most likely as competition, in much smaller raptors such as kestrels and smaller Accipiter hawks, their aggressive reaction to red-tailed hawks is almost certainly an anti-predator behavior. Although less prolific than goshawks, some eagles and, especially, great horned owls, red-tailed hawks can and do prey upon smaller birds of prey. The following species of accipitrid have been known to fall prey to red-tailed hawks, potentially including nestlings, fledglings, immatures and/or adults: swallow-tailed kite (Elanoides forficatus),[242] Mississippi kite (Ictinia mississippiensis),[243] white-tailed kite (Elanus leucurus),[244] northern harrier (Circus hudsonius),[86] sharp-shinned hawk (Accipiter striatus),[245] Cooper's hawk (Accipiter cooperii),[246] goshawks,[226] gray hawk (Buteo plagiatus),[247] red-shouldered hawk[248] and broad-winged hawk (Buteo platypterus).[249] These species range from the 135.7 g (4.79 oz) sharp-shinned hawk, the smallest North American accipitrid, to the goshawk, which at 956 g (2.108 lb) is nearly red-tailed hawk sized.[226] Additionally, there are records of red-tailed hawks hunting 9 species of owl, ranging in size from the 104.2 g (3.68 oz) northern saw-whet owl (Aegolius acadius) to juveniles of the 1,079 g (2.379 lb) great gray owl (Strix nebulosa) and seemingly adults of the 717 g (1.581 lb) barred owl (Strix varia).[85][86] Red-tails will also hunt falcons including adult American kestrels (Falco sparverius) and merlins (Falco columbarius) and presumed nestlings of the peregrine falcon (Falco peregrinus).[86][250][251] When hunting other raptorial birds, red-tailed hawks seem to ambush them from a perch, diving suddenly and unexpectedly upon spotting the quarry and tend to have the greatest success when the raptorial prey is distracted, such as those migrating on windy days, feeding on their own prey and tending to their nest.[5][226][250]
In turn, red-tailed hawks may engage in behavior that straddles territorial exclusion and anti-predator behavior to the two much larger raptors in North America which actively hunt, the eagles. Red-tails are most commonly seen flying towards and aggressively displacing both flying bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos), but may also, to the contrary, unobtrusively duck down out of flight to an inconspicuous perch when an eagle is spotted. The behavioral variation is probably related to the activity of hawks, which may feel the need to protect their nests and food resources while actively breeding but are not usually willing to risk their lives in attacking an eagle while migrating or wintering. At times mobbing behavior of smaller raptors may cause both eagles to turn over and present their large talons to their attacker, which can be dangerous for the smaller hawk.[5][118][206][252] Besides the great horned owl, the two eagle species are the only known animals known to regularly threaten red-tailed hawks of any age. In particular, the golden eagle is probably the greatest daytime threat to fledged immature and adult red-tails, as these have turned up in many dietary studies of the powerful eagle.[85][253] Less efficient as a predator of red-tails, bald eagles nonetheless have been recording killing adults in some cases or, more often, depredating red-tailed hawk nests. On occasion, this may result in the bald eagle bringing the nestling red-tails to their own nest and, for some reason, not killing them. In some cases, the bald eagles inadvertently actually raise the nestling red-tails themselves and the baby red-tailed hawks may successfully fledge.[254] In one case, a red-tailed hawk was observed to kill a bald eagle chick, whether this was predatory or competitive, it quickly abandoned the dead nestling after the eagle’s parents returned.[255] On several tropical islands, which are often shared only with other hawks, owls and falcons of only medium or small size and typically lack larger raptors or carnivorans, the red-tailed hawk may be the largest native predator and will, in these cases, be considered the apex predator.[256][257] Other than large birds of prey, extensive records of predation on red-tailed hawks is surprisingly poor, in spite of several populations recording nestlings and eggs disappearing through presumed acts of natural predation. The most likely major predator of eggs and nestlings that disappear is the raccoon which, during its nocturnal foraging, is a notorious enemy of nearly any kind of birds nest.[5][4][258] It is also known that unidentified large snakes, probably consisting of the same species that the red-tails so readily predate during broad daylight, will prey upon nestling red-tails.[259] In California, common ravens were recorded preying on the downy young of red-tailed hawks.[260] Other corvids, including blue jays (Cyanocitta cristata), California scrub jays (Aphelocoma californica) and crows, are known to feed on eggs and small nestlings either when nest attendance is atypically low by the hawks or when they can successful harass the parent hawks via mobbing so severely that they temporarily leave the nest.[4][27][261] Blackflies (Simulium canonicolum) have been recorded as killing several red-tail chicks through blood loss.[262] There are also several cases of possible prey turning the tables on red-tailed hawks and either maiming or killing them. This is especially true of snakes, with some prey species of Pituophis, Pantherophis and Coluber known to overpower and nearly kill, often the hawk survives only if by human intervention. Not infrequently prey such as coral snakes and rattlesnakes may succeed in killing red-tailed hawks with their venom, even if they themselves are also killed and partially consumed.[118][186][263][264] Peregrine falcons are also known to kill red-tailed hawks that have come too close to their nests by stooping upon them.[5]
Pairs either court for the first time or engage in courtship rituals to strengthen pre-existing pair bonds before going into the breeding. The breeding season usually begins in late February through March, but can commence as early as late December in Arizona and late January in Wisconsin or to the opposite extreme as late as mid-April as in Alberta.[9][84][124][217] In this pre-nesting period, high-circling with much calling will occur. One or both members of a pair may be involved. The courtship display often involves dangling legs, at times the pair will touching each other's wings and male's feet may touch female's back, she may occasionally roll over and present talons. Food passes are rarely reported.[2][9][77] High soaring occurs aseasonally. Circling above territory tends to be done noisily and conspicuously, helping insure against possible takeovers. Spring circling of a pair can be a prelude to copulation.[27] A typical sky-dance involves the male hawk climbing high in flight with deep, exaggerated beats and then diving precipitously on half-closed wings at great speed, checking, and shooting back up, or often plunging less steeply and repeating process in a full rollercoaster across the sky. Sky-dances are done on periphery of the pair’s territory and it appears to designate the territory limits, occasionally one male’s sky-dance may also trigger a sky-dance by a neighboring male, who may even run a parallel course in the sky. Sky-dances no longer occur after late incubation.[2][5][65] Boundary flight displays may be engaged in by all four birds of 2 adjacent pairs.[27] Cartwheeling with interlocking talons is also seen occasionally in spring, almost always a territorial male expelling an intruding one, the latter often being a second or third year male that is newly mature. A perched display, with fluffed-out breast feathers may too occur at this time. Even males that are in spring migration have been recorded engaging in a separate display: circling at slow speed before partially closing wings, dropping legs with talons spread and tilting from side-to-side. A female hawk is usually around when migrating male does this but she does not engage in this display herself.[2][5] The area of occupancy of breeding territories by pairs is variable based on regional habitat composition. The highest recorded density of pairs was in California where each pair occurred on 1.3 km2 (0.50 sq mi), which was actually just ahead of Puerto Rico where pair occupancy averaged 1.56 km2 (0.60 sq mi) in peak habitat. The largest known average territory sizes were surprisingly in Ohio, where the average area of occupancy by pairs was recorded as 50 km2 (19 sq mi).[9][100][118] In Wisconsin mean ranges for males range from 1.17 to 3.9 km2 (0.45 to 1.51 sq mi) in males and from 0.85 to 1.67 km2 (0.33 to 0.64 sq mi) in females, respectively in summer and winter. Here and elsewhere, both members of the pair stay quite close together throughout winter if they are sedentary. On the other hand, migrant populations tend to separate while migrating and return to the same territory to find its prior mate, sometimes before they reach their home range.[9][100][235] In Alaska, returning migrant pairs were able to displace lone red-tailed hawks that had stayed on residence, especially lone males but sometimes even lone females.[77] In general, the red-tailed hawk will only take a new mate when its original mate dies.[265] Although pairs often mate for life, replacement of mates can often be quite fast for this common bird species. In one case in Baja California, when a female was shot on 16 May, the male of that pair was seen to have selected a new mate the following day.[5][266] In copulation, the female, when perched, tilts forward, allowing the male to land with his feet lodged on her horizontal back. The female twists and moves her tail feathers to one side, while the mounted male twists his cloacal opening around the female's cloaca. Copulation lasts 5 to 10 seconds and during pre-nesting courtship in late winter or early spring can occur numerous times each day.[267]
The pair constructs a stick nest most often in a large tree 4 to 21 m (13 to 69 ft) off the ground. They may too nest on virtually any man-made structures with some variety of ample ledges or surface space and good views of the surrounding environment (i.e. powerline poles, radio transmission towers, skyscraper buildings).[9][5][62][268][269][270] Much variation is recorded in nest usage behavior, many red-tails build new nests every year despite prior nests sometimes being in good standing and unoccupied, some may reuse a nest in subsequent years or may leave a nest for a year and then come back to it the following year.[9][5] A red-tailed hawk nest is typically located in a gradient zone between woods with tall, mature trees, if available, and openings whether this is composed of shrubland, grassland or agricultural areas.[271] Nest sites vary greatly in topography and vegetative composition.[272] While tree nests are largely preferred, occasionally they nest on cliff ledges may be utilized even where other nest sites are presumably available. Cliff nests may be located at 35 m (115 ft) or higher above the nearest flat ground.[5][273][274] At times, unlike great horned owls, red-tailed hawks have been recorded nesting in surprisingly unbroken forests.[275] In North Dakota, nest sites tend to be concentrated along wooded river drainages.[276] Compared to Swainson's hawks and ferruginous hawks, red-tailed hawk nests are usually in taller trees and are closer to waterways.[8][277] In Puerto Rico, nests are most often found in transitional zone between dry lowlands and mountainous cloud forests, with trees typically taller than their neighbors to allow views of more than half of their home ranges. More than 21 tree species were recorded used in Puerto Rico.[100] Tree species is seemingly unimportant to red-tailed hawks.[278] In some parts of Arizona, saguaro cactus were used exclusively as nesting sites.[217] Alternately, old nests of other Buteo hawks, corvids, golden eagles and even leaf nests of tree squirrels have also been used by red-tailed hawks.[2] Both members of the pair will build the nests but the female spends more time forming the bowl, with the greatest activity often in the morning and nest building completed in a week or less.[84][118] The nest is generally 71 to 97 cm (28 to 38 in) in diameter, with a mean of roughly 76 cm (30 in), and can be up to 96 cm (38 in) tall after several years use. The inner bowl averages about 37 cm (15 in) wide and 13 cm (5.1 in) deep.[9][65][235] The nest is constructed of twigs, and lined with bark, pine needles, corn cobs, husks, stalks, aspen catkins, or other plant lining matter. Lining the nest may be for warning other red-tails of the active use of a nest.[9][84] In moderate to northern climes, red-tailed hawks tend to face to the south or west, presumably to make them less vulnerable to strong northeasterly storm winds.[279]
In most of the interior contiguous United States the first egg is laid between mid-March and early April, ranging from 3 to 5 weeks after the nest is constructed, with the clutch completed 2 to 5 days after the initial egg is laid.[9][280] The average date of the laying the first egg can be variable: peaking mid-January in Puerto Rico, averaging 9 March in Arizona, 26 March in the Front Range Urban Corridor and 1 May in Alberta.[9][100][124][217] The mean initiation of clutches may bump weeks later if 10 cm (3.9 in) or more of snow is still on the ground in Wisconsin during March.[84] A clutch of one to three eggs is laid in March or April, depending upon latitude, with four eggs being uncommon and five and perhaps even six increasingly rare.[65] Clutch size depends almost exclusively on the availability of prey for the adults. At the species level, body size also determines clutch size. For example, while the total clutch weighs up to 18% of the females weight and the clutch size averages 2 to 3, a larger raptor like the golden eagle lays a smaller clutch, usually not more than two, that weighs less than 10% in total of the female’s body mass, whereas a smaller raptor like the kestrel lays a larger clutch averaging five that weighs 50% of the females weight.[4] Average clutch size vary from 1.96 in Alaska when prey populations were low up to 2.96 in Washington.[77][281] Eggs are laid approximately every other day. Average egg sizes in height and width (each with a sample size of 20) are in the following subspecies- B. j. borealis: 59.53 mm × 47.49 mm (2.344 in × 1.870 in); B. j. calurus: 60.04 mm × 47.1 mm (2.364 in × 1.854 in); B. j. fuertesi: 59.42 mm × 46.99 mm (2.339 in × 1.850 in).[282] The eggs of red-tailed hawks are mostly white, sometimes with a faint buffy wash; at times the eggs manifest a sparsely or heavily marked with blotches of buff, pale reddish-brown, dark brown, or purple. The markings often appear indistinctly and may combine to form a fine speckling.[283] They are incubated primarily by the female, with the male substituting when she leaves to hunt or merely stretch her wings. Rarely do the males incubate more than four hours of daylight. The male brings most food to the female while she incubates.[9][65][235][260]
After 28 to 35 days of incubation (averaging about three days longer in the Caribbean as does fledgling as compared to North American red-tails), the eggs hatch over 2 to 4 days.[2][284] Like most raptorial birds, the nestlings are altricial and nidicolous at hatching.[9][118] Hatchlings average 58 g (2.0 oz) in body mass with no difference in sizes of the sexes until the young are about 29 days old for mass and 21 days or so for external linear standard measurements such as bill and talon size.[285] The female broods them while the male provides most of the food to the female and the young, which are also known as eyasses (pronounced "EYE-ess-ez"). The female feeds the eyasses after tearing the food into small pieces. The young red-tails are active by the second day when they issue soft peeping calls, bounce, and wave continuously with their wings. By day 7, the bouncing and peeping begin to wane, and young start to peck at prey in their nest. Nestlings emit high whistling notes (usually in response to adults overhead) by day 10, sit up on tarsometatarsi by day 15, become aggressive toward intruders by day 16, strike out with talons and wings by day 21, begin to stretch wings and exercise regularly by day 30. After 42 to 46 days, the eyasses begin to leave the nest and tear apart prey for themselves.[9][118] The amount of food brought to the nest daily varies considerably, based on brood size and prey availability. In Alberta, an average of 410 to 730 g (14 to 26 oz) is brought each day for 1 to 3 nestlings while in Washington, it was estimated a minimum of 520 g (1.15 lb) per day for 1 surviving nestling and in Wisconsin, an estimated 219 g (7.7 oz) was needed for 1 nestling and 313 g (11.0 oz) for 2.[235][231][286] Brooding is strenuous for parent red-tails and both members of the pair usually lose some weight, especially the female. Some females may lose over 100 g (3.5 oz) between hatching and fledging.[9] During brooding the female may become aggressive to intruders, including humans. In the east, red-tailed hawk females rarely defend nests from humans but historically in California and quite often still in Alaska, some female will dive repeatedly and "savagely", sometimes snapping off large branches in her temper, occasionally stunning herself or inadvertently knocking down her own youngster if it is attempting to fledge. Apparently, the less extensive prior exposure they have to humans may make mature females more aggressive towards humans near the nest.[5][27][77] Although development is asynchronical in most nests, runting may sometimes be recorded and even siblicide may occur, with the parents feeding the weaker, younger chicks less so and both the siblings and parents occasionally aggressively pecking the "runts" of the nest. Ultimately, the runt in such cases does not usually survive and may be either found crushed in the nest, discarded out of the nest after starvation or consumed by the parents or the siblings. However, as a whole, such killings are fairly rare and only occur when food supplies are extremely low, often this being in sync with poor spring weather (such as overly rainy or cold conditions).[5][236][286] If there is too much food, such as California ground squirrels in California, the parents will discard remains after a day or two since decomposition of their prey invites infection, other diseases and blood-sucking insects to the nest that may endanger the nestlings. However, after about four weeks, the female often stops discarding leftover prey and the increased presence of flies may form somewhat of a risk to disease in the young but may also merely get the young to leave the nest sooner.[27][118] One nest in California had two females and one male attended to; the male performed his usual function but both females would brood and tend to the nest.[287] Additionally, bald eagles have been recorded to occasionally adopt red-tail fledglings into their nests. As recorded in Shoal Harbor Migratory Bird Sanctuary located near Sydney, British Columbia, on 9 June 2017, a juvenile red-tailed hawk was taken by a pair of bald eagles back to their nest, whereupon the chick, originally taken as prey, was accepted into the family by both the parents and the eagles' three fledglings. After surviving six weeks amongst the eagles, the fledgling, nicknamed "Spunky" by birdwatchers, had successfully begun learning to hunt and fly, showing that the aggressive hawk was able to survive amongst a nest of much larger adoptive siblings.[288][289]
Young typically leave the nest for the first time and attempt their first flights at about 42–46 days after hatching but usually they stay very near the nest for the first few days. During this period, the fledglings remain fairly sedentary, though they may chase parents and beg for food. Parents deliver food directly or, more commonly, drop it near the young. Short flights are typically undertaken for the first 3 weeks after fledgling and the young red-tails activity level often doubles. About 6 to 7 weeks after fledging, the young begin to capture their own prey, which often consists of insects and frogs that the young hawks can drop down to onto the ground with relative ease. At the point they are 15 weeks old, they may start attempts to hunt more difficult mammal and bird prey in sync with their newly developed skills for sustained flight, and most are efficient mammal predators fairly soon after their first attempts at such prey. Shortly thereafter, when the young are around 4 months of age, they become independent of their parents. In some extreme cases, juvenile red-tails may prolong their association with their parents to as long as they are half a year old, as was recorded in Wisconsin.[235][4][290][291] After dispersing from the parental territory, juveniles from several nests may congregate and interact in a juvenile staging area. Although post-fledgling siblings in their parents care are fairly social, they are rarely seen together post distribution from their parents range.[9][292] Usually, newly independent young hawks leave the breeding area and migrate, if necessary, earlier than adults do, however the opposite was true in the extreme north of Alaska, where adults were recorded to leave first.[292][293] Immature hawks in migratory populations tend to distribute further in winter than adults from these populations do.[294] Immatures attempting to settle for the winter often are harassed from territory to territory by older red-tails, settling only in small, marginal areas. In some cases, such as near urban regions, immatures may be driven to a small pockets of urban vegetation with less tree cover and limited food resources. When a distant adult appears, immatures may drop from a prominent perch to a more concealed one.[27][84] In some cases, hungry immature red-tails have been recorded making attempts at hunting prey beyond their capacities, expending valuable energy, such as healthy adults of larger carnivorans such as coyotes (Canis latrans), foxes and badgers and healthy flying passerines.[5] There are some cases of red-tailed hawks, presumably younger than two years of age, attempting to breed, often with an adult bird of the opposite sex. Such cases have been recorded in Alberta, Arizona and Wisconsin, with about half of these attempts being successful at producing young.[124][162][281][295] However, while adult plumage and technically sexual maturity is attained at two years old, many red-tails do not first successfully breed until they are around 3 years of age.[9]
Breeding success is variable due to many factors. Estimated nesting success usually falls between 58% and 93%.[217][236] Nesting success rates are probably drive primarily by prey populations, regional habitat composition, competition levels with other red-tailed hawks, predation rates (often due to great horned owls or perhaps raccoons) and human disturbance levels.[5][9][4] In Oregon specifically, nesting success varied primarily based on "dispersion and density of perches" secondarily to ground squirrel abundance and whether the nest of other pairs red-tails was directly visible from a nest.[206][296] Repeated disturbances at the nest early in the nesting cycle may cause abandonment of eggs or nestlings in some cases, but seemingly pairs are less likely to abandon the young later in the season in cases of human disturbance.[5] 30% of nesting deaths in a study from Wisconsin were from nestlings falling to their death or the nest collapsing.[235] In Puerto Rico, habitat appeared to be the primary driver of breeding success, as in lowland pastures nesting success was 43% producing a mean number of fledglings of 1.5 whereas in cloud forest success was 34% producing a mean of 0.7 fledglings.[100] A modelling study in Puerto Rico showed that, apart from adult survival, nestling survival had the second greatest influence on population growth.[297] In Wyoming, 12 pairs on a 12 square mile tract produced an average of 1.4 young per pair.[27] In comparison, the mean number of fledglings was 0.96 in Michigan, 1.36 in Montana and was 1.4 in the Appalachians.[39][290][298] In Wisconsin, the number of young successfully to fledge ranged from 1.1 to 1.8 from year to year probably depending on staple prey numbers.[84] The record lifespan in wild for a red-tailed hawk is 25 years and 5 months from banding studies. In comparison, lifespans of up to 29.5 years have been recorded in captivity.[5] In the wild, other red-tailed hawks have lived for at least 25 years, for example, Pale Male was born in 1990, and in Spring 2014 was still raising eyasses.[62] However, of 5195 banded wild red-tailed hawks in one bander’s recordings, only 31 were reported to have survived to 17 years of age and only 11 survived for 20 years.[299] The average mortality rate at 1 year of age for red-tails is 54% and thereafter is around 20% from banding sources.[281] The estimated average lifespan of red-tailed hawks who attain maturity, per Palmer (1988), was claimed as only 6 to 7 years.[5] The main causes of mortality considered as electrocution on power lines, other collisions, shooting, consumption of poisoned baits set for other animals and collision with vehicles and other crafts. While most mortality of young red-tails is at least mainly due to natural causes, mortality of fledged or older red-tails is now mostly attributable to human killing, accidental or intentional, as well as flying into manmade materials.[2][260][300] Hawks in urban areas are threatened by the use of rat traps and poisoned bait to kill rodents. This generally consists of warfarin cookies which induce internal bleeding in rats and mice, and a hawk that ingests rodents who have consumed rat poison can itself be affected.[301] Red-tailed hawks are also vulnerable to fatal bacterial infections include peritonitis, myocarditis, granulamotous, sarcocystosis and mycobateriosis as well as some forms of viral infection, to which immature hawks especially, as they often have less access to coverage in poor weather conditions, are most vulnerable.[9] Neither this nor other Buteo hawks were found to be highly susceptible to long-term DDT egg-shell thinning due to being part, generally, of relatively short, terrestrial-based food chains.[4]
The red-tailed hawk is a popular bird in falconry, particularly in the United States where the sport of falconry is tightly regulated; this type of hawk is widely available and is frequently assigned to apprentice falconers.[302] Red-tailed hawks are highly tameable and trainable, with a more social disposition than all other falcons or hawks other than the Harris's hawk.[303] They are also long lived and fairly disease resistant, allowing a falconer to maintain a red-tailed hawk as a hunting companion for potentially up to two decades.[10] There are fewer than 5,000 falconers in the United States, so despite their popularity any effect on the red-tailed hawk population, estimated to be about one million in the United States, is negligible.[304]
Not being as swift as falcons or accipiters, red-tailed hawks are usually used to hunt small game such as rabbits and squirrels, as well as larger quarry such as Hares. However, some individuals may learn to ambush game birds on the ground before they are able to take off and accelerate to full speed, or as they have fly into cover after a chase. Some have even learned to use a falcon-like diving stoop to capture challenging game birds such as pheasants in open country.
In the course of a typical hunt, a falconer using a red-tailed hawk most commonly releases the hawk and allows it to perch in a tree or other high vantage point. The falconer, who may be aided by a dog, then attempts to flush prey by stirring up ground cover. A well-trained red-tailed hawk will follow the falconer and dog, realizing that their activities produce opportunities to catch game. Once a raptor catches game, it does not bring it back to the falconer. Instead, the falconer must locate the bird and its captured prey, "make in" (carefully approach) and trade the bird off its kill in exchange for a piece of offered meat.[10][305]
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A trained red-tailed hawk working with a volunteer from the Ojai Raptor Center
A falconer's red-tailed hawk comes in for a landing
The feathers and other parts of the red-tailed hawk are considered sacred to many indigenous people and, like the feathers of the bald eagle and golden eagle, are sometimes used in religious ceremonies and found adorning the regalia of many Native Americans in the United States; these parts, most especially their distinctive tail feathers, are a popular item in the Native American community.[306] As with the other two species, the feathers and parts of the red-tailed hawk are regulated by the eagle feather law,[307] which governs the possession of feathers and parts of migratory birds.[308]
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{{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) The red-tailed hawk (Buteo jamaicensis) is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members within the genus of Buteo in North America or worldwide. The red-tailed hawk is one of three species colloquially known in the United States as the "chickenhawk", though it rarely preys on standard-sized chickens. The bird is sometimes also referred to as the red-tail for short, when the meaning is clear in context. Red-tailed hawks can acclimate to all the biomes within their range, occurring on the edges of non-ideal habitats such as dense forests and sandy deserts. The red-tailed hawk occupies a wide range of habitats and altitudes, including deserts, grasslands (from small meadows to the treed fringes of more extensive prairies), coniferous and deciduous forests, agricultural fields, and urban areas. Its latitudinal limits fall around the tree line in the subarctic and it is absent from the high Arctic. Generally it favors varied habitats with open woodland, woodland edge and open terrain. It is legally protected in Canada, Mexico, and the United States by the Migratory Bird Treaty Act.
The vary in appearance and range, varying most often in color, and in the west of North America, red-tails are particularly often strongly polymorphic, with individuals ranging from almost white to nearly all black. The subspecies Harlan's hawk (B. j. harlani) is sometimes considered a separate species (B. harlani). The red-tailed hawk is one of the largest members of the genus Buteo, typically weighing from 690 to 1,600 g (1.5 to 3.5 lb) and measuring 45–65 cm (18–26 in) in length, with a wingspan from 110–141 cm (3 ft 7 in – 4 ft 8 in). This species displays sexual dimorphism in size, with females averaging about 25% heavier than males.
The diet of red-tailed hawks is highly variable and reflects their status as opportunistic generalists, but in North America, they are most often predators of small mammals such as rodents of an immense diversity of families and species. Prey that is terrestrial and at least partially diurnal is preferred, so types such as ground squirrels are preferred where they naturally occur. Over much of the range, smallish rodents such as voles alternated with larger rabbits and hares often collectively form the bulk of the diet. Large numbers of birds and reptiles can occur in the diet in several areas, and can even be the primary foods. Meanwhile, amphibians, fish and invertebrates can seem rare in the hawk’s regular diet, but they are not infrequently taken by immature hawks. Red-tailed hawks may survive on islands absent of native mammals on diets variously including invertebrates such as crabs, as well as lizards or birds. Like many Buteo species, they hunt from a perch most often, but can vary their hunting techniques where prey and habitat demand it. Because they are so common and easily trained as capable hunters, in the United States they are the most commonly captured hawks for falconry. Falconers are permitted to take only passage hawks (which have left the nest, are on their own, but are less than a year old) so as to not affect the breeding population. Passage red-tailed hawks are also preferred by falconers because they have not yet developed the adult behaviors that would make them more difficult to train.
La Jamajka buteo (Buteo jamaicensis laŭ la scienca nomo) aŭ pli populare ruĝvosta buteo (Buteo jamaicensis) estas mezgranda al granda rabobirdo de la familio de Akcipitredoj, kiu estas unu el tri specioj populare konataj en Usono kiel "chickenhawk", nome kokagloj, kvankam ĝi rare predas standardgrandajn kokojn.[1] Ĝi reproduktiĝas tra plej de Nordameriko, el okcidenta Alasko kaj norda Kanado ĝis tiom suden kiom ĝis Panamo kaj Karibio, kaj estas unu el la plej komunaj buteoj de Nordameriko. La Ruĝvostaj buteoj povas alkutimiĝi al ĉiuj klimataj biomoj ene de sia teritorio. Estas 14 agnoskataj subspecioj, kiuj varias laŭ aspektoj kaj teritorioj. Ĝi estas unu el la plej grandaj membroj de la genro Buteo en Nordameriko, tipe peza el 690 al 1600 g kaj 45–65 cm longa kun enverguro de 110 al 145 cm. La Ruĝvostaj buteoj estas kazo de seksa dimorfismo laŭgrande, ĉar inoj averaĝas ĉirkaŭ 25 % pli fortikaj ol maskloj.
La Harlana buteo (B. j. harlani), ofte konsiderata separata specio, estas traktata sube en la apartaĵo pri Taksonomio.
La Jamajka buteo okupas ampleksan gamon de habitatoj kaj altitudoj, inklude dezertojn, herbejojn, arbarojn de koniferoj kaj deciduaj, tropikajn pluvarbarojn, terkulturejojn kaj urbajn areojn. Ĝi loĝas tra la tuta Nordamerika kontinento, escepte en areoj senarbaraj de pleja Arkto. Ĝi estas laŭleĝe protejtata en Kanado, Meksiko kaj Usono per la Traktato de Migrantaj Birdoj de 1918.
Ĉar ili estas tiom komunaj kaj facile trejneblaj kiel kapablaj ĉasistoj, la majoritato de buteoj kaptataj por falkado en Usono estas Jamajkaj buteoj. Falkadistoj rajtas kapti nur migrantajn buteojn (kiuj jam estis forlasinta la neston, vivas propran vivon, sed estas malpli de unujaraĝaj) por ne malbonigi la reproduktan populacion. Plenkreskuloj, kiuj povus esti reproduktantaj aŭ idozorgantaj, ne povas esti prenataj por falkadaj celoj kaj estas kontraŭleĝa fari tion. Pasintaj ruĝvostaj buteoj kongrue estas preferataj de falkadistoj ĉar tiuj junuloj ankoraŭ ne disvolvigis plenkreskulan kutimaron, kaj povas esti trejnitaj esence pli efike.
La Jamajka buteo ankaŭ gravas por la kulturo de indianoj. Ties plumoj estas konsiderataj sakraj fare de kelkaj triboj, kaj estas uzataj en religiaj ceremonioj.
Masklo de Jamajka buteo povas pezi el 690 al 1300 g kaj estas 45–56 cm longa, la ino povas pezi el 900 al 2000 g kaj esti 48 al 65 cm longa; enverguro estas ĉirkaŭ 114 al 133 cm. Kiel ĉe multaj rabobirdoj la Jamajka buteo estas kazo de seksa dimorfismo laŭgrande, ĉar inoj estas ĝis 25 % pli grandaj ol maskloj.[2]
La plumaro de la Jamajka buteo povas esti varia, depende el la subspecio kaj el la regiono. Tiuj kolorvarioj estas morfoj, kaj ne rilatas al plumoŝanĝado. La okcidenta nordamerika populacio, B. j. calurus, estas la plej varia subspecio kaj havas tri kolormorfojn: hela, malhela kaj intermeza aŭ ruĝeca. La malhela kaj intermezaj morfoj konsistigas 10–20% el la populacio.[3]
Kvankam markoj kaj nuancoj varias, la baza aspekto de la Jamajka buteo estas konsista. La suba ventro estas pli hela ol la dorso kaj malhelbruna bendo trapasas la ventron, formata per vertikalaj strioj en la plumarbildo, kaj ekzistas en plej kolorvarioj. La ruĝeca vosto, kio havigas unu el la du plej uzatajn komunajn nomojn, estas uniforme brikoruĝa supre kaj rozkoloreca sube.[4] La beko estas mallonga kaj malhela, kun la hoka formo karaktera de rabobirdoj. Ili havas mallongajn larĝajn vostojn kaj dikajn fortikajn flugilojn.[4] La vaksaĵoj, kruroj, kaj piedoj de la Ruĝvostaj buteoj estas flavaj.[2]
Nematuruloj povas esti facile idengitaj de proksime pro siaj flavecaj irisoj. Ĉar tiuj birdoj atingas plenan maturecon post ĉirkaŭ 3–4 jaroj, la irisoj malrapide malheliĝas al ruĝecbruna nuanco. Kaj ĉe la hela kaj ĉe la malhela morfoj, la vosto de la nematurulo de Jamajka buteo havas bildon kun nombraj malhelaj strioj.[4]
La Jamajka buteo estas membro de la genro Buteo, grupo de mezgrandaj rabobirdoj kun fortikaj korpoj kaj larĝaj flugiloj. Membroj de tiu genro estas konataj kiel buteoj en Eŭropo, sed kiel akcipitroj en Nordameriko.[5]
Estas almenaŭ 14 agnoskataj subspecioj de Buteo jamaicensis, kiuj varias laŭ teritorioj kaj koloroj:
La kvar insulformoj nome jamaicensis, solitudinus, socorroensis, kaj fumosus, ne koincidas en teritorioj kun iu ajn el la aliaj subspecioj.
La Jamajka buteo estas unu el la plej amplekse distribuataj buteoj de Ameriko. Ĝi reproduktiĝas el centra Alasko, Jukono, kaj la Nordokcidentaj Teritorioj orienten al suda Kebekio kaj la Marprovincoj de Kanado, kaj suden al Florido, Karibio, kaj Centrameriko. La vintraj teritorioj etendas el suda Kanado suden tra la restoj de la reprodukta teritorio.[6]
Ties preferata habitato estas miksita arbaro kaj kamparo, kun altaj arbetoj aŭ arboj, kiuj povas esti uzataj kiel ripozejoj (gvatejoj). Ĝi okupas ampleksan gamon de habitatoj kaj altitudoj, inklude dezertojn, herbejojn, marbordajn regionojn, montarojn, deklivarojn de montaj arbaroj de koniferoj kaj deciduaj, tropikajn pluvarbarojn, terkultivejojn kaj ĉeurbajn areojn.[8] Ĝi estas la dua plej adaptema post la Migra falko al uzado de diversaj habitatoj en Nordameriko.[9] Ĝi loĝas tra la Nordamerika kontinento, escepte ĉe areoj nearbaraj en alta Arkto.[3]
La Jamajka buteo estas disvastigata en Nordameriko,[9] parte pro historiaj setlomodeloj, el kiuj ĝi profitis. Arbarklarigado en Nordoriento kreis ĉasareojn, dum la konservado de arbareroj lasis nestolokojn. La plantado de arboj en okcidento permesis la Jamajkan buteon etendi siajn teritoriojn per kreado de nestolokoj kie iam estis neniu. La konstruado de senarbaj aŭtoŝoseoj kaj laŭlonge de ili instalado de fostoj havigis perfektan habitaton por ripozĉasado. La Jamajka buteo povas troviĝi ankaŭ ĉe urboj.[10]
Dumfluge tiu rabobirdo ŝvebas havante siajn flugilojn laŭ ioma duedra angulo, flugilfrapante tiom malmulte kiom eblas por ne elspezi energion. Aktiva flugado estas malrapida kaj certa, kun neprofunda flugilfrapado. Dum vento, ĝi foje ŝvebas per flugilfrapado kaj restas senmove supergrunde.[3] Dum ŝvebado aŭ flugilfrapado, ĝi tipe veturas je 64 km/h, sed dum falflugo ĝi povas superi 190 km/h.[11]
La krio de la Jamajka buteo estas 2 aŭ 3-sekunda raŭka, raspa krio, priskribata kiel krii-ii-ar,[10] kiu ekas altatone kaj descendas.[11] Tiu krio estis ofte priskribata kiel sono simila al tiu de vapora fajfo.[2] La Jamajka buteo ofte voĉas dum ĉasado aŭ ŝvebado, sed pli laŭte kaze de ĝenado aŭ kolero, responde al predanto aŭ al entrudo de rivala buteo ene de sia teritorio.[10] Deproksime ĝi faras raŭkan "gah-rank".[12] Junuloj povas krii ĝemajn klee-uk por peti manĝon kiam la gepatroj elnestiĝas.[13] La fiera akralaŭta krio de la Jamajka buteo estas ofte uzata kiel ĝenra rabobida sono en televida aŭ kina produktado, eĉ se la aperanta birdo tute ne estas Jamajka buteo.
La Jamajka buteo estas karnovora, kaj oportunema manĝanto. Ties dieto estas ĉefe malgrandaj mamuloj, sed ĝi inkludas ankaŭ birdojn kaj reptiliojn. Predoj varias laŭ regiona kaj sezona disponeblo, sed kutime centriĝas al roduloj, kiuj estas 85% el la butea dieto.[2] Plej komune konstatitaj predoj estas musoj, kampomusoj, tamiasoj, marmotini, sciuroj kaj marmotoj.[14][15] Aldonaj predoj (listataj laŭ descenda verŝajna predado) estas leporuloj, sorikoj, vespertoj, serpentoj, akvobirdoj, fiŝoj, krustuloj kaj insektoj. Predoj gamas laŭgrande el skaraboj al Blankavosta leporo, kiuj estas duoble la pezo de plej Jamajkaj buteoj. En kaptiveco vintre, averaĝa Jamajka buteo manĝas ĉirkaŭ 135 g tage.[13]
La Jamajka buteo ĉasas ĉefe el elstara ripozejo, flugofalante suben el gvatejo por kapti la predon, kaptas birdojn dumfluge, aŭ persekutas predon surgrunde per malalta flugo.
La Granda kornostrigo okupas similan ekologian niĉon noktule, kaj kaptas similajn predojn. Povas okazi konkurenco inter la Jamajka buteo kaj la Granda kornostrigo dum krepusko, kvankam la diferencaj reprodukta sezono kaj aktiveca tempo kutime rezultas en manko de rekta konkurenco.[16] Kvankam la predo de la Jamajka buteo estas averaĝe pli granda (parte pro malabundo de tagaj sciuroj en la kornostriga dieto),[15] la Granda kornostrigo estas foje predanto de la Jamajkaj buteoj kaj ties nestoj.[14] Aliaj konkurencantoj estas aliaj grandaj membroj de la gerno Buteo kiaj la Svainsona buteo kaj la Vilkrura buteo same kiel la Akcipitro, ĉar predoj kaj manĝoteknikoj de tiuj specioj foje koincidas.[17][18] Oni observis tiujn buteojn sekvante taksideojn por kapti predojn forfuĝintajn kaj ambaŭ estas konsiderataj eventualaj konkurencantoj.[19] Konkurenco ĉe kadavraĵoj povas okazi kun la Larĝbeka korvo kiam kelkaj korvoj kunlaboras por forpeli buteon.[20] Pli grandaj rabobirdoj, kiaj agloj aŭ la Reĝa buteo, povas rabi la buteajn predojn.[2]
La Jamajka buteo atingas staton de seksa matureco post du jaroj. Ĝi estas monogama, kaj pariĝas kun la sama individuo por multaj jaroj. Ĝenerale la Jamajka buteo prenos novan partneron nur kiam la origina partnero mortas.[21] La sama nestoteritorio povas esti defendata de la paro dum jaroj. Dum pariĝado masklo kaj ino flugas laŭ ampleksaj cirkloj kaj akre krias. La masklo plenumas aerajn ceremonian memmontrojn, subitajn plonĝojn, kaj reajn ascendojn. Post kelkaj ripetoj de tiu flugoceremonio, li foje tuŝas ŝin per kalkanumoj. Tio povas daŭri 10 minutojn aŭ plie. Kopulacio ofte sekvas pariĝan flugojn, kvankam foje kopulacio ofte okazas sen ceremoniaj flugoj.
Por kopulacio, la ino, ripoze, kliniĝas antaŭen, permesante la masklon surhalti per siaj piedoj sur ŝia horizontala dorso. La ino deflankiĝas sian voston, dum la masklo kunigas la kloakojn. Kopulacio daŭras 5 al 10 sekundoj kaj dum la antaŭnestado fine de vintro aŭ komence de printempo tio povas okazi nombrajn fojojn ĉiutage.[22]
En la sama periodo, la paro konstruas neston el bastoneteroj sur granda arbo 4 al 21 m supergrunde aŭ en klifokornico 35 m aŭ eĉ pli alte supergrunde, aŭ povas nestumi ankaŭ sur homfaraj strukturoj. La nesto estas ĝenerale 71 al 97 cm de diametro kaj povas esti ĝis 90 cm alta. La nesto estas konstruata el bastoneteroj kaj kovrata el arboŝeleroj, pinpingloj, spadikoj, ŝeloj, tigetoj, amentoj de tremolo aŭ alia kovra plantomaterialo.
La Granda kornostrigo konkurencas kun la Jamajka buteo por nestolokoj. Ambaŭ specioj mortigas la junulojn kaj detruas la ovojn de la alia, sed ĝenerale, ambaŭ specioj nestumas en apudaj aŭ koincidaj teritorioj sen konfliktoj. La Granda kornostrigo malkapablas konstrui nestojn kaj tipe elprenas jam ekzistantajn nestojn de Jamajka buteo. La Granda kornostrigo komencas la kutimaron de la reprodukta sezono multe pli frue ol la Jamajka buteo, ofte tiom frue kiom ĝis decembre. La Jamajka buteo estas adaptata al konstruo de novaj nestoj kiam pasintjara nesto estis prenita de kornostrigo aŭ iele perdita. Novaj nestoj estas tipe je 1 km aŭ malpli el la antaŭa nesto. Ofte nova nesto estas nur je kelkcentoj metroj aŭ malpli el pasintjara nesto. Ĉar ĝi estas granda predanto, plej predado farata al tiuj buteoj okazas al ovoj kaj idoj, kiuj estas prenataj de kornostrigoj, korvedoj kaj lavursoj.[23]
La ino demetas 1 al 3 ovojn marte al aprilo, depende el latitudo. Ovarkvanto dependas preskaŭ nur el disponeblo de predoj por plenkreskuloj. La ovoj estas demetataj proksimume ĉiun tagon. La ovoj estas kutime ĉirkaŭ 60 x 47 mm. Ili estos kovataj ĉefe fare de la ino, kaj la masklo anstataŭas ŝin kiam la ino foriras ĉasi aŭ nur por etendi siajn flugilojn. La masklo alportas plej manĝon por la ino dum ŝi kovantas. Post 28 al 35 tagoj, okazas eloviĝo dum ĉirkaŭ 2 al 4 tagoj; la idoj estas malfrumaturaj je eloviĝo. La ino plukovas ilin dum la masklo havigas plej manĝon al la ino kaj al la idoj, kies manĝon la ino disŝiras en malgrandaj eroj. Post 42 al 46 tagoj komencas elnestiĝo de la buteidoj per mallongaj flugoj. Tio daŭras ĝis 10 semajnoj, dum kiuj la buteidoj lernas flugi kaj ĉasi.[2]
La libro Red-Tails in Love: A Wildlife Drama in Central Park (Enamiĝintaj Ruĝvostaj buteoj: Natura Dramo en Centra Parko) de Marie Winn faris Pale Male, Ruĝvosta buteo de Novjorko, la plej fama urba Ruĝvosta buteo.[24]
La Jamajka buteo estas populara birdo en falkado, ĉefe en Usono kie la sporto de falkado estas strikte regulata je federaj kaj subŝtataj niveloj. Estas malpli da 5,000 falkadistoj en Usono, kiuj ne malbonigas la populacion de Ruĝvosta buteo, ĉirkaŭkalkulata je unu miliono en Usono.[25]
Por ĉasado falkadisto uzante Ruĝvostan buteon plej komune liberigas ĝin kaj permesas ĝin ekripozi sur gvatejo en arbo aŭ alia alta elstaraĵo. La falkadisto, foje kun helpo de hundo, klopodas ĉasteknikon per serĉo de predo surgrunde. Bone trejnita Ruĝvosta buteo sekvos la falkadiston kaj ties hundon, konstatinte ke ties aktivaĵoj produktas oportunojn kapti predon. Post kiam la rabobirdo kaptas ĉasaĵon, ĝi ne alportas ĝin al la falkadisto. Anstataŭ la falkadisto devas lokigi la birdon kaj ties kaptitan predon, zorge alproksimiĝi kaj ŝanĝi al la buteo la kaptaĵon kontraŭ peco de viando.[26] Surprize tiuj buteoj ne elsendas siajn klasikan krialvokon tre multe post kiam ili estis kaptitaj.
La plumoj kaj aliaj partoj de la Ruĝvosta buteo estas konsiderataj sakraj fare de multaj amerikaj indiĝenoj kaj kiel ĉe la plumoj de la Blankkapa maraglo kaj de la Reĝa aglo, estas foje uzataj en religiaj aŭ kulturaj ceremonioj kaj por ornami la ceremoniajn vestarojn de la usonaj indiĝenoj; tiuj partoj, ĉefe ties distingaj vostoplumoj, estas populara afero en la indiĝena usona komunumo.[27] Kiel ĉe la aliaj du specioj, ankaŭ la plumoj kaj partoj de la Ruĝvosta buteo estas regulataj de la aglopluma leĝo,[28] kiu regas pri posedo de plumoj kaj partoj de migrantaj birdoj.[29]
La Jamajka buteo (Buteo jamaicensis laŭ la scienca nomo) aŭ pli populare ruĝvosta buteo (Buteo jamaicensis) estas mezgranda al granda rabobirdo de la familio de Akcipitredoj, kiu estas unu el tri specioj populare konataj en Usono kiel "chickenhawk", nome kokagloj, kvankam ĝi rare predas standardgrandajn kokojn. Ĝi reproduktiĝas tra plej de Nordameriko, el okcidenta Alasko kaj norda Kanado ĝis tiom suden kiom ĝis Panamo kaj Karibio, kaj estas unu el la plej komunaj buteoj de Nordameriko. La Ruĝvostaj buteoj povas alkutimiĝi al ĉiuj klimataj biomoj ene de sia teritorio. Estas 14 agnoskataj subspecioj, kiuj varias laŭ aspektoj kaj teritorioj. Ĝi estas unu el la plej grandaj membroj de la genro Buteo en Nordameriko, tipe peza el 690 al 1600 g kaj 45–65 cm longa kun enverguro de 110 al 145 cm. La Ruĝvostaj buteoj estas kazo de seksa dimorfismo laŭgrande, ĉar inoj averaĝas ĉirkaŭ 25 % pli fortikaj ol maskloj.
La Harlana buteo (B. j. harlani), ofte konsiderata separata specio, estas traktata sube en la apartaĵo pri Taksonomio.
La Jamajka buteo okupas ampleksan gamon de habitatoj kaj altitudoj, inklude dezertojn, herbejojn, arbarojn de koniferoj kaj deciduaj, tropikajn pluvarbarojn, terkulturejojn kaj urbajn areojn. Ĝi loĝas tra la tuta Nordamerika kontinento, escepte en areoj senarbaraj de pleja Arkto. Ĝi estas laŭleĝe protejtata en Kanado, Meksiko kaj Usono per la Traktato de Migrantaj Birdoj de 1918.
Ĉar ili estas tiom komunaj kaj facile trejneblaj kiel kapablaj ĉasistoj, la majoritato de buteoj kaptataj por falkado en Usono estas Jamajkaj buteoj. Falkadistoj rajtas kapti nur migrantajn buteojn (kiuj jam estis forlasinta la neston, vivas propran vivon, sed estas malpli de unujaraĝaj) por ne malbonigi la reproduktan populacion. Plenkreskuloj, kiuj povus esti reproduktantaj aŭ idozorgantaj, ne povas esti prenataj por falkadaj celoj kaj estas kontraŭleĝa fari tion. Pasintaj ruĝvostaj buteoj kongrue estas preferataj de falkadistoj ĉar tiuj junuloj ankoraŭ ne disvolvigis plenkreskulan kutimaron, kaj povas esti trejnitaj esence pli efike.
La Jamajka buteo ankaŭ gravas por la kulturo de indianoj. Ties plumoj estas konsiderataj sakraj fare de kelkaj triboj, kaj estas uzataj en religiaj ceremonioj.
El ratonero de cola roja o busardo colirrojo[2] (Buteo jamaicensis), también conocido como gavilán de monte, gavilán colirrojo o aguililla cola roja (en la República Dominicana y en Puerto Rico, guaraguao o warawao), es una especie de ave rapaz de la familia Accipitridae, ampliamente distribuida desde Alaska hasta las Antillas. Es una de los Buteos más grandes alcanzando de 45 a 65 cm y hasta 1,6 kg de peso. De color variable según la subespecie. Vive en una amplia gama de hábitats y altitudes como desiertos, pastizales, bosques y hasta zonas urbanas. Está legalmente protegida en Canadá, México y EE. UU. por el Tratado de Aves Migratorias. En la Lista Roja de la IUCN se considera bajo preocupación menor (LC). Es una de las rapaces más abundantes y más utilizadas en la cetrería en Norteamérica.[3][4][5]
Se conocen 14 subespecies de Buteo jamaicensis:[6]
En El Yunque, Puerto Rico, se reporta la mayor densidad de estas aves en todo el mundo.[7]
Las variaciones entre las subespecies de Buteo jamaicensis, además de los diferentes híbridos naturales que se producen entre dichas subespecies y otros buteos, son considerables, resultando a veces muy difíciles de clasificar o reconocer por la variación de tamaño y de plumaje. El plumaje de juvenil y adulto es muy similar para todas las subespecies, aunque estos últimos suelen tener las alas más anchas y la cola más corta; las únicas variaciones importantes entre juveniles y adultos son el color de la cola (no es roja todavía) y la banda abdominal, que suele ser más marcada en los jóvenes que en los adultos de una misma subespecie.
Los machos y las hembras son similares en cuanto al plumaje.
El ratonero de cola roja recibe su nombre debido al color de la superficie superior de su cola, un tono que va desde un rojo anaranjado o incluso rosa pálido hasta un rojo intenso, y que aparece normalmente a partir del año de edad o segundo otoño con la primera muda, apreciándose en algunos casos completamente en la segunda muda. En la gran mayoría de ejemplares adultos, al final de su cola aparece una banda ancha y oscura de color negro. La superficie inferior de su cola es de un blanco intenso, que en algunos ejemplares llega a adquirir un color plateado.
Siendo una de las rapaces más abundantes en Estados Unidos, no es de extrañar que también sea una de las rapaces más empleadas en la cetrería, especialmente en Norteamérica y en el Reino Unido, tanto por principiantes como por conocidos maestros cetreros, además de ser utilizada frecuentemente en exhibiciones.
|url= incorrecta con autorreferencia (ayuda) (en inglés.). Consultado el 3 de marzo de 2020. El ratonero de cola roja o busardo colirrojo (Buteo jamaicensis), también conocido como gavilán de monte, gavilán colirrojo o aguililla cola roja (en la República Dominicana y en Puerto Rico, guaraguao o warawao), es una especie de ave rapaz de la familia Accipitridae, ampliamente distribuida desde Alaska hasta las Antillas. Es una de los Buteos más grandes alcanzando de 45 a 65 cm y hasta 1,6 kg de peso. De color variable según la subespecie. Vive en una amplia gama de hábitats y altitudes como desiertos, pastizales, bosques y hasta zonas urbanas. Está legalmente protegida en Canadá, México y EE. UU. por el Tratado de Aves Migratorias. En la Lista Roja de la IUCN se considera bajo preocupación menor (LC). Es una de las rapaces más abundantes y más utilizadas en la cetrería en Norteamérica.
Buteo jamaicensis Buteo generoko animalia da. Hegaztien barruko Accipitridae familian sailkatua dago.
Buteo jamaicensis Buteo generoko animalia da. Hegaztien barruko Accipitridae familian sailkatua dago.
Amerikanhiirihaukka (Buteo jamaicensis) on yleissävyltään ruosteenruskea petolintu, joka pesii miltei koko Pohjois-Amerikan alueella, länsi-Alaskasta ja pohjois-Kanadasta jopa Panamaan ja Karibian saarten alueelle asti. Se on yleisimpiä Pohjois-Amerikan hiirihaukkojen (buteo) sukuun kuuluvia haukkoja. Amerikanhiirihaukoista on tunnistettu 14 eri alalajia, joiden ulkonäkö ja levinneisyys vaihtelee. Se on myös kookkaimpia Pohjois-Amerikan Buteo-suvun haukkoja: amerikanhiirihaukka painaa noin 690–1 600 g, pituus on 45–65 cm ja siipien kärkiväli 110–145 cm.
Amerikanhiirihaukkoja kasvatetaan käytettäviksi haukkametsästyksessä. Koska laji on niin yleinen ja helposti koulutettavissa metsästystarkoituksiin, suurin osa haukkametsästykseen valituista linnuista Yhdysvalloissa on amerikanhiirihaukkoja. Haukkametsästyksen harrastajien on lupa ottaa käyttöön vain haukkoja, jotka ovat jättäneet pesänsä ja omillaan mutta ovat alle vuoden vanhoja, jotta pesimäpopulaatio ei vaarantuisi. Näitä haukkoja suositaan myös siksi, koska kyseisille nuoremmille linnuille ei ole kehittynyt täysikasvuisten käyttäytymistapoja, jotka tekisivät koulutuksesta huomattavasti haastavampaa. Pesiviä ja poikasia pitäviä täysikasvuisia amerikanhiirihaukkoja on laitonta ottaa metsästystarkoituksiin.
Amerikanhiirihaukka on yleissävyltään ruosteenruskea. Sen rinnan poikki kulkee tummempi raita, ja siiven alapinnalla on tumma kuvio. Eri osissa Pohjois-Amerikan mannerta on eri sävyisiä kantoja.
Sen pituus on 45–65 cm, siipien kärkiväli ja paino 800–1 300 grammaa. Naaras on suurempi kuin koiras.
Amerikanhiirihaukan pesimisalue ulottuu Alaskasta Panamaan.
Amerikanhiirihaukka on lihansyöjä ja ravinnonhankkijana opportunisti. Amerikanhiirihaukka syö pieniä nisäkkäitä, lintuja ja matelijoita. Tyypillisiä saaliseläimiä ovat jyrsijät, kaniinit, kanalinnut, käärmeet ja liskot. Kaupunkialueilla haukat syövät puluja ja kottaraisia. Saalistarjonta vaihtelee alueiden ja vuodenajan mukaan, mutta tärkeässä osassa ravintoa ovat jyrsijät, jotka muodostavat 85 prosenttia amerikanhiirihaukan ruokavaliosta.
Amerikanhiirihaukka (Buteo jamaicensis) on yleissävyltään ruosteenruskea petolintu, joka pesii miltei koko Pohjois-Amerikan alueella, länsi-Alaskasta ja pohjois-Kanadasta jopa Panamaan ja Karibian saarten alueelle asti. Se on yleisimpiä Pohjois-Amerikan hiirihaukkojen (buteo) sukuun kuuluvia haukkoja. Amerikanhiirihaukoista on tunnistettu 14 eri alalajia, joiden ulkonäkö ja levinneisyys vaihtelee. Se on myös kookkaimpia Pohjois-Amerikan Buteo-suvun haukkoja: amerikanhiirihaukka painaa noin 690–1 600 g, pituus on 45–65 cm ja siipien kärkiväli 110–145 cm.
Amerikanhiirihaukkoja kasvatetaan käytettäviksi haukkametsästyksessä. Koska laji on niin yleinen ja helposti koulutettavissa metsästystarkoituksiin, suurin osa haukkametsästykseen valituista linnuista Yhdysvalloissa on amerikanhiirihaukkoja. Haukkametsästyksen harrastajien on lupa ottaa käyttöön vain haukkoja, jotka ovat jättäneet pesänsä ja omillaan mutta ovat alle vuoden vanhoja, jotta pesimäpopulaatio ei vaarantuisi. Näitä haukkoja suositaan myös siksi, koska kyseisille nuoremmille linnuille ei ole kehittynyt täysikasvuisten käyttäytymistapoja, jotka tekisivät koulutuksesta huomattavasti haastavampaa. Pesiviä ja poikasia pitäviä täysikasvuisia amerikanhiirihaukkoja on laitonta ottaa metsästystarkoituksiin.
Buteo jamaicensis
La Buse à queue rousse (Buteo jamaicensis) est une espèce d'oiseaux de proie, ou rapaces d'Amérique du Nord.
La Buse à queue rousse adulte a la queue de couleur rousse (ce qui lui a donné son nom), terminée ou non par une barre noire. Elle a des ailes longues et larges. L'adulte a le dos et le haut des ailes brun foncé. Son plumage est variable, allant du brun roux clair au brun foncé. Les parties inférieures sont plus claires que les supérieures. Le bas de l'abdomen est plus pâle que le reste du corps, traversé par une bande foncée. La queue est uniformément rousse et large. Le bec est court et crochu, la cire est jaune, l'extrémité est noire. Les yeux sont brun foncé. Les pattes et les doigts sont jaunes. La femelle est 25 % plus grande que le mâle, mais leurs plumages sont identiques. L'immature ressemble aux adultes, mais il a les yeux plus clairs. Il est davantage strié, sa queue est brune, barrée de plusieurs bandes foncées. On trouve deux phases, la claire et la foncée, et au moins 14 sous-espèces, avec de grandes différences au niveau du plumage et de l'habitat.
La Buse à queue rousse piaule ; son cri est une sorte de hennissement râpeux « keeeear ». Ce cri varie avec l'âge et le lieu. Il est souvent entendu quand il plane. Ce cri féroce est souvent utilisé comme un cri de rapace générique à la télévision ou dans d'autres médias, même si l'oiseau en question n'est pas une buse à queue rousse. Les jeunes émettent un doux et bas pépiement, devenant plus profond avec l'âge. Quand les parents quittent le nid, les jeunes émettent un vagissement perçant « Klee-uk » répété, pour quémander de la nourriture.
La Buse à queue rousse chasse de plusieurs manières, et capture toute sorte de proies. Généralement, elle reste sur un pylône ou un perchoir haut, et fond sur sa proie dès qu'elle est repérée. Mais elle peut aussi chasser en volant, regardant au sol avec attention, grâce à sa vue perçante lui permettant de détecter le moindre mouvement à grande distance. Elle peut détecter une souris à 100 mètres de hauteur.
Elle utilise ses puissantes serres comme une arme. Elle peut aussi voltiger sur place contre les vents, cherchant une proie au sol. La Buse à queue rousse est active pendant le jour. Les petites proies sont portées sur le perchoir pour y être dévorées, tandis que les plus grosses sont consommées au sol. Pendant la parade nuptiale, le couple plane en larges cercles en lançant des cris aigus, à grande hauteur. Le mâle plonge en un à pic abrupt, puis remonte, répétant ces manœuvres plusieurs fois, et à la fin, il s'approche de la femelle par en haut, et étend ses pattes pour agripper brièvement les serres de la femelle. Ils descendent alors en spirale vers le sol, se lâchant au dernier moment. Le mâle peut aussi attraper une proie et la passer à la femelle pendant le vol. Les deux partenaires s'accouplent après cette parade, debout sur un perchoir, se toilettant réciproquement, et là, la femelle permet au mâle de s'accoupler. La Buse à queue rousse, comme la plupart des autres oiseaux, a des postures corporelles qui expriment un langage. Posture agressive, avec la tête et le corps dressés et les plumes hérissées; posture de soumission, avec la tête basse et les plumes lisses ; parades aériennes pendant la période nuptiale ; vol ondulant et piqués, utilisés aussi dans la défense du territoire. La Buse à queue rousse s'accouple pour la vie. Ce sont des oiseaux territoriaux, défendant agressivement leur zone, la femelle plutôt près du nid, et le mâle à travers tout le territoire.
La Buse à queue rousse vit dans les zones herbeuses, les marais buissonneux, mais aussi dans les déserts ou les forêts, depuis le niveau de la mer jusqu'à des altitudes variables, mais près d'un cours d'eau, d'un lac ou d'un champ.
Elle n'hésite pas à même s'installer en ville (On la trouve même dans Manhattan, et dans Central Park)
La Buse à queue rousse se reproduit depuis l'Alaska jusqu'au Labrador, et vers le sud, jusqu'au Mexique, Bahamas et Caraïbes, et Amérique centrale. Elle hiverne depuis le sud du Canada jusque vers le sud. Les oiseaux du nord migrent au sud en hiver, mais la plupart des autres oiseaux sont résidents à l'année.
La Buse à queue rousse a un vol agile et puissant, effectuant des vols acrobatiques pendant la parade nuptiale. C'est un rapace qui vole haut. Il plane sans effort avec les ailes tendues en un V peu profond. C'est un oiseau très actif en vol, battant beaucoup des ailes.
Le nid de la Buse à queue rousse est un grand bol volumineux. Il est fait de brindilles, écorces, et feuilles, haut dans un arbre ou sur le bord d'une falaise. Il peut être réutilisé année après année. Le nid est construit par les deux adultes. Des matériaux frais, aiguilles de conifères et matériaux végétaux verts, sont déposés dans le nid tout au long de la période de reproduction, afin de le garder propre. La femelle dépose 1 à 5 œufs blancs ou blanc bleuté, variablement tachetés de brun clair. L'incubation dure environ 28 à 35 jours, assurée par les deux parents, davantage par la femelle qui est nourrie au nid par le mâle. Les jeunes naissent nidicoles. Ils sont couverts de duvet blanc et grandissent lentement. Pendant cette période, la femelle les couve, et le mâle nourrit les poussins et la femelle en apportant de la nourriture au nid. La femelle nourrit les petits avec des petits morceaux prélevés sur les proies apportées. Les poussins peuvent abandonner le nid à environ 42 à 46 jours, mais cette période peut durer jusqu'à dix semaines, le temps d'apprendre à voler et à chasser. Les jeunes atteignent leur maturité sexuelle au bout de 3 ans, et cette espèce ne produit qu'une seule couvée par saison.
La Buse à queue rousse se nourrit principalement de petits mammifères (souris, rats, écureuils, rats musqués, belettes), d'oiseaux (canards, pigeons, râles, tourterelles, pics, faisans, corneilles et rarement de la volaille), des reptiles et des amphibiens, des poissons et des invertébrés. La Buse ne boit que très peu d'eau, sauf quand la température dépasse 33°.
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La Buse à queue rousse a peu de prédateurs, tels que le grand-duc d'Amérique et les corvidés, les renards roux et les ratons laveurs, qui dévorent poussins et œufs. Elle est menacée par les tirs, les collisions diverses, la perte de l'habitat et les dérangements humains sur les sites de reproduction. L'empoisonnement par le plomb tue aussi beaucoup d'oiseaux chaque année.
La Buse à queue rousse est un oiseau utilisé en fauconnerie en Amérique comme en Europe. Bien plus puissante que la Buse variable européenne, elle est utilisée pour la chasse au vol. Principalement utilisée pour capturer des proies comme des lapins ou des lièvres, elle est aussi capable de s'attaquer à des oiseaux.
D'après Alan P. Peterson, cette espèce est constituée des 15 sous-espèces suivantes :
Buse à queue rousse
Une buse à queue rousse à The Ramble et The Lake de Central Park à New York. Avril 2022.
Buteo jamaicensis
La Buse à queue rousse (Buteo jamaicensis) est une espèce d'oiseaux de proie, ou rapaces d'Amérique du Nord.
La poiana della Giamaica (Buteo jamaicensis J. F. Gmelin, 1788) o poiana codarossa è un uccello rapace della famiglia degli Accipitridi.[2] È il rapace americano più diffuso, e vive dal Canada meridionale al Centro America. Le due principali sottospecie sono quella scura e quella chiara riconoscibili dalla variazione del piumaggio che è rispettivamente: quasi completamente marrone scuro con qualche leggera stiratura bianca sul sottoala e leggermente rossiccia sulla coda; l'altra invece è molto più bianca con striature marrone scuro e marrone rossicce soprattutto sulla coda da dove prende il suo nome comune, assomiglia alla poiana comune( buteo buteo) soltanto che il marrone è più appunto rossiccio. Possiede un'incredibile capacità di adattamento, che le permette di sopravvivere negli habitat più disparati e di cacciare le prede più diverse: dalle praterie, dove caccia lepri, conigli e cani della prateria, alle giungle dove insegue grandi invertebrati e iguane, alle paludi dove mangia procioni, opossum e moffette, ai cigli delle strade, dove divora le carcasse degli animali investiti, fino alle grandi città, dove caccia gli uccelli. È a sua volta preda di linci rosse, coyote, gufi della Virginia, aquile reali, alligatori, puma e cani; sovente sono anche investite dalle automobili. Nonostante ciò, il loro altissimo numero fa in modo che esse non siano considerate a rischio di estinzione. Deve il suo nome scientifico al luogo dove è stata scoperta (la Giamaica) e il suo nome comune al colore della coda.
Il suo grido, lungo e acuto, viene spesso utilizzato come effetto sonoro di repertorio per gli uccelli rapaci nei media, anche quando il rapace in questione non è una poiana codarossa (ad esempio va spesso a sostituire il grido dell'aquila calva).[3][4]
Esemplare in ambiente urbano
In volo sul mare
La poiana della Giamaica (Buteo jamaicensis J. F. Gmelin, 1788) o poiana codarossa è un uccello rapace della famiglia degli Accipitridi. È il rapace americano più diffuso, e vive dal Canada meridionale al Centro America. Le due principali sottospecie sono quella scura e quella chiara riconoscibili dalla variazione del piumaggio che è rispettivamente: quasi completamente marrone scuro con qualche leggera stiratura bianca sul sottoala e leggermente rossiccia sulla coda; l'altra invece è molto più bianca con striature marrone scuro e marrone rossicce soprattutto sulla coda da dove prende il suo nome comune, assomiglia alla poiana comune( buteo buteo) soltanto che il marrone è più appunto rossiccio. Possiede un'incredibile capacità di adattamento, che le permette di sopravvivere negli habitat più disparati e di cacciare le prede più diverse: dalle praterie, dove caccia lepri, conigli e cani della prateria, alle giungle dove insegue grandi invertebrati e iguane, alle paludi dove mangia procioni, opossum e moffette, ai cigli delle strade, dove divora le carcasse degli animali investiti, fino alle grandi città, dove caccia gli uccelli. È a sua volta preda di linci rosse, coyote, gufi della Virginia, aquile reali, alligatori, puma e cani; sovente sono anche investite dalle automobili. Nonostante ciò, il loro altissimo numero fa in modo che esse non siano considerate a rischio di estinzione. Deve il suo nome scientifico al luogo dove è stata scoperta (la Giamaica) e il suo nome comune al colore della coda.
Il suo grido, lungo e acuto, viene spesso utilizzato come effetto sonoro di repertorio per gli uccelli rapaci nei media, anche quando il rapace in questione non è una poiana codarossa (ad esempio va spesso a sostituire il grido dell'aquila calva).
Buteo jamaicensis (nomen a Ioanne Gmelin anno 1788 factum) est species buteonum familiae Accipitridarum. Species primum Iamaicae reperta est, sed in paene tota America Septentrionali invenitur.[2]
Haec stipula ad avem spectat. Amplifica, si potes! Buteo jamaicensis (nomen a Ioanne Gmelin anno 1788 factum) est species buteonum familiae Accipitridarum. Species primum Iamaicae reperta est, sed in paene tota America Septentrionali invenitur.
De roodstaartbuizerd (Buteo jamaicensis) is een roofvogel behorend tot de familie Acciptridae.
Mannelijke roodstaartbuizerds zijn met een lengte van 45-56 cm en een gewicht van 700-1300 gram duidelijk kleiner dan de vrouwelijke vogels, die 50–65 cm lang zijn en 1100–1900 gram wegen.
Deze soort vindt zijn prooi door vliegend de grond af te zoeken of door de omgeving af te speuren vanuit een hoge boom of vanaf een telefoonpaal. Wanneer een prooi wordt gezien, vangt de roodstaartbuizerd het dier met een stootduik. Zoogdieren, vogels, reptielen en insecten vallen ten prooi aan deze roofvogel.
Deze soort leeft van West-Alaska en Noord-Canada tot Panama en de Antillen. Het leefgebied van de roodstaartbuizerd is zeer gevarieerd en bestaat onder andere uit bossen, savannes en bergweiden.
De soort telt 12 ondersoorten:
Roodstaartbuizerd eet prooi
Roodstaartbuizerd in de wind
Roep van de roodstaartbuizerd
De roodstaartbuizerd (Buteo jamaicensis) is een roofvogel behorend tot de familie Acciptridae.
Multimedia w Wikimedia Commons Myszołów rdzawosterny (Buteo jamaicensis) – gatunek ptaka z rodziny jastrzębiowatych (Accipitridae). Duży i krępy drapieżnik.
Wyróżniono kilkanaście podgatunków B. jamaicensis[4][2][5]:
Ameryka Północna i Środkowa, aż po Panamę i wyspy położone w basenie Morza Karaibskiego.
Myszołów rdzawosterny (Buteo jamaicensis) – gatunek ptaka z rodziny jastrzębiowatych (Accipitridae). Duży i krępy drapieżnik.
O búteo-de-cauda-vermelha (Buteo jamaicensis) ou mioto-da-Jamaica[2] é uma espécie de ave de rapina existente na América do Norte. Ambos os sexos têm plumagem e peso semelhante. Os adultos possuem caudas mais pequenas e uma envergadura de asas maiores que os juvenis.
O búteo-de-cauda-vermelha (Buteo jamaicensis) ou mioto-da-Jamaica é uma espécie de ave de rapina existente na América do Norte. Ambos os sexos têm plumagem e peso semelhante. Os adultos possuem caudas mais pequenas e uma envergadura de asas maiores que os juvenis.
Șorecar de coadă roșie (Buteo jamaicensis) este un membru din ordinul păsărilor Falconiformes care include toate răpitoarele diurne, acvile, Milvinae, și șoimi care au multe caracteristice fizice asemănătoare. Aparține grupului Buteos, care sunt răpitoare de o mărime mare dar mai mici decât acvilele și cu aripile în general late și lungi. Acest grup are 27 de specii distribuite pe tot globul, fiind mai cunoscut Șorecarul comun.
Originar din continentul american și necunoscut în mare parte în Europa, Șorecarul de coadă roșie (Buteo jamaicensis) a fost clasificat pentru prima dată de naturalistul german Gmelin în 1788 Jamaica, este una dintre răpitoarele cele mai folosite la vânătoare în America de Nord.
În actualitate s-au descris până la 15 posibile subspecii ale acestui frumos răpitor.
Această subspecie se găsește răspândită de-a lungul continentului american, din Alaska și Canada trecând prin Statele Unite până în Mexic, Caribe, Cuba și Panama. Nu s-au găsit indivizi în afara acestei zone, excepție exemplare care au fost importate și au scăpat din captivitate. Variațiile între subspecii de coadă roșie, plus diferiții hibrizi naturali produși între respectivele subspecii și alti Buteo, sunt considerabile, rezultând uneori dificil de recunoscut și clasificat datorita variației de mărime și plumaj. Plumajul de tânăr și adult este foarte asemănător pentru toate subspeciile, adulții au aripile mai late și coada mai scurtă; unica diferență importanta este coada care la tineri nu este roșie încă. Linea abdominală este mai marcată la tineri decât la adulți în cadrul aceeleași subspecii.
Masculii și femelele sunt similare la plumaj și în cazul Buteo jamaicensis nu putem să ne bazăm pe plumaj și mărime pentru a determina sexul.
Șorecarul de coadă roșie primește numele datorită culorii superficiale superioară a cozii, un ton care merge de la roșu portocaliu, roz palid până la roșu intens, și care apare în a doua toamnă după prima schimare a penajului. În majoritatea exemplarelor adulte la sfârșitul cozii apare o linie lată și închisă de culoare neagră. La suprafața inferioară a cozii este de un alb intens, în unii indivizi poate avea culoare argintată. Fiind una dintre răpitoarele cele mai numeroase, este foarte folosit în vânătoarea de răpitoare dresate, în special în America de nord și Marea Britanie, folosită de către principianți cât și de maeștrii, în multe demonstrații specifice.
Șorecar de coadă roșie (Buteo jamaicensis) este un membru din ordinul păsărilor Falconiformes care include toate răpitoarele diurne, acvile, Milvinae, și șoimi care au multe caracteristice fizice asemănătoare. Aparține grupului Buteos, care sunt răpitoare de o mărime mare dar mai mici decât acvilele și cu aripile în general late și lungi. Acest grup are 27 de specii distribuite pe tot globul, fiind mai cunoscut Șorecarul comun.
Originar din continentul american și necunoscut în mare parte în Europa, Șorecarul de coadă roșie (Buteo jamaicensis) a fost clasificat pentru prima dată de naturalistul german Gmelin în 1788 Jamaica, este una dintre răpitoarele cele mai folosite la vânătoare în America de Nord.
În actualitate s-au descris până la 15 posibile subspecii ale acestui frumos răpitor.
Această subspecie se găsește răspândită de-a lungul continentului american, din Alaska și Canada trecând prin Statele Unite până în Mexic, Caribe, Cuba și Panama. Nu s-au găsit indivizi în afara acestei zone, excepție exemplare care au fost importate și au scăpat din captivitate. Variațiile între subspecii de coadă roșie, plus diferiții hibrizi naturali produși între respectivele subspecii și alti Buteo, sunt considerabile, rezultând uneori dificil de recunoscut și clasificat datorita variației de mărime și plumaj. Plumajul de tânăr și adult este foarte asemănător pentru toate subspeciile, adulții au aripile mai late și coada mai scurtă; unica diferență importanta este coada care la tineri nu este roșie încă. Linea abdominală este mai marcată la tineri decât la adulți în cadrul aceeleași subspecii.
Masculii și femelele sunt similare la plumaj și în cazul Buteo jamaicensis nu putem să ne bazăm pe plumaj și mărime pentru a determina sexul.
Șorecarul de coadă roșie primește numele datorită culorii superficiale superioară a cozii, un ton care merge de la roșu portocaliu, roz palid până la roșu intens, și care apare în a doua toamnă după prima schimare a penajului. În majoritatea exemplarelor adulte la sfârșitul cozii apare o linie lată și închisă de culoare neagră. La suprafața inferioară a cozii este de un alb intens, în unii indivizi poate avea culoare argintată. Fiind una dintre răpitoarele cele mai numeroase, este foarte folosit în vânătoarea de răpitoare dresate, în special în America de nord și Marea Britanie, folosită de către principianți cât și de maeștrii, în multe demonstrații specifice.
Myšiak červenochvostý (Buteo jamaicensis) je stredne veľký dravý vták z čeľade jastrabovitých. Hniezdi takmer na celom území Severnej Ameriky, v rozmedzí od západnej Aljašky a severnej Kanady až po Panamu a Karibik. Patrí medzi najrozšírenejšie severoamerické myšiaky. Vyskytuje sa v 14 poddruhoch, ktoré sa medzi sebou líšia sfarbením a areálovým rozšírením.
Myšiak červenochvostý dorastá do výšky 45 – 65 cm a rozpätie krídel sa pohybuje od 110 cm do 145 cm, samice pritom bývajú o 25 % väčšie než samci. Hmotnosť u dospelých jedincov sa obvykle pohybuje medzi 690 – 1 600 g. Zvrchu je hnedý, spodok má svetlejší s výraznými hnedými fľakmi a chvost charakteristicky tehlovo sfarbený.
Obýva širokú paletu lokalít v rôznych nadmorských výškach, vrátane púští, pastvín, ihličnatých, listnatých i tropických dažďových pralesov, poľnohospodárske pôdy a mestské oblasti. V Kanade, Mexiku a Spojených štátoch je chránený.
Živí sa najmä malými cicavcami, ale tiež vtákmi, plazmi a vzácnejšie i netopiermi, hadmi, rybami, kôrovcami a hmyzom. Zloženie jeho potravy sa mení podľa oblasti a ročného obdobia, až 85 % z jeho potravy však zvyčajne zaberajú hlodavce. Je monogamný. Kladie 2 – 3 vajcia, na ktorých sedí po dobu 28 – 35 dní.
Vďaka jeho zatiaľ pomerne vysokej početnosti a ľahkému výcviku sa často využíva v sokoliarstve. Má tiež význam u niektorých pôvodných severoamerických kmeňov, ktorí jeho perá považovali za posvätné a využívali ich pri náboženských obradoch.
Commons ponúka multimediálne súbory na tému Myšiak červenochvostý
Tento článok je čiastočný alebo úplný preklad článku Káně rudoocasá na českej Wikipédii.
Myšiak červenochvostý (Buteo jamaicensis) je stredne veľký dravý vták z čeľade jastrabovitých. Hniezdi takmer na celom území Severnej Ameriky, v rozmedzí od západnej Aljašky a severnej Kanady až po Panamu a Karibik. Patrí medzi najrozšírenejšie severoamerické myšiaky. Vyskytuje sa v 14 poddruhoch, ktoré sa medzi sebou líšia sfarbením a areálovým rozšírením.
Rödstjärtad vråk[2] (Buteo jamaicensis) är en nordamerikansk fågel i familjen hökartade rovfåglar inom ordningen hökfåglar.[3]
Rödstjärtad vråk är en av de största Buteo-arterna i Nordamerika. Den mäter 45–65 centimeter, har ett vingspann på 110–145 centimeter och väger 700–1600 gram. Honorna väger i genomsnitt 25% mer än hanarna.[4]
Rödstjärtad vråk häckar i större delen av Nordamerika, från västra Alaska och norra Kanada och så långt söderut som Panama och Västindien. Den är den vanligaste och mest spridda arten i släktet Buteo i Nordamerika.
Här listas 14 underarter fördelade på tolv grupper efter Clements et al, med olika utseende och utbredning:[3]
Ibland urskiljs också underarten suttoni med utbredning i södra Baja California.[5]
I flykten
Subadult
Ljus morf
Den rödstjärtade vråken är anpassad till nästan alla naturtyper i utbredningsområdet och förekommer i exempelvis öken, grässlätt, barrskog, lövskog, tropisk regnskog, jordbruksområden och städer. De enda områdena där den saknas är mycket stora sammanhängande skogar och arktiska områden.
IUCN kategoriserar arten som livskraftig.[1] I Kanada, USA och Mexiko är den skyddad av "Migratory Bird Treaty Act" (Fördraget om flyttfåglar). På grund av att de är vanliga och lätta att träna utgör de majoriteten av de vråkar som fångas för att användas av falkenerare I USA. Falkenerare får endast fånga vråkarna under tiden från att de lämnat boet tills de fyllt ett år.[6] Fåglarna i denna ålder som är lättast att träna till falkenerarjakt.
Wikimedia Commons har media som rör rödstjärtad vråk.
Wikispecies har information om Buteo jamaicensis.
Rödstjärtad vråk (Buteo jamaicensis) är en nordamerikansk fågel i familjen hökartade rovfåglar inom ordningen hökfåglar.
Kızıl kuyruklu şahin[1] (Buteo jamaicensis), atmacagiller (Accipitridae) familyasından Kuzey Amerika'da yaygın yırtıcı kuş türü. Batı Alaska'dan kuzey Kanada'ya, güneyde Panama'ya ve Karayipler'e kadar Kuzey Amerika'nın büyük bölümünde ürer ve bu bölgede en yaygın Buteo türlerinden biridir. Kızıl kuyruklu şahin yaşadığı bölgede tüm biyomlara uyum sağlayabilir. Görünüşleri ve yaşadıkları yerler ile birbirlerinden ayrılan on dört alt türü kabul edilmiştir. Boyları 45–65 cm, kanat açıklıkları 110–145 cm ve ağırlıkları 690-1600 g arasında değişir. Bu boyutlarıyla, Kuzey Amerika'da yaşayan Buteo cinsi kuşların en büyük üyelerinden biridir. Eşeysel dimorfizm gösteren kızıl kuyruklu şahinin dişileri erkeklerinden daha büyüktür.
Bazen ayrı bir tür olarak değerlendirilen Harlan şahini (B.j. harlani) aşağıda taksonomi bölümünde anlatılmaktadır.
Kızıl kuyruklu şahin çöller, otlaklar, ormanlar, tropikal yağmur ormanları, tarım alanları ve kentsel bölgeler de dahil olmak üzere birçok biyomda ve yükseklikte yaşayabilir. Arktika'nın üst enlemleri ve yoğun ormanlar dışında Kuzey Amerika'nın her yerinde bulunur. Kanada, Meksika ve ABD'de yasa ile koruma altına alınmıştır.
Çok yaygın oldukları ve yetenekli bir avcı olarak yetiştirilebildikleri için, ABD'de atmacacılık için yakalanan şahinlerin büyük bölümü kızıl kuyruklu şahinlerdir. Üreyen popülasyonu etkilememek için, atmacacıların yalnızca yuvadan ayrılmış, bir yaşından küçük ve göç eden kuşları yakalama izinleri bulunur. Üreyen ve yavru besleyen erişkinlerin atmacacılık için yakalanması yasadışıdır. Bir yaşını doldurmamış şahinler aynı zamanda kolay eğitilebildikleri için de tercih edilmektedir.
Kızıl kuyruklu şahin Amerika Yerlileri kültüründe önemli bir yere sahiptir. Tüyleri bazı kabileler tarafından kutsal sayılır ve dini törenlerde kullanılır.
Erkek kuşlar 45–65 cm boyunda ve 690-1300 gram ağırlığında olabilirken, dişiler 48–65 cm. boyunda ve 900-2000 gram ağırlığında olabilmektedirler. Kanat açıklıkları 114–133 cm. arasındadır. Birçok yırtıcı kuş türünde olduğu gibi eşeysel dimorfizm gösterirler ve dişiler erkeklerden %25 daha büyüktür.[2]
Kızıl kuyruklu şahinin tüyleri alt türlere ve bulundukları bölgelere göre farklılık gösterir. Bu renk varyasyonları tüy dökme ile ilgili değildir ve polimorfizme bağlıdır. Kuzey Amerika'nın batısında bulunan B.J. calurus en çok değişkenlik gösteren alt türdür ve üç farklı renk tipi içerir: açık, koyu ve orta ya da pas rengi. Koyu ve pas rengi tipler popülasyonun %10-20'sini oluşturur.[3]
Renk tonları ve izler farklılık gösterse de kızıl kuyruklu şahinin temel görünüşü tür içinde tutarlıdır. Karınaltı tüyler sırttan daha açık renklidir ve karın boyunca koyu kahverengi bir bant hemen hemen tüm renk tiplerinde bulunur. Bu türe adını veren kızıl kuyruk üstte tuğla kırmızısı, altta da pembe renklidir.[4] Gaga, yırtıcı kuşlara özgü biçimde çengel şeklindedir ve koyu renklidir. Kısa, geniş kuyrukları ve kalın kanatları bulunur.[4] Gaganın dibi, ayaklar ve bacaklar sarı renklidir.[2]
Erişkin olmayan kuşlar, yakın mesafeden sarı renkli irisleriyle ayırdedilir. Kuşlar 3-4 yılda erginliğe erişirken iris de yavaşça koyulaşır ve kızılımsı kahverengi bir tona kavuşur. Açık ve koyu renk tonlu tiplerin hepsinde yetişkin olmayan kızıl kuyruklu şahinin kuyruğunda bant şeklinde birçok koyu bölge bulunur.[4]
Kızıl kuyruklu şahin sağlam yapılı, geniş kanatlı ve orta boyutlu gündüz yırtıcı kuşlarından oluşan Buteo cinsinin bir üyesidir. Bu cinse üye olan kuşlar şahin olarak bilinir.[5] Görünüşleri ve yaşadıkları yerler ile birbirlerinden ayrılan on dört alt türü kabul edilmiştir:
Adalarda yaşayan dört alt türün (jamaicensis, solitidinus, socorroensis ve fumosus) yaşam alanları diğer alt türler ile kesişmemektedir.
Kızıl kuyruklu şahin Amerika kıtasında en yaygın bulunan şahin türlerinden biridir. Kuzeyde Alaska'nın ortası, Yukon, Kuzeybatı Toprakları, Quebec'in doğusu ve güneyi, New Brunswick, Nova Scotia Prens Edward Adası'nda, güneyde Florida, Karayipler ve Orta Amerika'da ürerler. Kışlama alanları Kanada'nın güneyinden güneyde üreme alanlarının bulunduğu yerlere kadar uzanır.[7]
Tercih ettiği yaşama alanları tünek olarak kullanılabilecek yüksek kayalıklar ya da ağaçlar bulunan ormanlar ve tarlalardır. Kızıl kuyruklu şahin çöller, otlaklar, ormanlar, tropikal yağmur ormanları, tarım alanları ve kentsel bölgeler de dahil olmak üzere birçok biyomda ve yükseklikte yaşayabilir.[9] Arktika'nın üst enlemleri ve yoğun ormanlar dışında Kuzey Amerika'nın her yerinde bulunur.[3] Kuzey Amerika'nın biyomlarını kullanma konusunda gökdoğanın hemen ardından gelir.[10]
Kızıl kuyruklu şahin Kuzey Amerika'da çok yaygın olarak bulunur.[10] Kuzeydoğu'da ormanlık alanların açılması av alanları yaratmış, ağaçlıklı bölgelerin korunmasıyla da yuvaların olduğu bölgeler yerinde kalmıştır. Batı'da ağaç dikimiyle daha önce buralarda bulunmayan kızıl kuyruklu şahin yeni ağaçlıklı bölgelere de yuva yaparak bulunduğu bölgeleri genişletmiştir. Ağaç bulunmayan ara bölgelerde de uzun telefon, elektrik direkleri bulunan otoyolların yapılması avlanmak için gerekli yüksek tünekleri oluşturmuştur. Kızıl kuyruklu şahin şehirlerde de yaşamaktadır.[11]
Kızıl kuyruklu şahin, mümkün olduğunca çok enerji korumak için belli belirsiz bir V şeklinde açtığı kanatlarıyla havada süzülür. Etkin uçuşu yavaş ve derin kanat darbeleriyle belirgindir. Rüzgara karşı, kanat çırparak havada belirli bir noktada durabilir.[3] Süzülürken veya kanat çırparken genelde 32–64 km/s hızla uçar, ancak dalış yaptığında 190 km/s hıza ulaşabilir.[12]
Kızıl kuyruklu şahinin çağrısı iki-üç saniyelik kısık, kulak tırmalayıcı bir çığlıktır ve krii-iii-er[11] olarak tanımlanır; yüksek tiz perdeden başlar ve pese doğru iner.[12] Bu çığlık çoğu zaman istim düdüğü ile benzer ses olarak tanımlanmıştır.[2] Avlanırken ve süzülürken çığlık atan kızıl kuyruklu şahinin çağrıları bölgesine rakip bir şahin girdiğinde ya da başak bir avcı ile karşılaştığında sinirlendiğinde ve rahatsız olduğunda daha da yüksek seslidir.[11] Yakın mesafeden boğuk "gaa-rank" sesi çıkarır.[13] Genç şahinler, ebeveynler yuvadan ayrılınca, yemek için klii-ak diye inlerler.[14]
Kızıl kuyruklu şahin etobur ve fırsatçıdır. Ana besini küçük memelilerdir ama aynı zamanda kuşları ve sürüngenleri de yerler. Avları bölgeye ve mevsime göre değişir ama genelde diyetlerinin %85'ini oluşturan kemirgenlerden oluşur.[2] En yaygın avlandıkları hayvanlar arasında fare, tarla faresi, sincap, çayır köpeği ve marmotlar yer alır.[15][16] Bunların dışında azalan olasılıkla tavşanımsılar, sivri faregiller, yarasalar, yılanlar, sukuşları, balık, kabuklular ve böcekler de avladıkları hayvanlar arasındadır. Av büyüklüğü böceklerden, kendi ağırlığının iki katı olan tavşanlara kadar farklılık gösterir. Esâret altında, kışın kızıl kuyruklu şahin günde 135 gr besin alır.[14]
Kızıl kuyruklu şahin tünediği yüksek yerden avının üstüne çullanarak avlanır. Kuşları havada yakalar, alçaktan uçarak kara hayvanlarını takip ederek avlar.
Amerika puhusu benzer bir ekolojik nişi geceleri avlayarak doldurur. Alacakaranlıkta her iki kuş arasında bir av rekabeti ortaya çıkabilir ancak farklı kuluçka mevsimi ve etkin oldukları zamanlar nedeniyle doğrudan rekabet ile karşılaşılmaz. Her ne kadar kızıl kuyruklu şahinler, Amerika puhularının normal avlarından daha büyük olsa da[16] Amerika puhusu zaman zaman şahinleri de avlar.[15] Diğer rakipler arasında kır şahini, paçalı şahin ve bayağı çakır kuşu avları ve avlanma yöntemleri benzeşen diğer kuşlar da bulunur.[17][18] Boz porsukları takip eden ve avlarını kaçıran şahinler görülmüştür ve bu iki tür birbirlerine av açısından rakip sayılırlar.[19] Leşler üzerine rekâbet Amerika kargası ile ortaya çıkar ve bir arada çalışan birkaç karga bir şahini uzaklaştırabilir.[20] Kartallar ve paslı şahinler gibi daha büyük yırtıcı kuşlar ise kızıl kuyruklu şahinin avlarını çalabilirler.[2]
Kızıl kuyruklu şahin cinsel olgunluğa iki yaşında ulaşır. Eşlerden biri ölene kadar tek eşle çiftleşir. Ancak eşi öldüğünde yeni bir eş bulur.[21] Aynı yuva çift tarafından yıllarca savunulabilir. Kur sırasında erkek ve dişi kuş tiz çığlıklar atarak birbirleri etrafında geniş daireler çizerek uçarlar. Erkek havada akrobatik hareketler sergiler, birden dalıp tekrar yükselir. Bu hareketleri birkaç kere sergiledikten sonra bazen kısa bir süre için erkek dişinin pençelerini kendi pençeleriyle tutar. Kur uçuşları 10 dakika veya daha uzun sürebilir. Kur uçuşunun ardından çiftleşirler. Aslında kur uçuşu olmadan da sıklıkla çiftleşirler.
Çiftleşirken tünemiş olan dişi öne doğru eğilir ve erkeğin ayakları sırtına gelecek şekilde üzerine konmasına izin verir. Dişi kıvrılarak kuyruk tüyleri bir yana doğru çeker ve üste konan erkek kıvrılarak dışkılığını dişinin dışkılığı ile aynı hizaya getirir. Çiftleşme 5-10 saniye sürer. Kışın sonlarına doğru ve baharın başında, yumurtlama öncesi günde birkaç kere çiftleşilir.[22]
Aynı dönemde, yerden 4–21 m yüksek büyük ağaç tepelerinde ya da yerden 35 m.den yüksek kayalıklara ya da insan yapısı yüksek direklere çift çalı-çırpı toplayarak yuva yapar. Yuvanın çapı genellikle 71–97 cm arasındadır ve 90 cm. yüksekliğinde olabilir. Yuva yapılırken, çalı çırpı kullanılır ve çevresine ağaç kabuğu, çam kozalakları, mısır koçanları gibi materyeller sıralanır.
Amerika puhusu yuva yerleri için kızıl kuyruklu şahinlerle rekâbet hâlindedir. Her iki türün de birbirlerinin yumurtalarını yokettikleri ve yavrularını öldürdükleri bilinmektedir ama genel olarak birbirlerine yakın bölgelerde yuva yaparlar. Amerika puhusu yuva yapamadığı için varolan kızıl kuyruklu şahin yuvalarına el koyar. Amerika puhusu, kuluçkaya kızıl kuyruklu şahinlerden daha önce, aralık civarlarında yatmaya başlar. Dolayısıyla, eğer yuvaları kapıldıysa kızıl kuyruklu şahinler yeni yuva yapmak zorunda kalırlar. Yeni yuvalar eskisinin bir kilometreden daha yakınına kurulur. Genelde yeni yuvalar eski yuvanın birkaç yüz metre yakınında olur. Büyük bir kuş olması sebebiyle, baykuşlar, kargagiller ve rakunlar şahinlerin ancak yumurtalarını ve yavrularını avlayabilirler.[23]
Bulunulan enleme göre mart ile nisan aylarında 1 ila 3 yumurta yumurtlanır. Yumurta sayısı, erişkinlerin av bulabilmesine çok yakından bağlıdır. Yumurtlama iki günde bir yumurta şeklinde olur. Yumurtalar genelde 60x47 mm boyutlarındadır. Kuluçkaya daha çok dişi yatar; dişinin avlanmaya gittiği ya da kanatlarını açmak için ayrıldığı zamanlarda erkek kuluçkaya devam eder. Kuluçka sırasında daha çok erkek dişiyi besler. 28 ila 35 gün sonra 2-4 günlük süre içinde yumurtalar çatlar ve yavrular yumurtadan çıkar çıkmaz beslenmek zorundadır. Dişi yavrulara gözkulak olurken hem dişiye hem de yavrulara besini erkek getirir. Dişi gelen besini küçük parçalara ayırarak yavruları besler. 42 ila 46 gün sonra yavrular küçük uçuşlar için yuvadan ayrılırlar. Palazlanma süresi 10 hafta civarındadır ve bu sürede genç kuşlar uçmayı ve avlanmayı öğrenir.[2]
Kızıl kuyruklu şahin, özellikle eyalet ve federal yasalarla düzenlenen atmacacılıkta ABD'de çok yaygın olarak kullanılır. ABD'de nüfusu bir milyonu aşkın olduğu sanılan kızıl kuyruklu şahin popülasyonu üzerinde sayıları 5.000'den az olan atmacacıların önemli bir etkisi olmamaktadır.[24]
Av esnasında atmacacı şahini salarak yüksek bir yere tünemesine izin verir. Sonra köpeklerin yardımıyla yerden av kaldırılır. İyi eğitilmiş bir şahin, atmacacıyı ve köpeği takip eder çünkü onların eylemlerinin sonucunda av yakalayacağını bilir. Kuş avını yakaladığında atmacacıya avı doğrudan getirmez. Atmacacı kuşu ve avını bulup, dikkatlice yaklaşmalı ve avı kendi verdiği et ile takas etmelidir. Bu şahinler yakalandıktan sonra klasik çağrı çığlıklarını pek çıkarmazlar.[25]
Kızıl kuyruklu şahinlerin tüyleri ve diğer parçaları birçok Amerika yerli kabilesi için kutsaldır ve kel kartal ile kaya kartalı gibi tüyleri dini törenlerde ve kabile ilerigelenlerinin giysilerinde kullanılır. Özellikle belirgin kızıl kuyruk tüyleri kabileler arasında çok popülerdir.[26] Bu üç tür kuşun tüylerine ve vücut parçalarına sahip olmak ile ilgili kanun "kartal tüyü kanunu" düzenlenmiştir.[27][28]
Kızıl kuyruklu şahin (Buteo jamaicensis), atmacagiller (Accipitridae) familyasından Kuzey Amerika'da yaygın yırtıcı kuş türü. Batı Alaska'dan kuzey Kanada'ya, güneyde Panama'ya ve Karayipler'e kadar Kuzey Amerika'nın büyük bölümünde ürer ve bu bölgede en yaygın Buteo türlerinden biridir. Kızıl kuyruklu şahin yaşadığı bölgede tüm biyomlara uyum sağlayabilir. Görünüşleri ve yaşadıkları yerler ile birbirlerinden ayrılan on dört alt türü kabul edilmiştir. Boyları 45–65 cm, kanat açıklıkları 110–145 cm ve ağırlıkları 690-1600 g arasında değişir. Bu boyutlarıyla, Kuzey Amerika'da yaşayan Buteo cinsi kuşların en büyük üyelerinden biridir. Eşeysel dimorfizm gösteren kızıl kuyruklu şahinin dişileri erkeklerinden daha büyüktür.
Bazen ayrı bir tür olarak değerlendirilen Harlan şahini (B.j. harlani) aşağıda taksonomi bölümünde anlatılmaktadır.
Kızıl kuyruklu şahin çöller, otlaklar, ormanlar, tropikal yağmur ormanları, tarım alanları ve kentsel bölgeler de dahil olmak üzere birçok biyomda ve yükseklikte yaşayabilir. Arktika'nın üst enlemleri ve yoğun ormanlar dışında Kuzey Amerika'nın her yerinde bulunur. Kanada, Meksika ve ABD'de yasa ile koruma altına alınmıştır.
Çok yaygın oldukları ve yetenekli bir avcı olarak yetiştirilebildikleri için, ABD'de atmacacılık için yakalanan şahinlerin büyük bölümü kızıl kuyruklu şahinlerdir. Üreyen popülasyonu etkilememek için, atmacacıların yalnızca yuvadan ayrılmış, bir yaşından küçük ve göç eden kuşları yakalama izinleri bulunur. Üreyen ve yavru besleyen erişkinlerin atmacacılık için yakalanması yasadışıdır. Bir yaşını doldurmamış şahinler aynı zamanda kolay eğitilebildikleri için de tercih edilmektedir.
Kızıl kuyruklu şahin Amerika Yerlileri kültüründe önemli bir yere sahiptir. Tüyleri bazı kabileler tarafından kutsal sayılır ve dini törenlerde kullanılır.
Неоарктичний канюк за розміром близький до канюка прерієвого, але дещо довший і з трохи меншим розмахом крил. Вага в середньому від 700 г до 1,6 кг, самки на чверть важчі від самців. Довжина тіла становить близько 45-65 см, розмах крил 110—145 см[3]. Дорослі особини переважно темно-буро-рябі зверху і з охристо-рудим хвостом. Забарвлення нижньої частини світло-рябе, часом майже біле, бурі плямки більше сконцентровані на животі, хвіст візуально дещо темніший. Забарвлення молодих особини більш мінливе, хвіст зверху не такий рудий, в тон загального забарвлення, часто темніший, ніж у дорослих особин. В польоті кінці пер крил та плечі темніші, хвіст віялом. Статевого диморфізму за забарвленням немає, самці і самиці забарвлені подібно[4]. У цього хижака потужний загнутий донизу дзьоб та міцні кігті.
Неоарктичний канюк зареєстрований у всіх 50 штатах США та 12 провінціях/територіях Канади, а також у Мексиці, на Багамах та на Кубі. Птахи з північніших районів зазвичай мігрують на південь, рятуючись від сильних морозів[5].
Антропогенний фактор справив вирішальний вплив на розселення неоарктичного канюка. Вирубування лісів створило відкриті місця, необхідні для полювання, а насадження дерев у степових районах дало можливості для гніздування, подібно як і стовпи електропередач та інші високі палі, які ідеально допомагають канюку в його тактиці полювання з високих присад.
Ворона американська атакує канюка, який схопив пташеня
Птахи більше полюбляють відкриті місцевості на межею з лісом чи окремими деревами, на яких вони гніздяться. У гніздо на висоті до 25 м самиця відкладає 1-4 білуватих яєць, які висиджує 27-33 дні. Молодь вилітає з гнізда після 5 тижнів[6].
Загалом виділяють 14 підвидів Buteo jamaicensis, які різняться за розмірами і забарвленням:
Це незавершена стаття з орнітології.Buteo jamaicensis (tên tiếng Anh: Ưng đuôi lửa) là một loài chim săn mồi trong họ Ưng. Đây là một trong ba loài được biết đến với tên ở Mỹ là "chickenhawk" mặc dù nó hiếm khi săn bắt gà.[2] Nó sống ở suốt các khu vực của Bắc Mỹ, từ phía tây Alaska và miền bắc Canada tới phía nam Panama và Tây Ấn. Đây là một trong những loài Ưng phổ biến nhất ở Bắc Mỹ. Ưng đuôi lửa có thể thích nghi với tất cả các quần xã sinh vật trong phạm vi của nó. Có tất cả mười bốn phân loài được công nhận, tùy theo thay đổi về ngoại hình và phạm vi phân bố. Nó là một trong những thành viên lớn nhất của chi Buteo ở Bắc Mỹ. Chúng thường có trọng lượng từ 690-1600 gram (1,5-3,5 kg) và cao 45–65 cm (18–26 in), với sải cánh dài 110–145 cm (43–57 in). Ưng đuôi lửa hiển thị tính dị hình lưỡng tính trong kích thước khi con cái trung bình nặng hơn so với con đực khoảng 25%.[3]
Buteo jamaicensis (tên tiếng Anh: Ưng đuôi lửa) là một loài chim săn mồi trong họ Ưng. Đây là một trong ba loài được biết đến với tên ở Mỹ là "chickenhawk" mặc dù nó hiếm khi săn bắt gà. Nó sống ở suốt các khu vực của Bắc Mỹ, từ phía tây Alaska và miền bắc Canada tới phía nam Panama và Tây Ấn. Đây là một trong những loài Ưng phổ biến nhất ở Bắc Mỹ. Ưng đuôi lửa có thể thích nghi với tất cả các quần xã sinh vật trong phạm vi của nó. Có tất cả mười bốn phân loài được công nhận, tùy theo thay đổi về ngoại hình và phạm vi phân bố. Nó là một trong những thành viên lớn nhất của chi Buteo ở Bắc Mỹ. Chúng thường có trọng lượng từ 690-1600 gram (1,5-3,5 kg) và cao 45–65 cm (18–26 in), với sải cánh dài 110–145 cm (43–57 in). Ưng đuôi lửa hiển thị tính dị hình lưỡng tính trong kích thước khi con cái trung bình nặng hơn so với con đực khoảng 25%.
Buteo jamaicensis Hartlaub, 1860
Охранный статус
Краснохво́стый сары́ч[1] (лат. Buteo jamaicensis) — хищная птица из семейства ястребиных.
Краснохвостый сарыч длиной от 45 до 58 см, размах крыльев составляет от 107 до 141 см. Самцы меньше чем самки. Крылья широкие, закруглённые, клюв значительно сильнее чем у мохноногого канюка. Окраска оперения очень изменчива. В ареале различают 14 подвидов, которые частично имеют различные цветовые морфы.
Краснохвостый сарыч широко распространён в Северной и Центральной Америке. Предпочитает леса, граничащие с открытыми ландшафтами, прерии с древесными растениями, а также пустыни.
Питается мелкими грызунами, а также мелкими птицами, рептилиями и амфибиями.
Краснохво́стый сары́ч (лат. Buteo jamaicensis) — хищная птица из семейства ястребиных.
红尾鵟（學名：Buteo jamaicensis）是一種中等體型的猛禽，在美國也被稱爲雞鷹。繁殖於北美廣大地區，從阿拉斯加西部到加拿大北部，最南則可抵達巴拿馬和西印度群島，是北美大陸最爲常見的一種鵟屬鳥，根據外表和分佈地區，可分爲14個亞種。
分佈在北美的鵟屬各種鳥中最大的成員之一，體重為690-2000克，體長45-65釐米，翼寬110-145釐米。红尾鵟在體型上有比較明顯的雌雄二相性，雌鳥比雄鳥要大25%。红尾鵟的羽毛顔色比較多樣。
红尾鵟是對環境適應比較成功的物種，分佈在各種地形各種海拔的地區，包括沙漠、草原、針葉林、落葉林、熱帶雨林、農田和城區。除了北極地區外，它們在北美的大部分地區都可以看到。在加拿大、墨西哥和美國，红尾鵟還受到《1918年候鳥保護條例》的保護。
红尾鵟在北美的印第安土著文化中被用作標誌和象徵，其羽毛常被用作各種宗教儀式。
雄性红尾鵟的體重為690-1300克，體長為45-56釐米，雌性體重則達到900-2000克，體長50-65釐米。因此雌鳥通常都要比雄鳥大一些。
红尾鵟各亞種的羽毛差異較大，例如北美西部亞種B. j. calurus可以有淺紅褐色、深紅褐色和中紅褐色三個品種。其中淺紅褐色數量最多，佔一半以上，其他兩種顔色約為10-20%。
儘管顔色不同，红尾鵟的外表大致一樣。下腹部顔色較淺，背部則較深。腹部有一道深褐色的條紋，尾部上側為磚紅色，下側為粉紅色。喙部較短，色深，帶彎鈎。[2] 喙部、腿和腳都為黃色。[3]
幼鳥的虹膜為淺黃色，成年后顔色逐漸轉深，成鳥為紅褐色。
红尾鵟的名稱在歐洲被叫做buzzards，而在北美則被通稱為hawks。[4]
至少有14個已知亞種，包括：
其中的四個島嶼亞種jamaicensis、solitudinus、socorroensis和fumosus與其他亞種在分佈上不重合。
红尾鵟繁殖地區分佈於北美洲的阿拉斯加、加拿大的育空地區、西北地區，東到魁北克南部和大西洋諸省，向南抵達佛羅里達、西印度群島和中美洲。冬季則南移到加拿大南部以南的地區。[5]
棲息地包括森林和原野，分佈多樣性很大，[1]在北美洲僅次於游隼。[6]
飛行中的红尾鵟翅膀略微分佈在兩個平面上，拍打頻率較低，以保存體力。在高飛和拍打翅膀的狀態下，它們的飛行速度在20-40mph之間，但俯衝時的速度可以達到120mph。[7]红尾鵟在地面上行走時，腳步笨拙而緩慢。在追逐地面上的昆蟲和蛇類時，它們主要以跳躍爲主。
红尾鵟通常不攻擊人類和其他鳥類，但它們經常受到烏鴉、喜鵲、貓頭鷹和其他鷹類的襲擊。在受到威脅時，红尾鵟通常的策略是逃跑而不是保護巢穴。
叫聲為2-3秒刺耳的嘶叫，類似“kree-eee-ar”，開始音調較高，然後逐漸下降，類似水沸騰時的聲音。父母離開巢穴時，幼鳥則會發出類似“klee-uk”的聲音。[8]
播放媒体
红尾鵟在捕食上奉行機會主義。它們的食物主要包括各種小型哺乳動物、鳥和爬行類，例如嚙齒類、松雞、鵪鶉、水鳥、蝙蝠、鼩鼱、蛇、蜥蜴、甲殼類、昆蟲等等。
红尾鵟的食譜與大角鸮相似，因此在夜晚它們之間會爲了捕食展開競爭。
红尾鵟在三嵗左右達到性成熟期，為一夫一妻制，通常只有當原配死亡后，才會尋找新的配偶。雄鳥和雌鳥共同防禦巢穴。巢穴的建造一般發生在交配之後，建在4-21米以上的大樹上或35米以上的岩石上，有時它們也會選擇人類的建築作爲巢穴的所在地。巢穴一般直徑為71-97釐米，可達90釐米高，由樹枝、樹皮、針葉、根莖等組成。
四月產卵，每次產1-5卵，卵殼為藍白色，偶爾帶有褐色斑點。大小為60 x 47 毫米。雄鳥和雌鳥都參與孵卵，雄鳥孵卵時間較短，但負責給雌鳥覓食，孵化時間為28-35天。剛孵化的小鳥沒有毛，需要由雌鳥在巢穴中撫養。大約42-46天后，小鳥開始離開巢穴學習飛行。長羽的時間可達10周。
红尾鵟與人類的關係比較複雜。它們一方面可以控制嚙齒類和其他害獸的數量，另一方面也捕殺雞和其他家禽。由於一些誤會，有時會有農民射殺红尾鵟的事情發生。[9]不過红尾鵟目前受到條例保護。[10]
红尾鵟（學名：Buteo jamaicensis）是一種中等體型的猛禽，在美國也被稱爲雞鷹。繁殖於北美廣大地區，從阿拉斯加西部到加拿大北部，最南則可抵達巴拿馬和西印度群島，是北美大陸最爲常見的一種鵟屬鳥，根據外表和分佈地區，可分爲14個亞種。
分佈在北美的鵟屬各種鳥中最大的成員之一，體重為690-2000克，體長45-65釐米，翼寬110-145釐米。红尾鵟在體型上有比較明顯的雌雄二相性，雌鳥比雄鳥要大25%。红尾鵟的羽毛顔色比較多樣。
红尾鵟是對環境適應比較成功的物種，分佈在各種地形各種海拔的地區，包括沙漠、草原、針葉林、落葉林、熱帶雨林、農田和城區。除了北極地區外，它們在北美的大部分地區都可以看到。在加拿大、墨西哥和美國，红尾鵟還受到《1918年候鳥保護條例》的保護。
红尾鵟在北美的印第安土著文化中被用作標誌和象徵，其羽毛常被用作各種宗教儀式。
分類 界 : 動物界 Animalia 門 : 脊索動物門 Chordata 亜門 : 脊椎動物亜門 Vertebrata 綱 : 鳥綱 Aves 目 : タカ目 Accipitriformes 科 : タカ科 Accipitridae 属 : ノスリ属 Buteo 種 : アカオノスリ B. jamaicensis 学名 Buteo jamaicensis (Gmelin, 1788) 和名 アカオノスリ 英名 Red-tailed Hawk アカオノスリ（赤尾鵟、学名：Buteo jamaicensis）は、タカ目タカ科ノスリ属に分類される鳥類。
全長50-55cm。オスよりメスの方が大型になる。
食性は肉食性で、鳥類、小型哺乳類、爬虫類、両生類等を捕食する。上空を旋回したり、見通しのいい高所に止まりながら獲物を探す。
繁殖形態は卵生で、繁殖期は夏。岩棚や樹上、サボテン、送電塔などに営巣する。
LEAST CONCERN (IUCN Red List Ver. 3.1 (2001))
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