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Blue jays have been chosen as the mascot for many sports teams, including the Toronto Blue Jays, a professional baseball team.
(Reilly 1968)
Blue jays use bobbing motions when courting and when fighting. A signal of submission may be the "body-fluff" when the bird crouches down and fluffs up its feathers, holding the crest erect.
Blue jays have many calls. The one that is probably most familiar is the "jay" call for which it is named. This probably attracts other jays to join a flock or serves as an alarm call. Another call sounds like a rusty pump handle, and another sounds like a bell. Blue jays also make rattling sounds. In the spring you can hear very soft singing.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Blue jay populations are on the rise, and they are often very common where they occur. The range is expanding westward. Populations may have suffered somewhat in previous centuries as their wooded habitats were cleared and may suffer where epidemics of West Nile virus affect bird populations. Blue jays are corvids, which seem particularly susceptible to this virus. (Reilly 1968)
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no direct negative effects of blue jays on humans, although they may act as a reservoir for West Nile virus.
Blue jays are active and bold birds, making it easy to observe their fascinating behaviors.
Because they hide seeds and nuts and sometimes forget to find and eat them, these birds probably help plants disperse their seeds.
Ecosystem Impact: disperses seeds
Blue jays are omnivorous. They feed on fruits, nuts, seeds, insects, mice, frogs, and will rob other nests for small songbirds and bird eggs. To eat nuts, blue jays hold them with their feet and then crack the shell with their bill. Blue jays in captivity have been known to fashion tools in order to get at foods. Blue jays will also steal foods from other birds by frightening them into dropping what they have. They cache foods, such as seeds, for later use. (Reilly 1968)
Animal Foods: birds; mammals; amphibians; reptiles; eggs; insects; terrestrial non-insect arthropods
Plant Foods: seeds, grains, and nuts; fruit
Foraging Behavior: stores or caches food
Primary Diet: omnivore
Blue jays are native to the Nearctic region. They are common in southern Canada and in the United States, east of the Rocky Mountains. (Sanford 1984)
Biogeographic Regions: nearctic (Native )
Blue jays prefer mixed woodlands, particularly those with clearings. They are also common in suburban areas and city parks. (Reilly 1968)
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest
The oldest blue jay studied by researchers in the wild lived to be 17 years and 6 months old, most blue jays live to about 7 years old. One captive female lived for 26 years and 3 months.
Range lifespan
Status: wild: 17.5 (high) years.
Range lifespan
Status: captivity: 26.25 (high) years.
Average lifespan
Status: wild: 7 years.
Average lifespan
Status: wild: 210 months.
Blue jays are bright blue on top and whitish gray on the belly and chin. They have a gray-blue, feather crested head, which they can raise and lower. The feathers on their wings and tails are bright blue with white and black bands. Blue jays also have a collar of black feathers across the throat and continuing around the head. Their bills, legs, feet, and eyes are black. Males are just a little larger, on average, than females. Total body length ranges from 22 to 30 cm. (Reilly 1968)
Range mass: 65 to 109 g.
Range length: 22 to 30 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Blue jays will actively defend their nests against predators. Both parents will attack and chase hawks, falcons, raccoons, cats, snakes, squirrels, and even humans away from their nests. Adult blue jays are often preyed on by various species of hawks, owls, and falcons. Nestlings are preyed upon by squirrels, cats, snakes, American crows, other jays, raccoons, opossums, and birds of prey, such as hawks.
Known Predators:
Blue jays form long-lasting, monogamous pair bonds. These bonds usually last until one of the pair dies.
Mating System: monogamous
Blue jays build loose and untidy nests of barks, twigs, leaves, and grasses in trees and shrubs. The female lays three to six eggs at a time. These can be blue, green, or yellow, with brown or grey spots. The eggs must be incubated for 17 to 18 days. This is usually done by female, but in some cases males share in the incubation. Males provide food for females during incubation. Young fledge after 17 to 21 days and leave their natal range about 2 months after fledging. Blue jays may breed in their first year after hatching. (Zims 1956, Reilly 1968)
Breeding interval: In the north, only one brood per year may be produced. In southern regions, however, Blue Jays may raise two broods each year.
Breeding season: Blue Jays breed from March through July.
Range eggs per season: 3 to 6.
Average time to hatching: 17 days.
Range fledging age: 17 to 21 days.
Average time to independence: 3 months.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 17 days.
Average eggs per season: 4.
Both males and females feed their nestlings. Young are able to feed themselves three weeks after they leave the nest, but stay with their parents for around two months after fledging.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
Die Blougaai (Cyanocitta cristata) is 'n sangvoël inheems aan Noord-Amerika. Hulle het opvallende laventelblou vere op die kop en rug. Vere op die onderlyf is gebroke wit. Hulle het 'n swart kraag om die nek en word ongeveer 30 cm lank.[2]
Die blougaai kom oor 'n groot deel van die oostelike helfte van die Verenigde State van Amerika voor. Hulle is talryk in gemengde bos, maar is ook algemeen in parke en tuine.
Blougaaie is omnivore wat 'n verskeidenheid voedselsoorte benut. Hulle vreet onder andere sade, bessies, grondboontjies en brood, maar ook vleis, eiers en klein ongewerwelde diertjies.
Modder word gebruik om die nes in 'n geskikte boom of groot struik te bou. Beide die mannetjie en die wyfie bou saam aan hul nes. Daarna lê die wyfie haar eiers wat na 16 tot 18 dae uitbroei. Hulle maak die kuikens saam groot.
Blougaai, subspesie Cyanocitta cristata cristata in Noord-Carolina
Subspesie C. c. cyanotephra in DeSoto Nasionale natuurlewe-toevlugsoord, Iowa
Subspesie C. c. semplei in Collier County, Florida
Subspesie C. c. bromia in Muskoka-mere, Ontario
Die Blougaai (Cyanocitta cristata) is 'n sangvoël inheems aan Noord-Amerika. Hulle het opvallende laventelblou vere op die kop en rug. Vere op die onderlyf is gebroke wit. Hulle het 'n swart kraag om die nek en word ongeveer 30 cm lank.
Les especies d'aves con nome común en llingua asturiana márquense como NOA. En casu contrariu, conséñase'l nome científicu o de la SEO.
'''Cyanocitta cristata ye un córvidu América del Norte norteamericanu.
La so plumaxe ye predominantemente azul de mediu cuerpu pa enriba, de la cabeza a lo cabero. Tien una cresta pronunciada. El color camuda a negru, celeste y con llistes blanques nes rémige y los caudales. Per debaxo ye blancu, con un collar negru alredor del pescuezu y los llaos de la cabeza, y cola cara blanca.
Como n'otres aves azulaes, la coloración del glayu azul nun deriva de pigmentos, sinón que ye la resultancia de la refraición de la lluz debío a la estructura interna de les plumes; si entartalla una de les plumes la coloración azul sume, pos la estructura foi destruyida. Esto llámase coloración estructural.
El cantar paecer al d'otros córvidos en que ye bien variáu, pero'l soníu más común ye la voz d'alarma, que ye un berru ruidosu, cuasi como'l d'una gavilueta. Tamién emiten un agudu yaie-yaie, que la so frecuencia aumenta a midida que l'ave escítase.
Ocupa gran parte del este de Norteamérica, dende Terranova hasta Florida, llegando pol suroeste de la so distribución hasta Texas, y a Coloráu pol noroeste. Al oeste de les Predreses ye reemplazáu pol glayu de Steller. Tamién hai exemplares nel estáu mexicanu de Tamaulipas que se destribuyen na Reserva de la Biósfera El Cielu.
Anque'l glayu azul polo xeneral permanez tol añu na so área de distribución, delles poblaciones norteñas migren a partir sur de la distribución pel hibiernu (migren de día).
Alcuéntrase sobremanera en montes mistos (qu'inclúin l'haya americana y delles especies de carbayu), pero tamién ye visible en parques y xardinos de delles ciudaes.
Busca la so comida tantu nel suelu como nos árboles, y consume práuticamente tou tipu d'alimentos vexetales y animales, tales como abiyotes, fayucos, granes d'herbales, granos, frutos, bayes, cacagüeses, pan, carne, güevos y pitucos d'otres aves, munchos tipos d'invertebraos, basura de los parques y alimentu pa páxaros.
El so comportamientu agresivu nos cebadorios de páxaros, según la so mala reputación como destructor de niales y güevos d'otros páxaros fixeron que de cutiu el glayu azul nun seya bienveníu en munchos comederos por quien los instalen. La so mala fama pasó a la lliteratura, como na novela de Harper Lee Matar un ruiseñor.
Cualquier árbol o parrotal grande disponible sírvelos p'añerar. Fema y machu collaboren en construyir el nial y alimentar a la niarada, anque solo la fema guara. La puesta sueli ser de 4 o 5 güevos y ye guariada mientres 16 a 18 díes. Xeneralmente los pitucos vuelen ente los 17 y 21 díes.
Típicamente formen pareyes monógames pa tola vida.
El glayu azul ye l'ave de la provincia canadiense de la Islla del Príncipe Dubardu y dio nome al equipu de béisbol Blue Jays de Toronto.
Da nome a los equipos deportivos de les universidaes Creighton y Johns Hopkins.
Blue Jay (glayu azul n'inglés) ye'l nome d'una cai de Los Angeles, conocida por dar nome al cantar «Blue Jay Way», de George Harrison.
Coincidentemente, el glayu azul ye'l logotipu de la rede social Twitter.
La serie animada Regular Show tien un personaxe llamáu Mordecai, que ye un glayu azul.
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. Les especies d'aves con nome común en llingua asturiana márquense como NOA. En casu contrariu, conséñase'l nome científicu o de la SEO. '''Cyanocitta cristata ye un córvidu América del Norte norteamericanu.
Adi mavi zığ-zığ (lat. Cyanocitta cristata) - mavi zığ-zığ cinsinə aid quş növü.
Adi mavi zığ-zığ (lat. Cyanocitta cristata) - mavi zığ-zığ cinsinə aid quş növü.
Ar gegin c'hlas(Daveoù a vank) (liester : kegined glas) a zo ur golvaneg, Cyanocitta cristata an anv skiantel anezhañ.
Tiriad ar gegin c'hlas : tachenn badus tachenn neizhiañ tachenn c'hoañviñ Al labous a vev ar pevar isspesad anezhañ e Norzhamerika :
Meneg anezhi zo en ur gontadenn gant Mark Twain, Jim Baker's Blue Jay Yarn.
Ar gegin c'hlas(Daveoù a vank) (liester : kegined glas) a zo ur golvaneg, Cyanocitta cristata an anv skiantel anezhañ.
La gralla blava americana[1] (Cyanocitta cristata) és un còrvid nord-americà.
El seu plomatge és predominantment blau de mig cos per a dalt, del cap a la cua. Té una cresta pronunciada. El color canvia a negre, celeste i amb llistes blanques en les rémiges i les cabals. Per sota és blanc, amb un collaret negre al voltant del coll i els costats del cap i la cara blanca.
Com en altres aus blavenques, la coloració de la gralla blava no deriva de pigments, sinó que és el resultat de la refracció de la llum deguda a l'estructura interna de les plomes; si s'aixafa una de les plomes la coloració blava desapareix, perquè l'estructura ha estat destruïda. Això es diu coloració estructural.
El cant s'assembla a altres còrvids perquè és molt variat, però el so més comú n'és la veu d'alarma, que és un crit sorollós, gairebé com el d'una gavina. També emeten un agut iaie-iaie la freqüència del qual augmenta a mesura que l'au es veu més excitada.
Ocupa gran part de l'est d'Amèrica del Nord des de Terranova fins a Florida: arriba pel sud-oest fins a Texas i a Colorado pel nord-oest de la seva distribució. Es troba sobretot en boscos mixts, incloent-hi el faig americà i diverses espècies de roure, però també és visible en parcs i jardins d'algunes ciutats. A l'oest de les Rocoses és reemplaçat per la garsa de Steller.
Encara que aquest ocell roman en general tot l'any a la seva àrea de distribució, algunes poblacions del nord migren a la part sud de la distribució a l'hivern. Migren de dia.
La gralla blava americana (Cyanocitta cristata) és un còrvid nord-americà.
Aderyn a rhywogaeth o adar yw Sgrech las (sy'n enw benywaidd; enw lluosog: sgrechod gleision) a adnabyddir hefyd gyda'i enw gwyddonol Cyanocitta cristata; yr enw Saesneg arno yw Blue jay. Mae'n perthyn i deulu'r Brain (Lladin: Corvidae) sydd yn urdd y Passeriformes.[1]
Talfyrir yr enw Lladin yn aml yn C. cristata, sef enw'r rhywogaeth.[2] Mae'r rhywogaeth hon i'w chanfod yng Ngogledd America.
Mae'r sgrech las yn perthyn i deulu'r Brain (Lladin: Corvidae). Dyma rai o aelodau eraill y teulu:
Rhestr Wicidata:
rhywogaeth enw tacson delwedd Brân America Corvus brachyrhynchos Brân bigfain Corvus enca
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Aderyn a rhywogaeth o adar yw Sgrech las (sy'n enw benywaidd; enw lluosog: sgrechod gleision) a adnabyddir hefyd gyda'i enw gwyddonol Cyanocitta cristata; yr enw Saesneg arno yw Blue jay. Mae'n perthyn i deulu'r Brain (Lladin: Corvidae) sydd yn urdd y Passeriformes.
Talfyrir yr enw Lladin yn aml yn C. cristata, sef enw'r rhywogaeth. Mae'r rhywogaeth hon i'w chanfod yng Ngogledd America.
Sojka chocholatá (Cyanocitta cristata) je nejhojnějším a nejrozšířenějším druhem sojky v Severní Americe.[3]
Dorůstá 22–30 cm, v rozpětí křídel měří 34–43 cm a váží 70-100 g, samci jsou přitom o něco větší než samice.[4] Svrchu je převážně modrá s bílými skvrnami a černými pruhy na křídlech a ocase. Spodinu těla má světlou s o něco tmavším zbarvením na hrudi, kde má také výrazný černý pruh, který se táhne až po temeno. Tmavého zbarvení jsou též končetiny, oči a zobák. Výrazným znakem je také její chocholka na hlavě, kterou vztyčuje při vzrušení nebo vyplašení.[5]
Její areál rozšíření zasahuje od jižní Kanady přes střed a východ Spojených států až po Floridu a severovýchod Texasu. Je částečně tažná. Vyskytuje se v celé řadě stanovišť. Preferuje přitom smíšené, bukové a dubové lesy, ale vyskytuje se též v lesích jehličnatých, v parcích i v blízkosti lidských obydlí.[4]
Sojka chocholatá není rychlým letcem (dosahuje rychlosti zhruba 32–40 km/h)[6] a proto bývá na otevřených prostranstvích, kde jí hrozí velké nebezpečí ze strany dravců, velmi ostražitá. Sama však bývá často agresivní k jiným menším ptákům. Po potravě, kterou tvoří různé plody (žaludy, bukvice), semena, malí bezobratlí a v malé míře i ptačí vejce a mláďata,[5] pátrá jak na zemi, tak na stromech. Je zpravidla monogamní. Hnízdo z větví a malých kořenů, následně vystlané peřím, mechem a jiným rostlinným materiálem, staví oba rodiče na stromě nebo na velkém keři. V jedné snůšce je 4-5 vajec, na jejichž 16-18 denní inkubaci se podílí samotná samice. O mláďata, která jsou opeřena ve věku 17-21 dnů, pak následně pečují oba rodiče.[7]
Obrázky, zvuky či videa k tématu sojka chocholatá ve Wikimedia Commons
Galerie sojka chocholatá ve Wikimedia Commons
Sojka chocholatá (Cyanocitta cristata) je nejhojnějším a nejrozšířenějším druhem sojky v Severní Americe.
Der Blauhäher (Cyanocitta cristata) ist eine Singvogelart aus der Familie der Rabenvögel (Corvidae). Dieser Schopfhäher ist im östlichen Nordamerika weitverbreitet und einer der farbenprächtigsten Vögel in dieser Region.[1]
Der 24 bis 30 cm lange Blauhäher hat eine Flügellänge von etwa 13 bis 15 cm und wird 65 bis 109 g schwer. Ihn kennzeichnen der blaue Rücken, eine kurze Haube, ein schwarzes Halsband, ein blau-schwarz-weiß gebändertes Flügelmuster und ein schmal dunkel gebänderter, blauer Schwanz.[1]
Von der Mitte bis zum hinteren Oberkopf trägt der Blauhäher eine moderat ausgebildete Haube. Bei der Nominatform sind die Nasalborsten bläulich weiß, Oberkopf und Haube sind hell violettblau. Unterhalb der Haube verläuft um den Kopf ein schmales schwarzes Band, etwas breiter am hinteren Oberkopf und am schmalsten vom Nacken über Auge und Vorderkopf. Der Streifen verlängert sich zu einem schmalen Halsband welches über die obere Brust verläuft. Die Ohrdecken, ein kurzer Überaugenstreif, die Kehle und die restliche Unterseite sind weißgrau und verwaschen grau, malvenfarbig oder violettgrau. Die bläulichgraue, violettblau verwaschene Oberseite geht zum Bürzel und zu den Oberschwanzdecken hin in ein helles blau über.[1]
Die Flügel sind himmelblau mit einer kräftigen, schwarzen Bänderung an Armschwingen und großen Armdecken. Die Spitzen der Armschwingen und großen Armdecken sind breit weiß gefärbt. Die Unterseite der Flügel sind mit Ausnahme der weißen Spitzen, grau. Der Schwanz ist mittellang und abgestuft. Bis auf das zentrale Steuerfedernpaar sind die Spitzen der Schwanzfedern breit weiß gefärbt, Schwanzunterseite ist, ebenfalls mit Ausnahme der weißen Spitzen, wie die Flügelunterseite grau.[1]
Der Schnabel ist schwarz, die Beine schwärzlich und die Iris schwärzlich braun.[1]
Es gibt keinen deutlichen Sexualdimorphismus, die Männchen sind im Durchschnitt etwas größer als die Weibchen. Juvenile Tiere sind allgemein matter, dumpfer gefärbt. Ihre Oberseite ist grauer, die Flügeldecken nahezu ungebändert, die sonstige Bänderung mit größtem Abstand und die weißen Federspitzen eingeschränkter.[1]
Die vier Unterarten sind einander ähnlich. Sie unterscheiden sich in der Größe und fast unmerklich in der Färbung des Gefieders. Cyanocitta cristata semplei ist die kleinste, Cyanocitta cristata bromia die größte Unterart. Die Variation der Unterarten ist klinal bedingt.[1]
Das Verbreitungsgebiet erstreckt sich über den Osten Nordamerikas von Neufundland, dem südlichen Québec und Zentral Manitoba und Alberta (Kanada) bis Louisiana und das östliche Texas am Golf von Mexiko. Nach Westen reicht die Verbreitung bis in das östliche Wyoming, Nebraska, das östliche Colorado bis in das westliche Texas. Im westlichen Teil Nordamerikas bis zur Pazifikküste findet sich dagegen der dem Blauhäher nahe verwandte Diademhäher (Cyanocitta stelleri, engl. Steller’s Jay), mit dem der Blauhäher gelegentlich hybridisiert.[1]
Im Englischen wird der Vogel Blue Jay genannt. Der Blauhäher ist ein Teilzieher, nur die nördlichsten Populationen ziehen im Winter nach Süden. Er ist Bewohner von Misch- und Laubwäldern, insbesondere wenn Rodungen vorhanden sind. Auch in Parks und Gärten in Städten ist er anzutreffen.[1]
Der Blauhäher lebt gewöhnlich in Paaren, bildet aber auch nach der Brutsaison kleine Schwärme. Beim Vogelzug können sich 100 und mehr Exemplare zusammenfinden. Er verfügt, neben dem typischen, zwei- bis dreimal wiederholten „piiieh-piiieh“-Ruf, über ein breites Repertoire an Lauten und kann den Ruf anderer Arten – z. B. des Rotschwanzbussards – nachahmen. Er besucht Futterplätze in Gärten und kann, wenn er nicht gestört wird, außergewöhnlich zutraulich werden. Bei Nachstellung wird er vorsichtig und scheu.[1]
Der Blauhäher sucht in Baumkronen und in der Bodenvegetation nach Nahrung. Diese besteht hauptsächlich aus Nussfrüchten wie Esskastanien, Eicheln und Bucheckern sowie aus Samen. Daneben frisst er Insekten und gelegentlich andere kleine Tiere wie Nestlinge oder kleine Nagetiere, Eier oder Lebensmittelabfälle. Gewöhnlich versteckt er seinen Nahrungsüberschuss in den Spalten der Baumrinde oder im Boden. Dieses Verhalten zeigen aber anscheinend nur die Populationen, die ganzjährig an ihrem Standort bleiben.[1] In einem Wald der Sumpf-Eiche in Virginia wurden mehr als die Hälfte der Eicheln durch Blauhäher wegtransportiert und weitere 20 Prozent an Ort und Stelle gefressen.[2] Durch dieses Verhalten trägt er zur Verbreitung von Bäumen bei.[3] Die postglaziale Wiederbesiedlung Nordamerikas durch Baumarten mit schweren Samen wie Buchen-, Kastanien- und Eichenarten lässt sich nur durch die Verbreitung durch Blauhäher erklären, die die Ausbreitungsdistanz um eine Größenordnung (vom Meter- in den Kilometerbereich) erhöhen[4].
Blauhäher sind monogam und bleiben ein Leben lang zusammen. Beide Elternteile bauen ein unordentliches schalenförmiges Nest aus Zweigen, Gras und Stängeln in einem Baum oder Busch, selten in alten Gebäuden. Das Gelege wird vom Weibchen, ganz selten auch vom Männchen sechzehn bis achtzehn Tage bebrütet. Blauhäher brüten, zumindest im Norden, in der Regel einmal im Jahr. Aber auch zwei erfolgreiche Brutgeschäfte sind nicht selten und auch von ausnahmsweise dritten Bruten wird berichtet. Das Gelege besteht aus zwei bis sechs, gewöhnlich vier bis fünf Eiern. Die Eier sind von blass gelbbrauner bis blass grünlicher Farbe und braun, oliv oder grau gesprenkelt. Nach siebzehn bis einundzwanzig Tagen sind die Jungvögel flügge.[1]
Es werden vier Unterarten unterschieden[1]:
Die Art ist bekannt als eines der Beispiele für Werkzeuggebrauch bei Tieren[5]. Ein in Gefangenschaft gehaltener Blauhäher wurde dabei beobachtet, wie er wiederholt Streifen von umherliegenden Zeitungen abriss und diese zusammendrehte, um Nahrungsbröcken heranzuziehen, die außerhalb des Käfigs außer Reichweite verstreut lagen.
Der Blauhäher (Blue Jay) ist Namensgeber und Maskottchen des kanadischen Major-League-Baseball-Teams Toronto Blue Jays.
Der Blauhäher ist Namensgeber und Logo der Java-Programmierumgebung BlueJ.
Der Blauhäher ist eine Inspiration des Cartoon-Charakters "Mordecai" in der Serie Regular Show.
Ein Gedicht von Marcel Beyer heißt Mein Blauhäher.[6]
In der Folge 5.9 der Serie The Big Bang Theory hat Sheldon Angst vor einem Vogel, den er mehrfach als Blauhäher bezeichnet. Tatsächlich handelt es sich hierbei um einen Langschwanzhäher der Art Schwarzkehl-Elsterhäher (Calocitta colliei), auch Schwarzwangenhäher genannt.[7]
Auf dem Beatles-Album Magical Mystery Tour erschien ein Lied namens Blue Jay Way von George Harrison.
Der Blauhäher (Cyanocitta cristata) ist eine Singvogelart aus der Familie der Rabenvögel (Corvidae). Dieser Schopfhäher ist im östlichen Nordamerika weitverbreitet und einer der farbenprächtigsten Vögel in dieser Region.
De blauwe gaai (Latien: Cyanocitta cristata) is n Noord-Amerikaanse soort gaai mit een opvallend lavendelblauw verenkleed op de rogge en de kop. De veren op t onderlief bin ebreuken wit, en rond de hals hef e n zwarte krage.
De blauwe gaai kömp in n groot deel van de oostelike helfte van de Verenigden Staoten veur. Veural in emengd bos kömp e vake veur, mer daornaost kömp e veur in parken en tunen.
t Dieet van de blauwe gaai is arg aofwisselend. Op t menu staon onder aandere ekels, zaojen, bezen, apenoetjes en brood, mer oek vleis, eiers en kleine ongewarvelden.
Elke geschikte boom of grote struke kan gebruukt wörden veur t maken van een nest. t Mannetjen en t wiefjen warken mee an de bouw dervan, daornao zal t wiefjen de eiers in zo'n 16 tot 18 dagen uutbreujen. Vaor en moene brengen samen de kukens groot. Nao dree weken scheit moene der mee uut en mutten de jongen veur der eigen gaon zörgen.
Blauwe gaai, ondersoorte Cyanocitta cristata cristata in Noord-Carolina
Ondersoorte C. c. cyanotephra in DeSoto National Wildlife Refuge, Iowa (staot)
Ondersoorte C. c. semplei in Collier County Florida (staot)
Ondersoorte C. c. bromia in Muskoka Lakes, Ontario
The Blue Jay (Cyanocitta cristata) is a passerine bird in the faimily Corvidae, native tae North Americae. It is resident throu maist o eastren an central Unitit States an soothren Canadae, altho wastren populations mey be migratory. It breeds in baith deciduous an coniferous forests, an is common near an in residential auries. It is predominately blue wi a white chest an unnerparts, an a blue crest. It haes a black, U-shaped collar aroond its neck an a black mairch behind the crest. Sexes are seemilar in size an plumage, an plumage daes nae vary throughoot the year. Fower subspecies o the Blue Jay are recognised.
The Blue Jay mainly feeds on nits an seeds sic as acorns, saft fruits, arthropods, an occasionally smaa vertebrates. It teepically gleans fuid frae trees, shrubs, an the grund, tho it whiles hawks insects frae the air. It bigs an open cup nest in the branches o a tree, which baith sexes pairteecipate in constructin. The clutch can contain twa tae seiven eggs, which are blueish or licht broun wi broun spots. Young are altricial, an are broodit bi the female for 8–12 days efter hatchin. Thay mey remain wi thair parents for ane tae twa months.
The bird's name derives frae its noisy, garrulous naitur.[2] It is whiles cried a "jaybird".[3]
The Blue Jay measurs 22–30 cm (9–12 in) frae bill tae tail an wechts 70–100 g (2.5–3.5 oz), wi a wingspan o 34–43 cm (13–17 in).[4][5] Jays frae Connecticut averaged 92.4 g (3.26 oz) in mass, while jays frae soothren Floridae averaged 73.7 g (2.60 oz).[6][7] Thare is a pronoonced crest on the heid, a croun o feathers, which mey be raised or lawered accordin tae the bird's muid. When excitit or aggressive, the crest mey be fully raised. When frichtened, the crest bristles ootwards, brushlik. When the bird is feedin amang ither jays or restin, the crest is flattened tae the heid.[8]
Its plumage is lavender-blue tae mid-blue in the crest, back, wings, an tail, an its face is white. The unnerside is off-white an the neck is collared wi black which extends tae the sides o the heid. The wing primaries an tail are strangly barred wi black, sky-blue an white. The bill, legs, an een are aw black. Males an females are nearly identical, but the male is a little lairger.[5][9]
As wi maist ither blue-hued birds, the Blue Jay's colouration is nae derived frae pigments but is the result of licht interference due tae the internal structur o the feathers;[10] if a blue feather is crushed, the blue disappears as the structur is destroyed.[4] This is referred tae as structural coloration.
The Blue Jay occurs frae soothren Canadae throu the eastren an central USA sooth tae Florida an northeastren Texas. The wastren edge o the range stops whaur the arid pine forest an scrub habitat o the closely relatit Steller's jay (C. stelleri) begins. Recently, the range o the Blue Jay haes extendit northwastwards sae that it is nou a rare but regularly seen winter veesitor alang the northren US an soothren Canadian Pacific Coast.[4] As the twa species' ranges nou owerlap, C. cristata mey whiles hybridize wi Steller's jay.[11]
The northrenmaist subspecies C. c. bromia is migratory, subject tae necessity. It mey withdraw several hundrit kilometers sooth in the northrenmaist pairts o its range. Thoosands o Blue Jays hae been observed tae migrate in flocks alang the Great Lochs an Atlantic coasts. It migrates during the daytime, in loose flocks o 5 tae 250 birds. Much aboot thair migratory behavior remains a mystery. Some are present throughoot winter in aw pairts o thair range. Young jays mey be mair likely tae migrate nor adults, but mony adults an aa migrate. Some individual jays migrate sooth ane year, stay north the next winter, an then migrate sooth again the next year. Tae date, no ane haes concretely wirked oot why thay migrate whan thay dae. Likely, it is relatit tae wather condeetions an hou abundant the winter fuid soorces are, which can determine whether ither northren birds will muive sooth.[12]
The Blue Jay occupies a variety o habitats within its lairge range, frae the pine wids o Florida tae the spruce-fir forests o northren Ontario. It is less abundant in denser forests, preferrin mixed widlands wi aiks an beeches.[8] It haes expertly adaptit tae human activity, occurrin in pairks an residential auries, an can adapt tae wholesale deforestation wi relative ease if human activity creates ither means for the jays tae get bi.[13]
Fower subspecies are generally acceptit, tho the variation within this species is rather subtle an essentially clinal. No firm boundaries can be drawn atween the inland subspecies. The ranges o the coastal races are better deleemitit.[9]
The bricht Cyanocitta cristata cristata in Johnston Coonty, North Carolina
Cyanocitta c. cristata
Ash, North Carolina
A C. c. cyanotephra in DeSoto Naitional Wildlife Refuge, Iowa
C. c. semplei, a smaa form, in Collier Coonty, Florida
C. c. bromia in Muskoka Lakes, Ontario
C. c. bromia, Young Northren Blue Jay in Ontario, Canadae
C. c. bromia, Northren Blue Jay in Ontario, Canadae
The Blue Jay is a noisy, bold an aggressive passerine. It is a moderately slow flier (roughly 32–40 km/h (20–25 mph)) whan unprovoked.[14] It flies wi body an tail held level, wit slow wing beats. Due tae its slow flyin speeds, this species maks easy prey for hawks an houlets whan flyin in open auries. Virtually aw the raptorial birds sympatric in distribution wi the Blue Jay mey predate it, especially swift bird-huntin specialists sic as the Accipiter hawks. Diverse predators mey predate jay eggs an young up tae thair fledging stage, includin tree squirrels, snakes, cats, crows, raccoons, opossums, ither jays an possibly mony o the same birds o prey who attack adults.[15]
The Blue Jay can be beneficial tae ither bird species, as it mey chase predatory birds, sic as hawks an houlets, an will scream if it sees a predator within its territory. It haes an aa been kent tae soond an alarm cry whan hawks or ither dangers are near, an smawer birds eften recognise this cry an hide themselves away accordinly. It mey occasionally impersonate the crys o raptors, especially those o the Reid-tailed an Reid-shouldered Hawks, possibly tae test if a hawk is in the vicinity, tho an aa possibly tae scare off ither birds that mey compete for fuid soorces.[12] It mey an aa be aggressive towards humans who come close tae its nest, an if an houlet roosts near the nest durin the daytime the Blue Jay mobs it till it taks a new roost. Houiver, Blue Jays hae an aa been kent tae attack or kill ither smawer birds an sleepin, foliage-roostin bat species sic as Lasiurus borealis.[16] Jays are very territorial birds, an thay will chase ithers frae a feeder for an easier meal. Addeetionally, the Blue Jay mey raid ither birds' nests, stealin eggs, chicks, an nests. Houiver, this mey nae be as common as is teepically thocht, as anly 1% o fuid matter in ane study wis compromised bi birds.[12] Despite this, ither passerines mey still mob jays who come within thair breedin territories.
Blue Jays, lik ither corvids, are heichly curious an are considered intelligent birds. Young individuals playfully snatch brichtly coloured or reflective objects, sic as bottle caps or pieces o aluminum foil, an cairy them aroond till thay lose interest.[16] While nae confirmed tae hae engaged in tuil uise in the wild, blue jays in captivity hae been observed uisin strips o newspaper as tuils tae obtain fuid,[12][17] while captive fledglins hae been observed attemptin tae open the duir tae thair cages [18]
Blue Jays hae strange black bills which thay uise for cracking nuts an acorns, uisually while holding them wi thair feet, an for eatin corn, grains an seeds. Its fuid is soucht baith on the grund an in trees an includes virtually aw kent types o plant an ainimal soorces, sic as acorns an beech mast, weed seeds, grain, fruits an ither berries, peanuts, breid, meat, smaa invertebrates o mony types, scraps in toun pairks, bird-table fuid an rarely eggs an nestlins.[12] Blue Jays will whiles cache fuid, tho tae whit extent differs widely amang individuals.[19] Altho seemingly contentious in thair general behavior, Blue jays are frequently subservient tae ither medium-sized birds who veesit bird-feeders. In Florida, Blue jays wur dominatit at feeders bi Eastren gray squirrels, Florida Scrub-Jays, Common Grackles an Reid-heidit Widpeckers, aw o which wur occasionally observed tae aggressively prevent the jays frae feedin.[12]
The matein saison begins in mid-Mairch, peaks in mid-Aprile tae Mey, an extends intae Julie. Ony suitable tree or lairge bush mey be uised for nestin, tho an evergreen is preferred. The nest is preferentially biggit at a hicht in the trees o 3 tae 10 m (9.8 tae 32.8 ft). It is cup-shaped an componed o twigs, smaa ruits, bark strips, moss, ither plant material, cloth, paper, an feathers, wi occasional mud addit tae the cup.
Blue Jays are nae very picky aboot nestin locations. If no better place is available – e.g. in a hivily deforestit aurie – thay will even uise places lik the lairge mailboxes teepical o the rural Unitit States.[13] Thay an aa appropriate nests o ither mid-sized sangbirds as lang as thir are placed in suitable spots; American robin nests are commonly uised bi Blue Jays, for ensaumple.
Blue Jays teepically form monogamous pair bonds for life. Baith sexes big the nest an rear the young, tho anly the female bruids them. The male feeds the female while she is bruidin the eggs. Thare are uisually atween 3 an 6 (averagin 4 or 5) eggs laid an incubatit ower 16–18 days. The young fledge uisually atween 17–21 days efter hatchin.[16]
Efter the juveniles fledge, the faimily travels an forages thegither till early faw, whan the young birds disperse tae avoid competeetion for fuid during the winter. Sexual maturity is reached efter ane year o age. Blue jays hae been recordit tae live for mair nor 26 years in captivity an ane wild jay wis foond tae hae been aroond 17 an a hauf years auld.[20] A mair common lifespan for wild birds that survive tae adulthuid is aroond 7 years.[citation needit] Beyond predation an the occasional collision wi man-made objects, a common cause o mortality in recent decades haes been the Wast Nile Virus, which corvids as a whole seem especially subceptible tae. Houiver, despite several major local declines, oweraw Blue Jays hae nae seemed tae hae been depletit bi the disease.[15]
Blue Jays can mak a lairge variety o soonds, an individuals mey vary perceptibly in thair cryin style. Lik ither corvids, thay mey learn tae mimic human speech. Blue Jays can an aa copy the cries o local hawks sae well that it is whiles difficult tae tell which it is.[21] Thair vyce is teepical o maist jays in bein varied, but the maist commonly recognised soond is the alarm cry, which is a loud, almaist gull-lik scream. Thare is an aa a heich-pitched jayer-jayer cry that increases in speed as the bird acomes mair agitatit. This parteecular cry can be easily confused wi the chickadee's sang acause o the slow stairtin chick-ah-dee-ee. Blue Jays will uise thir crys tae baund thegither tae mob potential predators sic as hawks an drive them away frae the jays' nests.
Blue Jays an aa hae quiet, almist subliminal calls which thay uise amang themselves in proximity. Ane o the maist distinctive crys o this teep is eften referred tae as the "rusty pump" owin tae its squeaky resemblance tae the soond o an auld haund-operatit watter pump. The Blue Jay (an ither corvids) are distinct frae maist ither sangbirds for uisin thair cry as a sang.
In auld African-American folklore o the soothren Unitit States the blue jay wis held tae be a servant o the Devil, an "wis nae encoontered on a Friday as he wis fetchin sticks doun tae Hell; furthermair, he wis so happy an chirpy on a Setturday as he wis relieved tae return frae Hell".[22]
The blue jay wis adoptit as the team seembol o the Toronto Blue Jays Major League Baseball team, as well as some o thair minor-league affiliates. Thair mascot is Ace, an aa a blue jay.
The blue jay is the offeecial bird o the province o Prince Edward Island in Canadae.
Mordecai, an anthropomorphic blue jay, is ane o the main chairacters o the cartuin series Regular Show.
The Blue Jay is featurt in Mark Twain's "A Tramp Abroad", Chapter 3 "Baker,s Blue-Jay Yarn".
The Blue Jay (Cyanocitta cristata) is a passerine bird in the faimily Corvidae, native tae North Americae. It is resident throu maist o eastren an central Unitit States an soothren Canadae, altho wastren populations mey be migratory. It breeds in baith deciduous an coniferous forests, an is common near an in residential auries. It is predominately blue wi a white chest an unnerparts, an a blue crest. It haes a black, U-shaped collar aroond its neck an a black mairch behind the crest. Sexes are seemilar in size an plumage, an plumage daes nae vary throughoot the year. Fower subspecies o the Blue Jay are recognised.
The Blue Jay mainly feeds on nits an seeds sic as acorns, saft fruits, arthropods, an occasionally smaa vertebrates. It teepically gleans fuid frae trees, shrubs, an the grund, tho it whiles hawks insects frae the air. It bigs an open cup nest in the branches o a tree, which baith sexes pairteecipate in constructin. The clutch can contain twa tae seiven eggs, which are blueish or licht broun wi broun spots. Young are altricial, an are broodit bi the female for 8–12 days efter hatchin. Thay mey remain wi thair parents for ane tae twa months.
The bird's name derives frae its noisy, garrulous naitur. It is whiles cried a "jaybird".
Ang Cyanocitta cristata (Ingles: blue jay; Kastila: arrendajo azul o urraca azul) ay isang ibong kasapi sa pamilyang Corvidae o mga korbido (mga jay sa Ingles, bigkas: /dzey/, mga ibong salta o bagito) na katutubo sa Hilagang Amerika. Kabilang ito sa bughaw na mga korbidong Kanadyano o Amerikano na, sa piling ng mga korbido, ay hindi kalapit na kaugnayan ng iba pang mga korbido. Madaling makibagay ito sa kanilang kapaligiran, agresibo, omniboro, at nananakop ng bagong mga kapaligiran sa loob ng maraming mga dekada.
Ang lathalaing ito na tungkol sa Ibon ay isang usbong. Makatutulong ka sa Wikipedia sa nito.
Ang Cyanocitta cristata (Ingles: blue jay; Kastila: arrendajo azul o urraca azul) ay isang ibong kasapi sa pamilyang Corvidae o mga korbido (mga jay sa Ingles, bigkas: /dzey/, mga ibong salta o bagito) na katutubo sa Hilagang Amerika. Kabilang ito sa bughaw na mga korbidong Kanadyano o Amerikano na, sa piling ng mga korbido, ay hindi kalapit na kaugnayan ng iba pang mga korbido. Madaling makibagay ito sa kanilang kapaligiran, agresibo, omniboro, at nananakop ng bagong mga kapaligiran sa loob ng maraming mga dekada.
Nâ-chhiok (ha̍k-miâ: Cyanocitta cristata; Eng-miâ: blue jay), sī chi̍t khoán seng-oa̍h tī Pak Bí-chiu ê Corvidae kho chiáu-lūi.
Nâ-chhiok (ha̍k-miâ: Cyanocitta cristata; Eng-miâ: blue jay), sī chi̍t khoán seng-oa̍h tī Pak Bí-chiu ê Corvidae kho chiáu-lūi.
{{{assessors}}} (2012). Cyanocitta cristata. nî IUCN Siū Ui-hia̍p Bu̍t-chéng Âng Miâ-toaⁿ. IUCN . chih-chiap.Блакі́тная со́йка, паўночнаамэрыка́нская блакітная сойка (Cyanocitta cristata) — сьпеўная птушка. Даўжыня цела каля 28 см, размах крылаў 42 см, важыць каля 52 г. Вызначаецца блакітнай афарбоўкай пер’я на сьпіне, кароткім блакітным хахалком, чорным кальцом вакол шыі, бела-блакітна-чорным узорам на крылах і чорна-белымі палоскамі ўздоўж хваста. Від распаўсюджаны выключна ў Паўночнай Амэрыцы. Жыцьцёвы арэал птушкі прасьціраецца ад усходняга ўзьбярэжжа Паўночнай Амэрыкі праз поўдзень Канады да Мэксыканскае затокі. Папуляцыі поўночных регіёнаў — пералётныя птушкі, якія зімой адлятаюць на поўдзень.
Блакітная сойка — лясны жыхар, але сёньня ўсё часьцей і пераважна ўзімку сустракаецца таксама нападалёку ад сельскагаспадарчых мурогаў, у вёсках, парках і прадмесьцях невялікіх гарадоў. Асобіны паўночнаамэрыканскай сойкі жывуць пераважна парамі альбо невялікімі сямействамі. У пералётны пэрыяд птушкі зьбіраюцца ў вялікія групы. Побач з тыповым піііе-піііе птушка валодае вялікім рэпэртуарам іншых гукаў, пераймае галасы іншых відаў, добра імітуе драпежных птушак. Такім чынам блакітная сойка засьцерагае іншых птушак віда і абараняе свой жыцьцёвы арэал ад ворагаў.
Рэдкі від, занесены ў сьпіс ахоўваных птушак IUCN 2004.
— сховішча мультымэдыйных матэрыялаў
(Даўжыня 03:52) (Даўжыня 01:56)Блакі́тная со́йка, паўночнаамэрыка́нская блакітная сойка (Cyanocitta cristata) — сьпеўная птушка. Даўжыня цела каля 28 см, размах крылаў 42 см, важыць каля 52 г. Вызначаецца блакітнай афарбоўкай пер’я на сьпіне, кароткім блакітным хахалком, чорным кальцом вакол шыі, бела-блакітна-чорным узорам на крылах і чорна-белымі палоскамі ўздоўж хваста. Від распаўсюджаны выключна ў Паўночнай Амэрыцы. Жыцьцёвы арэал птушкі прасьціраецца ад усходняга ўзьбярэжжа Паўночнай Амэрыкі праз поўдзень Канады да Мэксыканскае затокі. Папуляцыі поўночных регіёнаў — пералётныя птушкі, якія зімой адлятаюць на поўдзень.
Блакітная сойка — лясны жыхар, але сёньня ўсё часьцей і пераважна ўзімку сустракаецца таксама нападалёку ад сельскагаспадарчых мурогаў, у вёсках, парках і прадмесьцях невялікіх гарадоў. Асобіны паўночнаамэрыканскай сойкі жывуць пераважна парамі альбо невялікімі сямействамі. У пералётны пэрыяд птушкі зьбіраюцца ў вялікія групы. Побач з тыповым піііе-піііе птушка валодае вялікім рэпэртуарам іншых гукаў, пераймае галасы іншых відаў, добра імітуе драпежных птушак. Такім чынам блакітная сойка засьцерагае іншых птушак віда і абараняе свой жыцьцёвы арэал ад ворагаў.
Рэдкі від, занесены ў сьпіс ахоўваных птушак IUCN 2004.
நீல அழகி (blue jay, Cyanocitta cristata) என்பது கோர்விடே குடும்பத்தைச் சேர்ந்த, தென் அமெரிக்காவை தாயகமாகக் கொண்ட ஒரு பசரின் பறவையாகும்.
நீல அழகி அலகு முதல் வால் வரை 22–30 cm (9–12 in) நீளமுள்ளதும் 70–100 g (2.5–3.5 oz) நிறையுள்ளதும் இறக்கை விரிப்பு அளவு 34–43 cm (13–17 in) கொண்டுமுள்ளது.[2][3] கனெடிகட் பகுதியில் உள்ளது கிட்டத்தட்ட 92.4 g (3.26 oz) நிறையும், தென் புளோரிடா பகுதியில் உள்ளது கிட்டத்தட்ட 73.7 g (2.60 oz) நிறையும் உள்ளது.[4][5] அதன் தலையில் முடி அமைப்பு காணப்படும். பறவையின் மனநிலைக்கு ஏற்ற அது உயர்ந்தோ தாழ்ந்தோ காணப்படும். இது கோபமாக இருக்கும்போது முடி உயர்ந்தும், பயமாக இருக்கும்போது, சிலிர்த்துக் கொண்டும் இருக்கும். மற்றப் பறவைகளுடன் சேர்ந்து உண்ணும்போது அல்லது ஓய்வாக இருக்கும்போது தலையுடன் முடி அமர்ந்து காணப்படும்.[6]
நீல அழகி (blue jay, Cyanocitta cristata) என்பது கோர்விடே குடும்பத்தைச் சேர்ந்த, தென் அமெரிக்காவை தாயகமாகக் கொண்ட ஒரு பசரின் பறவையாகும்.
Otá'tavâho'hé-vé'késo, ve'kêseho-éve.
Mée'e
The blue jay (Cyanocitta cristata) is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are also in Newfoundland, Canada; breeding populations are found across southern Canada. It breeds in both deciduous and coniferous forests, and is common in residential areas. Its coloration is predominantly blue, with a white chest and underparts, and a blue crest; it has a black, U-shaped collar around its neck and a black border behind the crest. Males and females are similar in size and plumage, and plumage does not vary throughout the year. Four subspecies have been recognized.
The blue jay feeds mainly on seeds and nuts, such as acorns, which it may hide to eat later;[2] soft fruits; arthropods; and occasionally small vertebrates. It typically gleans food from trees, shrubs, and the ground, and sometimes hawks insects from the air. Blue jays can be very aggressive to other birds; they sometimes raid nests and have even been found to have decapitated other birds.[3]
It builds an open cup nest in the branches of a tree; both sexes participate. The clutch may be two to seven eggs, which are blueish or light brown with darker brown spots. Young are altricial, and are brooded by the female for 8–12 days after hatching. They may stay with their parents for one to two months.
The name jay derives from the bird's noisy, garrulous nature and has been applied to other birds of the same family, which are also mostly gregarious.[4] Jays are also called jaybirds.[5]
The blue jay was first described as Pica glandaria cærulea cristata in English naturalist Mark Catesby's 1731 publication of Natural History of Carolina, Florida, and the Bahamas.[6] It was later described as Corvus cristatus in Carl Linnaeus' 1758 edition of Systema Naturae.[7] In the 19th century, the jay was described by French ornithologist Charles Lucien Bonaparte in 1838 as Cyanocorax cristatus in A geographical and comparative list of the birds of Europe and North America,[8] and given its modern scientific name Cyanocitta cristata by Hugh Edwin Strickland in 1845.[9] The genus name Cyanocitta derives from the Greek words 'kyaneos' (blue) and the 'kitta' and 'kissa' (chattering bird, jay), and the term 'blue chatterer' refers to the bright blue plumage of the head, nape, back, and tail of the bird. The specific name cristata (crested, tufted) derives from Latin referring to the prominent blue crest of the jay.[10]
The blue jay measures 22–30 cm (9–12 in) from bill to tail and weighs 70–100 g (2.5–3.5 oz), with a wingspan of 34–43 cm (13–17 in).[11][12] Consistent with Bergmann's rule, jays from Connecticut averaged 92.4 g (3.26 oz) in mass, while jays from warmer southern Florida averaged 73.7 g (2.60 oz).[13][14] There is a pronounced crest on the head, a crown of feathers, which may be raised or lowered according to the bird's mood. When excited or aggressive, the crest will be fully raised. When frightened, the crest bristles outwards, brushlike. When the bird is feeding among other jays or resting, the crest is flattened on the head.[15]
Its plumage is lavender-blue to mid-blue in the crest, back, wings, and tail, and its face is white. The underside is off-white and the neck is collared with black which extends to the sides of the head. The wing primaries and tail are strongly barred with black, sky-blue, and white. The bill, legs, and eyes are all black. Males and females are almost identical, but the male is slightly larger.[12][16] The black plumage on its nape, face, and throat varies extensively between individuals; it is believed to assist in recognition between individuals.[12]
As with most other blue-hued birds, the blue jay's coloration is not derived from pigments but is the result of light interference due to the internal structure of the feathers;[17] if a blue feather is crushed, the blue disappears because the structure is destroyed. The actual pigment in its feathers is melanin.[11] This is referred to as structural coloration.
The blue jay occurs from southern Canada (including the southern areas of provinces from Alberta eastward to Quebec and throughout the Atlantic provinces) and throughout the eastern and central United States south to Florida and northeastern Texas. The western edge of the range stops where the arid pine forest and scrub habitat of the closely related Steller's jay (C. stelleri) begins, generally in the eastern foothills of the Rocky Mountains. Recently, the range of the blue jay has extended northwestwards so that it is now a rare but regularly seen winter visitor along the northern US and southern Canadian Pacific Coast.[11] As the two species' ranges now overlap, C. cristata may sometimes hybridize with Steller's jay.[18] The increase in trees throughout the Great Plains during the past century due to fire suppression and tree planting facilitated the western range expansion of the blue jay[19][20] as well as range expansions of many other species of birds.[21][22][23] From 1966 to 2015, the Blue Jay experienced a population decline along the Atlantic coast, but a greater than 1.5% annual population increase throughout the northern part of its range, including Labrador, Nova Scotia, southern Quebec, and southern Manitoba.[24]
The northernmost subspecies C. c. bromia is migratory, subject to necessity. It may withdraw several hundred kilometers south in the northernmost parts of its range. Thousands of blue jays have been observed to migrate in flocks along the Great Lakes and Atlantic coasts. It migrates during the daytime, in loose flocks of 5 to 250 birds. Much about their migratory behavior remains a mystery. Some are present throughout winter in all parts of their range. Young jays may be more likely to migrate than adults, but many adults also migrate. Some individual jays migrate south one year, stay north the next winter, and then migrate south again the next year. To date, no one has concretely worked out why they migrate when they do. Likely, it is related to weather conditions and how abundant the winter food sources are, which can determine whether other northern birds will move south.[25]
The blue jay occupies a variety of habitats within its large range, from the pine woods of Florida to the spruce-fir forests of northern Ontario. It is less abundant in denser forests, preferring mixed woodlands with oaks and beeches.[15] It has expertly adapted to human activity, occurring in parks and residential areas, and can adapt to wholesale deforestation with relative ease if human activity creates other means for the jays to get by.[26]
Four subspecies are generally accepted, though the variation within this species is rather subtle and essentially clinal. No firm boundaries can be drawn between the inland subspecies. The ranges of the coastal races are better delimited.[16]
The blue jay is a noisy, bold, and aggressive passerine. It is a moderately slow flier (roughly 32–40 km/h (20–25 mph)) when unprovoked.[27] It flies with body and tail held level, with slow wing beats. Its slow flying speeds make this species easy prey for hawks and owls when it flies in open areas. Virtually all the raptorial birds sympatric in distribution with the blue jay may prey upon it, especially swift bird-hunting specialists such as the Accipiter hawks. Diverse predators may prey on jay eggs and young up to their fledgling stage, including tree squirrels, snakes, cats, crows, raccoons, opossums, other jays and possibly many of the same birds of prey who attack adults.[28]
The blue jay can be beneficial to other bird species, as it may chase predatory birds, such as hawks and owls, and will scream if it sees a predator within its territory. It has also been known to sound an alarm call when hawks or other dangers are near, and smaller birds often recognize this call and hide themselves away accordingly. It may occasionally impersonate the calls of raptors, especially those of the red-tailed and red-shouldered hawks, possibly to test if a hawk is in the vicinity, though also possibly to scare off other birds that may compete for food sources.[25] It may also be aggressive towards humans who come close to its nest, and if an owl roosts near the nest during the daytime the blue jay mobs it until it takes a new roost.[29] However, blue jays have also been known to attack or kill other smaller birds, and foliage-roosting bat species such as Eastern red bats.[30] Jays are very territorial birds, and they will chase others from a feeder for an easier meal. Additionally, the blue jay may raid other birds' nests, stealing eggs, chicks, and nests. However, this may not be as common as is typically thought, as only 1% of food matter in one study was bird material.[25] Despite this, other passerines may still mob jays who come within their breeding territories.
When a blue jay is agitated or angry, the blue crest atop its head will rise. It will lower when the bird is relaxed or calm.[31]
Blue jays, like other corvids, are highly curious and are considered intelligent birds. Young individuals playfully snatch brightly coloured or reflective objects, such as bottle caps or pieces of aluminum foil, and carry them around until they lose interest.[29] While not confirmed to have engaged in tool use in the wild, blue jays in captivity have been observed using strips of newspaper as tools to obtain food,[25][32] while captive fledglings have been observed attempting to open the doors of their cages.[33]
Blue jays are omnivorous, but the Audubon Society estimates that 75% of their diet is vegetable matter.[34] They have strong black bills which they use for cracking nuts, usually while holding them with their feet, and for eating corn, grains and seeds. Blue jays particularly love to eat peanuts in the shell.[35] Its food is sought both on the ground and in trees and includes virtually all known types of plant and animal sources, such as acorns and beech mast, weed seeds, grain, fruits and other berries, peanuts, bread, meat, small invertebrates of many types, scraps in town parks, bird-table food and rarely eggs and nestlings.[25] Blue jays will sometimes cache food, though to what extent differs widely among individuals.[36] Although seemingly contentious in their general behavior, blue jays are frequently subservient to other medium-sized birds who visit bird-feeders. In Florida, blue jays were dominated at feeders by eastern gray squirrels, Florida scrub-jays, common grackles and red-headed woodpeckers, all of which were occasionally observed to aggressively prevent the jays from feeding.[25]
The mating season begins in mid-March, peaks in mid-April to May, and extends into July. Any suitable tree or large bush may be used for nesting, though an evergreen is preferred. The nest is preferentially built at a height in the trees of 3 to 10 m (10 to 33 ft). It is cup-shaped and composed of twigs, small roots, bark strips, moss, other plant material, cloth, paper, and feathers, with occasional mud added to the cup.
Blue jays are not very picky about nesting locations. If no better place is available – e.g. in a heavily deforested area – they will even use places like the large mailboxes typical of the rural United States.[26] They also appropriate nests of other mid-sized songbirds as long as these are placed in suitable spots; American robin nests are commonly used by blue jays, for example.
Blue jays typically form monogamous pair bonds for life. Both sexes build the nest and rear the young, though only the female broods them. The male feeds the female while she is brooding the eggs. There are usually between 3 and 6 (averaging 4 or 5) eggs laid and incubated over 16–18 days. The young fledge usually between 17 and 21 days after hatching.[29]
After the juveniles fledge, the family travels and forages together until early fall, when the young birds disperse to avoid competition for food during the winter. Sexual maturity is reached after one year of age. The oldest known wild, banded Blue Jay was at least 26 years, 11 months old when it was found dead after being caught in fishing gear. It had been banded in the Newfoundland/Labrador/St. Pierre et Miquelon area in 1989 and was found there in 2016.[37] Another wild jay was found to have been around 17+1⁄2 years old.[38] A more common lifespan for wild birds that survive to adulthood is around 7 years.[39] Beyond predation and the occasional collision with man-made objects, a common cause of mortality in recent decades has been the West Nile virus, to which corvids as a whole seem especially susceptible. However, despite several major local declines, overall blue jays have not seemed to have been depleted by the disease.[28]
Blue jays can make a large variety of sounds, and individuals may vary perceptibly in their calling style. Like other corvids, they may learn to mimic human speech. Blue jays can also copy the cries of local hawks so well that it is sometimes difficult to tell which it is.[40] Their voice is typical of most jays in being varied, but the most commonly recognized sound is the alarm call, which is a loud, almost gull-like scream. There is also a high-pitched jayer-jayer call that increases in speed as the bird becomes more agitated. This particular call can be easily confused with the chickadee's song because of the slow-starting chick-ah-dee-ee. Blue jays will use these calls to band together to mob potential predators such as hawks and drive them away from the jays' nests.
Blue jays also have quiet, less noticeable calls which they use among themselves in proximity. One of the most distinctive calls of this type is often referred to as the "rusty pump" owing to its squeaky resemblance to the sound of an old hand-operated water pump. The blue jay (and other corvids) are distinct from most other songbirds for using their call as a song.
In old African-American folktales of the southern United States, the blue jay was a significant metaphysical creature. In some tales, the blue jay was credited with making the earth "when all de worl' was water" by bringing the first "grit" or "dirt." In other tales the blue jay was temporarily conscripted as a servant of the devil and would not be seen on Friday as it was gathering twigs to furnish hell's kindling and give fire to wicked men on Earth; relieved from duty on Saturday, its song for the day was abundant and joyous.[41][42]
The blue jay was adopted as the team symbol of the Toronto Blue Jays Major League Baseball team, as well as some of their minor league affiliates. Their mascot, Ace, is an anthropomorphic blue jay. The blue jay is also the official mascot for Johns Hopkins University, Elmhurst University, and Creighton University. It is also the provincial bird of the province of Prince Edward Island in Canada.
The blue jay (Cyanocitta cristata) is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are also in Newfoundland, Canada; breeding populations are found across southern Canada. It breeds in both deciduous and coniferous forests, and is common in residential areas. Its coloration is predominantly blue, with a white chest and underparts, and a blue crest; it has a black, U-shaped collar around its neck and a black border behind the crest. Males and females are similar in size and plumage, and plumage does not vary throughout the year. Four subspecies have been recognized.
The blue jay feeds mainly on seeds and nuts, such as acorns, which it may hide to eat later; soft fruits; arthropods; and occasionally small vertebrates. It typically gleans food from trees, shrubs, and the ground, and sometimes hawks insects from the air. Blue jays can be very aggressive to other birds; they sometimes raid nests and have even been found to have decapitated other birds.
It builds an open cup nest in the branches of a tree; both sexes participate. The clutch may be two to seven eggs, which are blueish or light brown with darker brown spots. Young are altricial, and are brooded by the female for 8–12 days after hatching. They may stay with their parents for one to two months.
The name jay derives from the bird's noisy, garrulous nature and has been applied to other birds of the same family, which are also mostly gregarious. Jays are also called jaybirds.
La blua garolo[mankas fonto] (Cyanocitta cristata) estas paserina birdo, membro de la familio de Korvedoj indiĝenaj de Nordameriko. Ĝi apartenas al la grupo de "bluaj" aŭ amerikaj garoloj, kiuj estas, inter korvedoj, ne tre proksima al la aliaj garoloj. Ĝi estas adaptebla, agresema kaj ĉiomanĝanta, kaj koloniigis novajn habitatojn dum multaj jardekoj.
La Blua garolo estas 22–30 cm longa el beko al vosto kaj pezas 70–100 g, kun enverguro de 34–43 cm.[1] Estas tre markita kresto kape, sed ne tiom markita kiom ĉe la pigogaroloj, tio estas krono de plumoj, kiuj povas esti levataj aŭ mallevataj laŭ la birda bonfarto. Kiam estas ekscitita aŭ agreseca, la kresto povas leviĝi. Kiam la birdo estas timigita, la kresto hirtiĝas foren, kiel broŝo. Kiam la birdo manĝas inter aliaj garoloj aŭ ripozas, la kresto estas ebena sur la kapo.[2]
Ties plumaro estas lavendoblua al mezblua en kresto, pli grizblua en dorso kaj pli markita blua en flugiloj kaj vosto, dum la vizaĝo estas blanka kaj ĉirkaŭita de ringo simila kiel tiu de la pigogaroloj, kio separas ĝin el la nuko kaj el la brusto; en la vizaĝo kontrastas la nigraj beko, okuloj kaj brido. La brusto estas helgrizeca kaj la ventro estas pli blankeca kaj tre blanka en subvosto. La unuarangaj flugilplumoj kaj vosto estas tre striitaj de nigro, ĉielbluo kaj blanko, kio videblas ripoze kiel ĝenerala helblua koloro el meza dorso al la flugilpinto kun nigra horizontala strietaro, pli da nigro en dorsopinto kaj tre kontrastaj blankaj kvadatretoj en horizontalaj flankaj strioj en meza dorso, alia vertikala en dorsopinto kaj respektivaj anguloj en la eksteraj vostoplumoj. La gamboj estas nigraj. Maskloj kaj inoj estas preskaŭ identaj; sed maskloj estas iomete pli grandaj.[3]
Kiel ĉe aliaj blunuancaj garoloj, la koloro de la Blua garolo ne devenas el pigmentoj, sed ĝi estas rezulto de hela refraktado pro la interna strukturo de la plumoj; se bluan plumon oni premas, la bluo malaperas ĉar la strukturo malaperis. Tio estas konata kiel struktura koloro.
Bluaj garoloj havas fortajn nigrajn bekojn uzatajn por rompi nuksojn kaj glanojn kaj por manĝi maizon, grenon kaj semojn, kvankam ili manĝas ankaŭ insektojn kiel skaraboj, saltuloj kaj raŭpoj.
Bluaj garoloj povas fari grandan varion de sonoj, kaj individuoj povas varii percepteble en sia alvoka stilo. Kiel aliaj korvedoj, ili povas lerni imiti homan paroladon. Bluaj garoloj povas ankaŭ kopii la krion de lokajn akcipitrojn tiom bonkvalite ke foje malfacilas scii pri kio temas.[4] Ties voĉo estas tipa de plej parto de garoloj en tio ke estas varia, sed la plej komune konata sono estas la alarmo, kiu estas laŭta, kvazaŭ krio de mevo. Estas ankaŭ altatona alvoko kiu rapidiĝas dum la birdo agitiĝas. Bluaj garoloj uzas tiujn alvokojn kune por ĉikani eventualajn predantojn kiel akcipitroj kaj forigi ilin el la garolaj nestoj.
Bluaj garolo havas ankaŭ pli silentecan kaj preskaŭ subliminajn alvokojn kiujn ili uzas inter ili en la proksimeco. Unu el la plej distingaj alvokoj de tiu tipo ofte estas menciata kiel "rusta pumpilo" pro ties similo al malnova akvopumpilo. La Blua garolo (kaj aliaj korvedoj) estas distingaj el ĉiuj aliaj kantobirdoj por uzi sian alvokon kiel kanto.
La Blua garolo loĝas el suda Kanado tra orienta kaj centra Usono suden al Florido kaj nordorienta Teksaso. La okcidenta bordo de la teritorio haltas kie komencas la arida pinarbaro kaj la makisa habitato de la tre prokisma rilata Stelera garolo (C. stelleri). La teritorio de la Blua garolo ĵus etendiĝis nordokcidenten tiom ke nuntempe estas rara sed regule vidata vintra vizitanto laŭlonge de norda Usono kaj suda marbordo de Pacifiko en Kanado,[5] kaj kelkaj perditaj birdoj povas ĉeesti eĉ en Kalifornio nuntempe. Ĉar la teritorioj de la du specioj nune koincidas, C. cristata povas foje hibridiĝi kun la Stelera garolo.[6]
La plej norda subspecio C. c. bromia estas migranta, laŭ neceso. Ili povas retiriĝi kelkajn centojn da kilometroj suden el la plej nordaj partoj de sia teritorio, sed eĉ nordaj birdoj ne nepre moviĝas suden, ĉefe en mildaj jaroj kun multe da vintra manĝo. Ili migras dumtage en izolitaj aroj el 5 al 250 birdoj.
Ĝenerale oni agnoskas kvar subspeciojn, kvankam la varioj en tiu specio estas tre subtilaj kaj ĉefe klinaj. Oni ne povas marki certajn limojn inter la internaj subspecioj. La teritorioj de la marbordaj rasoj estas pli bone limigitaj.[7]
Brila Cyanocitta cristata cristata, Kantono Johnston, Norda Karolino.
A C. c. cyanotephra ripoze en DeSoto National Wildlife Refuge, Iovao.
En Kantono Collier, Florido loĝas la malgranda C. c. semplei.
La Blua garolo okupas varion de habitatoj ene de sia granda teritorio, el la arbaroj de pinoj de Florido al la arbaroj de piceo kaj abio de norda Ontario. Ili estas malpli abunda en pli densaj arbaroj, preferas miksitajn arbarojn de kverkoj kaj fagoj.[2] Ili lerte adaptiĝis al homa aktiveco kaj loĝas en parkoj kaj loĝaj setlejoj, kaj povas adaptiĝi eĉ al ĝenerala senarbarigo relative facile se la homa agado kreas aliajn rimedojn por la garoloj.[8]
La Blua garolo estas meze malrapida fluganto[9] kaj facila predo por akcipitroj kaj gufoj, kiam ili flugas en malfermaj teroj. Ili flugas kun levitaj korpo kaj vosto, per malrapida fugilfrapado. Ili estas ĝenerale energiaj al aliaj birdoj, kaj ili povas forpeli birdojn el birdomanĝejoj aŭ aliaj manĝeĵoj. Ili povas forpeli predantojn, kiel akcipitroj kaj gufoj kiuj eventuale manĝas garolojn, kaj krias se ili vidas predanton en sia teritorio. Oni konas ankaŭ ties alarman alvokon antaŭ proksimeco de akcipitroj aŭ aliaj danĝeroj, kaj tiele pli malgrandaj birdoj ofte rekonas tiun alvokon kaj kaŝiĝas akurate. Ili povas esti ankaŭ agresemaj al homoj kiuj venas proksime de sia nesto, kaj se gufo ripozas proksime de la nesto dumtage la Blua garolo ĉikanas ĝin ĝis kiam ĝi iras al nova ripozejo.[10]
Bluaj garoloj, kiel aliaj korvedoj, estas tre scivolemaj kaj inteligentaj birdoj. Junaj individuoj ludeme prenegas brilkolorajn aŭ reflektajn objektojn, kiel botelŝtopiloj aŭ pecoj de aluminipapero, kaj kunportas ilin ĝis kiam ili perdas intereson.[10] Bluaj garoloj estis observataj en kaptiveco uzantaj striojn de ĵurnaloj kiel iloj por akiri manĝaĵojn.[11]
Ili manĝas kaj surgrunde kaj en arboj kaj la manĝo inkludas ĉiujn konatajn tipojn de plantoj kaj animaloj, kiel glanoj kaj fagofruktoj, semoj de trudherbo, greno, fruktoj kaj beroj, ternuksoj, pano, viando, etaj senvertebruloj de multaj tipoj, restaĵoj en urbaj parkoj, birdomanĝaĵoj kaj pli rare ovoj kaj birdidoj[12][13]. Bluaj garoloj foje kaŝas manĝaĵojn, sed tiu kutimo ege diferencas laŭ individuoj.
La reprodukta sezono komencas en meza marto, vigliĝas en meza aprilo al majo kaj etendiĝas al julio. Oni uzas taŭgan arbon aŭ grandan arbuston por nestumado, kvankam oni preferas ĉiamverdajn. La nesto estas prefere konstruita je 3 al 10 m alte. Ĝi estas tasforma kaj komponita el bastonetoj, etaj radikoj, arboŝeleroj, musko, alia planta materialo, tolaĵoj, papero kaj plumoj, kun eventuala koto aldone.
Bluaj garoloj ne estas tre postulemaj pri nestolokoj. Se ne estas pli bona loko disponebla - ekz. en tre senarbarigata areo - ili eĉ uzas lokojn kiel grandaj leterkestoj tipaj de rura Usono.[8] Ili ankaŭ alproprigas nestojn de aliaj mezgrandaj kantobirdoj se ili situas en akurataj lokoj; Bluaj garoloj uzas kutime nestojn de Migra turdo ekzemple.
Bluaj garoloj tipe formas monogaman paron dumvive. Ambaŭ seksoj konstruas la neston kaj zorgas la idojn, kvankam nur la ino kovas. La masklo manĝigas la inon dum ŝi kovas la ovojn. Tiuj esta kutime 4 aŭ 5 kaj estas kovataj dum ĉirkaŭ 16-18 tagoj. Elnestiĝo okazas 17-21 tagojn post eloviĝo.[10]
Post elnestiĝo la familio veturas kaj manĝas kune ĝis frua aŭtuno, kiam la junuloj disiĝas por eviti konkurencon por manxgo dum vintre.
La blua garolo[mankas fonto] (Cyanocitta cristata) estas paserina birdo, membro de la familio de Korvedoj indiĝenaj de Nordameriko. Ĝi apartenas al la grupo de "bluaj" aŭ amerikaj garoloj, kiuj estas, inter korvedoj, ne tre proksima al la aliaj garoloj. Ĝi estas adaptebla, agresema kaj ĉiomanĝanta, kaj koloniigis novajn habitatojn dum multaj jardekoj.
La chara azul (Cyanocitta cristata),[2] también denominada arrendajo azul o urraca azul, es una especie de ave paseriforme de la familia Corvidae propia de América del Norte.
Su plumaje es predominantemente azul de medio cuerpo para arriba, de la cabeza a la cola. Tiene una cresta pronunciada. El color cambia a negro, celeste y con listas blancas en las rémiges y las caudales. Por debajo es blanco, con un collar negro alrededor del cuello y los lados de la cabeza, y con la cara blanca.
Como en otras aves azuladas, la coloración del arrendajo azul no deriva de pigmentos, sino que es el resultado de la refracción de la luz debida a la estructura interna de las plumas; si se aplasta una de las plumas la coloración azul desaparece, pues la estructura ha sido destruida. Esto se llama coloración estructural.
El canto se parece al de otros córvidos en que es muy variado, pero el sonido más común es la voz de alarma, que es un grito ruidoso, casi como el de una gaviota. También emiten un agudo yaie-yaie, cuya frecuencia aumenta a medida que el ave se excita.
Ocupa gran parte del este de Norteamérica, desde Terranova hasta Florida, llegando por el suroeste de su distribución hasta Texas, y a Colorado por el noroeste. Al oeste de las Rocosas es reemplazado por el arrendajo de Steller. También hay ejemplares en el estado mexicano de Tamaulipas que se destribuyen en la Reserva de la Biósfera El Cielo.
Aunque la chara azul por lo general permanece todo el año en su área de distribución, algunas poblaciones norteñas migran a la parte sur de la distribución en invierno (migran de día).
Se encuentra sobre todo en bosques mixtos (que incluyen el haya americana y varias especies de roble), pero también es visible en parques y jardines de algunas ciudades.
Busca su comida tanto en el suelo como en los árboles, y consume prácticamente todo tipo de alimentos vegetales y animales, tales como bellotas, hayucos, semillas de herbáceas, granos, frutos, bayas, cacahuetes, pan, carne, huevos y polluelos de otras aves, muchos tipos de invertebrados, basura de los parques y alimento para pájaros.
Su comportamiento agresivo en los cebaderos de pájaros, así como su mala reputación como destructor de nidos y huevos de otros pájaros han hecho que a menudo el arrendajo azul no sea bienvenido en muchos comederos por quienes los instalan. Su mala fama ha pasado a la literatura, como en la novela de Harper Lee Matar un ruiseñor.
Cualquier árbol o arbusto grande disponible les sirve para anidar. Hembra y macho colaboran en construir el nido y alimentar a la nidada, aunque solo la hembra empolla. La puesta suele ser de cuatro o cinco huevos y es incubada durante dieciséis a dieciocho días. Generalmente los polluelos vuelan entre los diecisiete y veintiún días.
Típicamente forman parejas monógamas de por vida.
La chara azul (Cyanocitta cristata), también denominada arrendajo azul o urraca azul, es una especie de ave paseriforme de la familia Corvidae propia de América del Norte.
See artikkel räägib liigist; perekonna kohta vaata artiklit Sininäär (perekond) Sininäär (Cyanocitta cristata) on vareslaste sugukonda sininääri perekonda kuuluv lind.
Sininäär on nokast sabaotsani 22–30 cm pikk ja kaalub 70–100 g. Tiibade siruulatus on 34–43 cm.
Peas on sulgedest tutt, mida lind saab oma soovi kohaselt tõsta ja langetada. Kui lind on agressiivne või ärevil, on tutt täielikult tõstetud. Ehmunud sininääri tutt on pintslisarnane, aga kui lind puhkab või toitub parves, on tutt pealigi langetatud.
Sininääri sulestik on sinine kuni kahvatulilla ja sellest ongi ta nime saanud. Saba- ja kõhualune ning nägu on seevastu valged. Kaelal on must krae, mis tõuseb näo külgi mööda silmade kõrgusele. Nokk, jalad ja silmad on kõik mustad. Isas- ja emaslindude sulestik on ühesugune.
Nagu enamikul sinistest lindudest, ei tule ka sininääril sinine värvus pigmendist, vaid valguse interferentsist sulgede struktuuris. Kui näiteks sinine sulg purustada, siis sinine värvus kaob, sest seda värvust tekitav struktuur hävib.
Sininäär on levinud Põhja-Ameerikas. Tema levila läänepiir läbib Texase, New Mexico, Colorado, Wyomingi ja Montana, levila põhjapiir kulgeb Kanadas. Levila hõlmab kogu Florida poolsaare ja Newfoundlandi.
Sininääri levilast lääne poole kuni Vaikse ookeanini elab tema lähim sugulane Stelleri sininäär Cyanocitta stelleri. Seal, kus nende kahe liigi levila kokku saab, on täheldatud nende hübriide.
Sininäär on USA-s paigalind, Kanadas (välja arvatud Ontario lõunaosa ja Newfoundland) rändlind. Nad rändavad 5–250 isendist koosnevate parvedena, alati päeval.
Sininääri ränne on paljuski segane. Kõigepealt on teada, et kusagil levilas ei toimu ränne täies ulatuses: alati jääb üksikuid isendeid talvituma. On teada, et nooremad linnud on altimad rändama kui vanemad, aga rändavad vanalinnudki. Järjekindlust pole üksikisenditegi seas: on juhtunud, et üks isend ühel talvel rändab, teisel talvitub ja kolmandal rändab jälle. Niisuguse käitumise põhjuseid ei osata korralikult selgitada ega sininääride järgmise sügise rännet ennustada.
Sininääril eristatakse nelja alamliiki.
Sininäär on julge, kärarikas ja agressiivne lind. Harilikult ei lenda ta kuigi kiiresti: 32–40 km/h. Lennu ajal on selg ja saba ühel tasapinnal ning ta liigub aeglaste tiivalöökidega. Aeglase lennukiiruse tõttu on ta röövlindudele kerge saak, eriti kui ta lendab üle avatud maastiku. Kõik röövlinnud, kelle levila kattub sininääri omaga, võivad talle jahti pidada, eriti need, kes on spetsialiseerunud lindude püüdmisele õhust.
Mitmesugused röövloomad võivad süüa sininääri mune ja poegi: oravad, maod, kassid, varesed, opossumid ja isegi teised sininäärid, kõige tõenäolisemalt ka kõik need röövlinnud, kes kütivad täiskasvanuid.
Sininäärist on teistele värvulistele kasu, sest ta moodustab salku ning tungib nendega kallale üksikutele kullidele ja kakkudele, samuti karjub, kui näeb röövlindu oma maa-alal. Sininääri hoiatushüüdu kuulevad teisedki väikesed linnud ja poevad selle mõjul peitu. Kui sininääride lähedusse asub öökull, siis võivad sininäärid teda karjaga kimbutada senikaua, kuni öökull otsib endale uue elupaiga. Sininäär võib olla agressiivne inimesegi suhtes, kes tema pesale liiga lähedale tuleb.
On täheldatud, et sininäär imiteerib mõne röövlinnu kutsehüüdu. Põhiliselt kutsub ta viusid Buteo jamaicensis ja Buteo lineatus. Arvatakse, et nii soovib sininäär lihtsalt kontrollida, kas vaenlane on läheduses, aga võib-olla ehmatada ka teisi linde toidu juurest eemale.
Juhtub, et sininäär rüüstab teiste lindude pesi, varastades nii mune, poegi kui pesamaterjali. Siiski ei ole see nii sage kui arvatakse. Ainult 1% sininääri toidust moodustavad teised linnud. Sellest hoolimata juhtub, et väikesed värvulised ründavad salgaga üksikut sininääri samamoodi nagu sininääride salk röövlindu.
Sininäär on territoriaalne lind ja kaitseb oma maa-ala. On täheldatud, et sininäär ajab teisi linde oma maa-alale paigaldatud lindude söögimaja juurest eemale ega luba neil sealt süüa.
Nagu teisedki vareslased, on sininääridki väga uudishimulikud ja neid peetakse intelligentseteks lindudeks. Vabas looduses ei ole kohatud neid tööriistu kasutamas, küll aga on nad seda teinud vangistuses, samuti on nähtud puuris peetavaid noorlinde proovimas puuri ust avada.
Sininäär (Cyanocitta cristata) on vareslaste sugukonda sininääri perekonda kuuluv lind.
Eskinoso urdina (Cyanocitta cristata) Cyanocitta generoko animalia da. Hegaztien barruko Corvidae familian sailkatua dago.
Eskinoso urdina (Cyanocitta cristata) Cyanocitta generoko animalia da. Hegaztien barruko Corvidae familian sailkatua dago.
Sinitöyhtönärhi (Cyanocitta cristata) on pohjoisamerikkalainen töyhtönärhien sukuun kuuluva varpuslintu.
Linnun pituus on 22–30 cm ja paino 70–100 grammaa. Höyhenpuku on kaksivärinen: linnun alapuoli ja naama ovat valkoiset tai vaaleanharmaat ja selkäpuoli, päälaki, siivet ja pyrstö siniset. Sukupuolet ovat samanvärisiä, mutta koiras on kooltaan hieman suurempi.
Vanhin rengastettu sinitöyhtönärhi eli 17,5-vuotiaaksi. Vankeudessa pidetty naaras eli 26 vuotta ja kolme kuukautta vanhaksi.
Sinitöyhtönärhi elää Pohjois-Amerikassa Yhdysvaltojen itä- ja keskiosissa aina Floridassa ja Texasin itäosissa asti sekä Kanadan etelä- ja itäosissa. Lajin esiintymisalueen laajuus on 6,7 miljoonaa neliökilometriä ja maailmanpopulaation koko on noin 22 miljoonaa yksilöä.
Sinitöyhtönärhet asuvat valoisissa sekametsissä, puistoissa ja istutusmetsiköissä, myös ihmisasutuksen liepeillä.
Sinitöyhtönärhet muodostavat yleensä elinikäisen parisuhteen. Ne lisääntyvät pohjoisilla alueilla kerran kesässä, etelässä kahdesti, ja rakentavat risuista löyhän pesärakennelman puuhun tai pensaaseen. Naaras munii 3–6 munaa, keskimäärin 4,5. Pääosin naaras hautoo noin 17 päivää, ja koiras käy ruokkimassa sitä haudonnan aikana. Poikasia hoitavat molemmat vanhemmat. Poikaset jättävät pesän 17–21 päivän ikäisinä ja itsenäistyvät pari kuukautta myöhemmin. Sinitöyhtönärhi saavuttaa sukukypsyyden yksivuotiaana.
Sinitöyhtönärhi on kaikkiruokainen lintu, jolle kelpaavat siemenet, hedelmät, marjat, hyönteiset ja muut selkärangattomat, sammakot, linnunpoikaset ja munat sekä jätteet. Se kaivaa syksyisin maahan ruokavarastoja talven varalle.
Sinitöyhtönärhi (Cyanocitta cristata) on pohjoisamerikkalainen töyhtönärhien sukuun kuuluva varpuslintu.
Cyanocitta cristata
Le Geai bleu (Cyanocitta cristata) est une espèce de passereaux de la famille des corvidés.
Le Geai bleu présente les caractéristiques suivantes :
Geai bleu à Welland.
Un geai bleu à Prospect Park, New York. Avril 2021.
Geai bleu au cimetière de Green-Wood, New York. Juillet 2021.
Cette espèce ne présente pas de dimorphisme sexuel. C'est un oiseau très bruyant nichant régulièrement au Québec. Sa huppe courte (milieu à l'arrière du vertex) et les parties supérieures de son plumage sont bleues alors que son ventre est gris blanchâtre. Il porte un collier noir, ses ailes et sa queue sont parsemées de points blancs. Le mâle et la femelle ont la même apparence, mais le mâle est un peu plus grand que la femelle.
Le juvénile est plus terne avec le dessus plus gris et les couvertures alaires presque sans barres. Celles des secondaires et des rectrices sont moins régulières et présentent moins de blanc à leurs extrémités.
Son aire de répartition s'étend à l'est de l'Amérique du Nord, du sud du Canada et au golfe du Mexique.
Ses milieux de vie sont les forêts de feuillus et les bois épars.
Il fait preuve d'un comportement singulier en prenant des bains de fourmis. Il se jette par surprise toutes ailes déployées dans une fourmilière obligeant ainsi les insectes affolés à sécréter de l'acide formique pour se défendre. Ce comportement singulier, appelé « formicage », peut s'expliquer par le fait que l'oiseau utilise l'acide formique pour se débarrasser de ses tiques et autres parasites du plumage constituant ainsi pour les fourmis un stock de nourriture en récompense.[réf. nécessaire] Il mange aussi du pain.
Cet oiseau est représenté par quatre sous-espèces :
Le geai bleu est l'emblème aviaire de la province de l'Île-du-Prince-Édouard. Il est également l'emblème de l'équipe de baseball de Toronto, les Toronto Blue Jays, qui évolue en MLB.
Mordecai, personnage de la série d'animation américaine Regular Show, est un geai bleu.
Cyanocitta cristata
Le Geai bleu (Cyanocitta cristata) est une espèce de passereaux de la famille des corvidés.
La ghiandaia azzurra americana o semplicemente ghiandaia azzurra (Cyanocitta cristata (Linnaeus, 1758)) è un uccello passeriforme della famiglia dei Corvidi[2].
Misura 25-30 cm di lunghezza, per 70-100 g di peso e 24-43 cm di apertura alare[3].
Si tratta di uccelli dall'aspetto robusto ma slanciato, muniti di testa arrotondata con forte becco conico e allungato, ali digitate, coda piuttosto lunga (circa un terzo della lunghezza totale) e dall'estremità arrotondata e forti zampe. Caratteristica di questi uccelli è la presenza di penne erettili nell'area del vertice, rizzate a formare una piccola cresta appuntita quando l'animale è eccitato o spaventato e praticamente invisibili a riposo.
Il piumaggio è inconfondibile e uguale nei due sessi: l'area attorno alle narici, il sopracciglio, le guance ed il mento, così come il sottocoda, sono di colore bianco sporco, talvolta con lievissime sfumature azzurrine. La base superiore del becco e l'area fra quest'ultimo e l'occhio sono invece di colore blu-nerastro, che si prolunga in una sottilissima banda fino all'area auricolare, dove scende fino alla gola, a formare un collare che cinge l'area biancastra facciale. Fronte, vertice, nuca, dorso e ali sono di colore azzurro-blu, con le copritrici primarie più vivide e metallizzate, munite di barre scure, e le remiganti dello stesso colore, ma munite inoltre di punta di colore bianco: la coda è anch'essa di questo colore, con orlo bianco piuttosto sottile superiormente, mentre la sua superficie inferiore è interamente biancastra, con ampia banda trasversale bruno-nerastra in posizione mediana. Il petto e i fianchi sono di colore bruno-grigiastro, che sfuma nel bianco sul ventre.
Il becco e le zampe sono di colore nero-bluastro, talvolta con riflessi violacei, mentre gli occhi sono di colore bruno scuro.
La ghiandaia azzurra è un uccello dalle abitudini di vita essenzialmente diurne, che vive da solo o in coppie e si dimostra molto territoriale, cacciando aggressivamente eventuali intrusi conspecifici dal proprio territorio, soprattutto dalle vicinanze del nido (durante il periodo riproduttivo) e delle fonti di cibo: anche i predatori (soprattutto i gufi) vengono importunati qualora avvistati durante il giorno, venendo infastiditi fino a quando non si allontanano.
Intelligenti e curiose come tutti i corvidi, le ghiandaie azzurre mostrano interesse negli oggetti luccicanti, che rubano in maniera simile alle gazze, tenendoli nel becco fino a quando non se ne sono stancate: questi uccelli mostrano inoltre la propensione (verificata tuttavia finora solo in condizioni di cattività) a servirsi di oggetti come strumenti per ottenere il cibo o tentare di aprire la propria gabbia[4].
Si tratta di uccelli piuttosto rumorosi, che si tengono in costante contatto sonoro fra loro, esibendo un repertorio piuttosto vasto di richiami, che vanno dagli aspri gracchi d'allarme (vagamente simili ai versi dei gabbiani) emessi all'apparizione di eventuali predatori, ai richiami bassi e chioccolanti rivolti al partner, passando per il verso simile a quelli delle cince emesso dagli animali che si stanno agitando: la ghiandaia azzurra è inoltre un buon imitatore dei suoni uditi nel proprio territorio (anche della voce umana), in particolare le imitazioni dei versi dei rapaci (soprattutto poiana della Giamaica e poiana spallerosse) potrebbero servire a questi uccelli sia a spaventare eventuali competitori per le fonti di cibo, che a testare l'effettiva presenza di questi predatori nel loro territorio, in quanto le ghiandaie azzurre, volatori moderatamente veloci (32-40 km/h), sono molto vulnerabili agli attacchi dei rapaci in campo aperto.
La maggior parte della dieta della ghiandaia azzurra è costituita da materiale di origine vegetale, come semi, granaglie, frutta matura, bacche, frutti di bosco e soprattutto frutta a guscio, che viene spaccato col forte becco: questi uccelli si nutrono inoltre di uova, insetti, piccoli invertebrati ed occasionalmente anche di piccoli vertebrati, come topolini, nidiacei, lucertole e in un singolo caso un pipistrello (Lasiurus borealis), anche se la componente animale della loro dieta è sempre minoritaria e composta in massima parte da invertebrati. Si tratta ad ogni modo di uccelli piuttosto adattabili e opportunistici, che possono nutrirsi anche di linfa (che in alcuni periodi dell'anno ammonta a quasi la metà del totale del cibo ingerito) o di rimasugli di cibo rinvenuti nella spazzatura: le ghiandaie azzurre sono inoltre assidue frequentatrici delle mangiatoie tradizionalmente posizionate nei cortili delle case americane, dove (a dispetto dell'alta aggressività territoriale e della sfrontatezza ostentata in molte occasioni) si mostrano subordinate nell'ordine di accesso al cibo a tutte le specie di dimensioni paragonabili, nonché ad alcune specie di piccoli uccelli particolarmente aggressive ed allo scoiattolo grigio.
Il cibo viene rinvenuto indifferentemente al suolo o fra alberi e cespugli, con le prede alate talvolta catturate al volo: il pasto si svolge attraverso il metodo della spigolatura.
Similmente ad altri corvidi, le ghiandaie azzurre sono solite immagazzinare il surplus di cibo in depositi scaglionati in giro per il proprio territorio durante i periodi di abbondanza di cibo, servendosene poi durante il periodo freddo.
Si tratta di uccelli rigidamente monogami, che si riproducono dalla metà di marzo ai primi di luglio.
Il nido viene costruito da ambedue i partner a 3-10 m d'altezza su un albero (di preferenza una conifera), o in una struttura analoga, come un palo della luce o una cassetta delle lettere: esso ha forma di una coppa ed è composto da rametti, fibre vegetali (radichette, strisce di corteccia, muschio e licheni) e non di rado in ambienti antropizzati anche di materiale antropogeno (pezzi di stoffa e strisce di carta), il tutto stabilizzato con aggiunta di piumino e terra masticata e impastata con la saliva.
In mancanza di siti adeguati per la nidificazione, le ghiandaie azzurre possono sfrattare nidi di altre specie dai precedenti inquilini ed occuparli con la forza, eventualmente rimaneggiandoli: a fare le spese di questo comportamento sono soprattutto i tordi pettirossi.
La covata va da due a sette uova (generalmente 4-5), che sono bluastre o marrone chiaro, con presenza di una rada punteggiatura più scura: esse vengono incubate dalla sola femmina (imbeccata nel frattempo dal maschio, che rimane sempre nei pressi del nido a difesa da eventuali intrusi) per 16-18 giorni, al termine dei quali schiudono pulli ciechi ed implumi.
I piccoli vengono imbeccati dalla sola femmina (a sua volta imbeccata dal maschio) per i primi 8-12 giorni di vita: trascorso questo periodo, essi cominciano a fare capolino dal nido ed anche il maschio comincia ad imbeccarli. L'involo avviene a circa tre settimane dalla schiusa, tuttavia i giovani continuano a rimanere presso il nido almeno per un paio di mesi, seguendo i genitori nei loro spostamenti e chiedendo loro l'imbeccata (sebbene sempre più sporadicamente) e separandosene definitivamente solo alle porte dell'autunno, disperdendosi per evitare competizione per il cibo.
La maturità sessuale viene raggiunta attorno all'anno di vita, sebbene sia raro che questi uccelli (soprattutto i maschi) riescano a trovare un partner prima dei 2-3 anni di vita: la loro speranza di vita si aggira attorno ai 7 anni in natura (con singoli esemplari che hanno superato i 15-17 anni), estendendosi fino a 26 anni in cattività[5].
La ghiandaia azzurra è diffusa in Nordamerica centro-orientale, occupando un areale che va dall'isola di Terranova alla Florida attraverso Nuova Scozia, costa sud-orientale del Québec (isola d'Anticosti inclusa) ed East Coast, spingendosi ad ovest attraverso la regione dei Grandi Laghi e lungo il confine tra il Canada e gli Stati Uniti d'America fino alle Montagne Rocciose (dove viene sostituita dall'affine ghiandaia di Steller) e al Texas sud-orientale e nord-occidentale. Negli ultimi anni, complice il rimboschimento delle Grandi Pianure, l'areale della specie sembra essere in espansione in direttrice nord-ovest, con osservazioni rare ma sempre più frequenti di esemplari nell'area pacifica al confine fra USA e Canada[6].
La ghiandaia azzurra è un uccello tendenzialmente stanziale nella maggior parte del proprio areale: nelle popolazioni più settentrionali (in particolare quelle della sottospecie bromia) possono essere presenti abitudini migratorie, con una parte degli uccelli che si sposta verso sud con l'approssimarsi della stagione fredda.
Sebbene l'habitat d'elezione di questi uccelli siano le aree boschive e di foresta, sia mista che di conifere o latifoglie, con presenza di radure o aree aperte nei dintorni, la ghiandaia azzurra si dimostra piuttosto adattabile alla presenza dell'uomo, e (pur evitando le aree più secche, preferite invece dalla già citata e congenere ghiandaia di Steller) si spinge nelle aree alberate dei centri urbani, come giardini, parchi e viali.
Se ne riconoscono quattro sottospecie[2]:
Esemplare della sottospecie bromia si alimenta nell'Ontario.
Esemplare della sottospecie nominale nella contea di Johnston.
Esemplare della sottospecie semplei nella contea di Collier.
Esemplare della sottospecie cyanotephra nell'Iowa.
Le quattro sottospecie si differenziano soprattutto in base a criteri morfologici che riguardano la vividezza della colorazione e la diminuzione della taglia e seguono un andamento clinale in direttrice N-S, tanto che alcuni autori dubiterebbero dell'effettiva validità del taxon semplei e propenderebbero per un suo accorpamento alla sottospecie nominale[3].
La ghiandaia azzurra americana o semplicemente ghiandaia azzurra (Cyanocitta cristata (Linnaeus, 1758)) è un uccello passeriforme della famiglia dei Corvidi.
Zilais sīlis (Cyanocitta cristata) ir vidēja lieluma vārnu dzimtas (Corvidae) putns. Izdala 4 pasugas.[1]
Zilais sīlis ir tipisks Ziemeļamerikas putns. Tā izplatības areāls ir ļoti liels, tas sākas Kanādas dienvidos, aizņem lielas teritorijas ASV vidienē un austrumu krastā, un beidzas Floridas piekrastē un Teksasas ziemeļos. Rietumu robeža zilā sīļa izplatībai robežojas ar sausajiem priežu mežiem. Šie meži ir zilā sīļa tuvākā radinieka Stellera sīļa (Cyanocitta stelleri) izplatības areāla austrumu robeža. Pēdējos gados ziemeļu reģionos zilais sīlis ir ekspandējies uz rietumiem līdz Klusā okeāna krastam.[2] Tā kā mūsdienās abu sugu izplatības areāli ziemeļos pārsedzas, iespējams tās savā starpā reizēm hibridizējas.[3]
Zilā sīļa ķermeņa garums, asti ieskaitot, ir 22—30 cm, spārnu plētums 34—43 cm, svars 70—100 g.[2] Abi dzimumi ir līdzīgi viens otram, tikai tēviņi ir nedaudz lielāki, nekā mātītes.[4]
Uz galvas zilajam sīlim ir izteiksmīgs cekuls. Atpūtas un barošanās brīžos cekuls pieglaužas pie galvas, bet, ja sīlis ir dusmīgs un agresīvs, cekuls ir sasliets stāvus gaisā. Bailes izpaužas izspūrušā cekulā, kas kļūst līdzīgs otai.[5] Tā apspalvojums ir gaiši zilā krāsā, bet uz sejas, krūtīm un vēdera balts. Seju un kakla rīkles daļu norobežo melna lenta, kas savienojas uz pakauša. Spārniem veidojas ornaments no zilām, baltām un melnām spalvām, bet astes spalvas ir svītrainas — zilās lidspalvas ir greznotas ar šaurām, melnām šķērssvītriņām. Knābis, kājas un acis ir melnas. Knābis ir ļoti spēcīgs, jo zilais sīlis to lieto kā āmurīti riekstu un zīļu sasišanai.
Zilais sīlis ir nometnieks, un visu gadu pavada vienā un tajā pašā vietā. Izņēmums ir ziemeļos dzīvojošā pasuga C. c. bromia, kas ziemas periodā migrē uz dienvidiem. Tie nolido vairākus 100 km līdz ziemošanas vietām. Zilie sīļi migrē tikai dienas laikā, veidojot baru no 5 līdz 250 putniem. Tomēr siltās ziemās, kad barības ir daudz, arī ziemeļos dzīvojošie sīļi paliek ligzdošanas vietās un nemigrē.
Zilā sīļa izplatības areālā ir ļoti liela biomu daudzveidība. Dienvidos Floridā tie ir mitrie priežu meži, bet ziemeļos Kanādas egļu meži. Zilajam sīlim vismīļākie ir ozolu un dižskābaržu meži, kā arī jauktu koku meži.[5] Tas ir labi piemērojies dzīvei blakus cilvēkiem, tam patīk apmesties pilsētu parkos un dārzos. Zilais sīlis viegli nomaina izcirstos mežus pret cilvēku stādītiem apstādījumiem.[6]
Zilais sīlis ir diezgan lēns lidotājs, tā lidošanas ātrums ir 32—40 km/h, tādējādi atklātās vietās vientuļš zilais sīlis kļūst par diezgan vieglu mērķi plēsīgajiem putniem, kā vanagiem un pūcēm. Pret citiem putniem tas var kļūt agresīvs barošanās vietās, cenšoties tos padzīt no putnu barotavām vai citām barošanās vietām. Lai gan tas nenotiek tik bieži, cik bieži zilo sīli par to vaino. Citiem maziem pautniem ir izdevīgi atrasties zilā sīļa tuvumā, jo zilais sīlis skaļi kliedz, ja pamana plēsīgos putnus, kā arī tas cenšas tos padzīt no savas teritorijas. Ja pūce ir apmetusies dienas laikā atpūsties zilā sīļa ligzdas tuvumā, tas uzbrūk tai tik ilgi līdz tā atrod citu atpūtas vietu. Reizēm zilais sīlis medī mazos putniņus barības iegūšanai.[7]
Zilie sīļi ir vieni no inteliģentākajiem putniem. Tas ir ļoti ziņkārīgs un apķērīgs. Diezgan ierasta un bieži novērota situācija, kad sīlis pamana kādu cilvēku ar kaut ko ēdamu rokās, tas vēro cilvēku un līdzko pārtika netiek pieskatīta, tas to cenšas nozagt. Zilais sīlis diezgan bieži izseko cilvēkus, strādājot dārzā, sēklu sēšanas laikā. Līdzko cilvēks pamet dobi, tas izkašā sēklas un apēd tās. Jaunajiem putniem patīk rotaļāties ar spīdīgiem un krāsainiem priekšmetiem.[7] Nebrīvē sīļi iemācās izmantot palīginstrumentus, lai iegūtu barību.[8]
Zilais sīlis ir visēdājs, tas barojas ar riekstiem, zīlēm, kukurūzu, dažādiem labības graudiem, sēklām, ogām, augļiem, kukaiņiem, kā vaboles, sienāži un tauriņi. Retu reizi tas izēd citiem putniem olas un putnēnus.[2] Zilais sīlis barību meklē gan uz zemes, gan kokos.
Riests zilajiem sīļiem sākas martā un beidzas maijā, reizēm tas ievelkas līdz jūlijam. Ligzdai tiek noskatīts kāds liels koks vai krūms, priekšroka tiek dota mūžzaļajiem kokiem un krūmiem. Ligzda tiek uzbūvēta 3—10 metru augstumā no zemes. Tai ir bļodas forma, zilais sīlis to būvē no smalkiem zariņiem, saknītēm, mizas strēmelītēm, sūnām un citiem augu izcelsmes stiebriem. Ligzdas būvniecībai tiek izmantoti arī audumu gabaliņi, papīrs un spalvas, reizēm tiek izmantoti dubļi. Vietas izvēlē tas nav izvēlīgs, vietās, kur trūkst koku, tas var ligzdu iebūvēt arī lielākā ASV tipa pastkastītē.[6] Jāņem vērā, ka ASV pastkastes ir atšķirīgas no Eiropas pastkastēm. Reizēm tie ieņem citu putnu ligzdas, īpaši bieži tiek ieņemtas ceļotājstrazda (Turdus migratorius) ligzdas.
Zilais sīlis veido monogāmus pārus uz mūžu. Abi kopā būvē ligzdu un audzina pēcnācējus, lai gan olas perē tikai mātīte. Tēviņš timēr baro mātīti. Dējumā ir 4—5 olas. Inkubācijas periods ilgst 16—18 dienas. Putnēniem apspalvojums izaug pēc 17—21 dienas.[7] Kad mazie izlido no ligzdas, visa ģimene līdz ziemai turpina kopā ganīties un baroties. Ziemas periodā, lai izvairītos no sacensībām par barību, jaunie sīļi dodas savas teritorijas meklējumos.
Zilajam sīlim ir 4 pasugas:[1][4]
Zilais sīlis (Cyanocitta cristata) ir vidēja lieluma vārnu dzimtas (Corvidae) putns. Izdala 4 pasugas.
Zilais sīlis ir tipisks Ziemeļamerikas putns. Tā izplatības areāls ir ļoti liels, tas sākas Kanādas dienvidos, aizņem lielas teritorijas ASV vidienē un austrumu krastā, un beidzas Floridas piekrastē un Teksasas ziemeļos. Rietumu robeža zilā sīļa izplatībai robežojas ar sausajiem priežu mežiem. Šie meži ir zilā sīļa tuvākā radinieka Stellera sīļa (Cyanocitta stelleri) izplatības areāla austrumu robeža. Pēdējos gados ziemeļu reģionos zilais sīlis ir ekspandējies uz rietumiem līdz Klusā okeāna krastam. Tā kā mūsdienās abu sugu izplatības areāli ziemeļos pārsedzas, iespējams tās savā starpā reizēm hibridizējas.
De blauwe gaai (Cyanocitta cristata) is een Noord-Amerikaanse soort gaai.
Deze vogel heeft een opvallend lavendelblauw verenkleed op de rug en kop. De veren op het onderlijf zijn gebroken wit, en rond de hals bevindt zich een zwarte kraag. De blauwe gaai wordt ongeveer 30 cm lang.[2]
Het dieet van de blauwe gaai is erg gevarieerd. Op het menu staan onder andere eikels, zaden, bessen, pinda's en brood, maar ook vlees, eieren en kleine ongewervelden.
Iedere geschikte boom of grote struik kan gebruikt worden voor het maken van een nest, waarbij de vogel modder gebruikt. Zowel het mannetje als het vrouwtje werken mee aan de bouw ervan, waarna het vrouwtje de eieren gedurende 16 tot 18 dagen uitbroedt. Vader en moeder brengen samen de kuikens groot. Na drie weken houdt de moeder het voor gezien en moeten de jongen zich zelf zien te redden.
De blauwe gaai komt in een groot deel van de oostelijke helft van de Verenigde Staten voor. Vooral in gemengd bos is de soort talrijk, maar daarnaast komt de soort voor in parken en tuinen.
De soort telt 4 ondersoorten:
Blauwe gaai, ondersoort Cyanocitta cristata cristata in North Carolina
Ondersoort C. c. cyanotephra in DeSoto National Wildlife Refuge, Iowa (staat)
Ondersoort C. c. semplei in Collier County Florida (staat)
Ondersoort C. c. bromia in Muskoka Lakes, Ontario
De blauwe gaai (Cyanocitta cristata) is een Noord-Amerikaanse soort gaai.
Blåskrikje (Cyanocitta cristata) er ein sporvefugl i familien Corvidae som høyrer naturleg heime i Nord Amerika.
Blåskrike (Cyanocitta cristata) er en spurvefugl i familien kråkefugler som er naturlig hjemmehørende i Nord-Amerika.
Denne ornitologirelaterte artikkelen er foreløpig kort eller mangelfull, og du kan hjelpe Wikipedia ved å utvide den. Blåskrike (Cyanocitta cristata) er en spurvefugl i familien kråkefugler som er naturlig hjemmehørende i Nord-Amerika.
Multimedia w Wikimedia Commons Modrosójka błękitna (Cyanocitta cristata) – gatunek średniego ptaka z rodziny krukowatych. Zamieszkuje bardzo duży obszar wschodniej części Ameryki Północnej od Nowej Fundlandii na północnym wschodzie do Florydy na południowym wschodzie, ku zachodowi do Teksasu, poprzez środkową część kontynentu, aż po północ stanu Kolorado. Na zachód od Gór Skalistych występuje jego bliski kuzyn, modrosójka czarnogłowa.
Mimo że ptak ten jest generalnie widziany przez cały rok na zamieszkiwanym obszarze, część osobników z północnych terenów migruje na południowe obszary Ameryki Północnej.
Wyróżniono kilka podgatunków C. cristata[4][2]:
Jest to ptak lasów mieszanych z udziałem buków i dębów, jak również ogrodów i parków w małych miejscowościach i miastach.
Pożywienia poszukuje zarówno na ziemi, jak i wśród drzew. Mocny dziób jest przystosowany do rozłupywania żołędzi, buczyny, nasion chwastów i zbóż czy orzeszków ziemnych, jednak pożywienie zawiera również owoce, mięso, jaja, pisklęta, małe bezkręgowce oraz resztki jedzenia pozostawionego w parkach.
Okres lęgowy trwa od połowy marca do lipca, ale jego szczyt przypada na okres od połowy kwietnia do maja.
Do zagnieżdżenia może być użyte każde odpowiednie drzewo lub duży krzew. Gniazdo jest umieszczane na wysokości od 3 do 10 m, zbudowane w formie czarki z gałązek, korzonków, pasków kory, mchu i innych części roślin, a także skrawków tkanin, papieru i piór.
Samiec i samica budują gniazdo i wysiadują jaja, ale tylko samica opiekuje się pisklętami. Samica zazwyczaj znosi 4-5 jaj i wysiaduje je przez okres 16-18 dni. Młode pierzą się po ok. 17-21 dniach od wyklucia. Ptaki tworzą pary na całe życie.
Modrosójka błękitna jest symbolem kanadyjskiej prowincji Wyspa Księcia Edwarda oraz klubu baseballowego Toronto Blue Jays.
Modrosójka błękitna (Cyanocitta cristata) – gatunek średniego ptaka z rodziny krukowatych. Zamieszkuje bardzo duży obszar wschodniej części Ameryki Północnej od Nowej Fundlandii na północnym wschodzie do Florydy na południowym wschodzie, ku zachodowi do Teksasu, poprzez środkową część kontynentu, aż po północ stanu Kolorado. Na zachód od Gór Skalistych występuje jego bliski kuzyn, modrosójka czarnogłowa.
Mimo że ptak ten jest generalnie widziany przez cały rok na zamieszkiwanym obszarze, część osobników z północnych terenów migruje na południowe obszary Ameryki Północnej.
O gaio-azul (Cyanocitta cristata) é uma ave passeriforme e membro da família dos corvos (Corvidae), que é originária da América do Norte.[1] É uma espécie adaptável, agressiva, e onívora.
O gaio-azul adulto mede cerca de 30 cm desde o bico até à cauda, e pesa aproximadamente 70-100g , com uma envergadura de cerca de 34–43 cm. A sua plumagem é azul na cabeça, no dorso, nas asas, e na cauda. O resto do seu corpo é branco-acinzentado com umas listas pretas na cara, nas pontas das asas, e na cauda. O bico, as patas, e os olhos, são pretos. Tem uma coroa de penas na cabeça, que pode elevar e abaixar de acordo do seu humor. Como nos outros pássaros de cor azul, a coloração do gaio-azul não deriva-se dos pigmentos, mas é resultado da refração da luz nas penas. Se uma pena do gaio azul é esmagada, a cor azul desaparece; a isto chama-se coloração estrutural.
O gaio-azul vive unicamente na América do Norte, desde a parte meridional do Canadá até Texas e Florida. O seu alcance estende-se até as regiões áridas no oeste dos Estados Unidos. Multiplica-se em bosques, parques, e em áreas residenciais.
O gaio-azul é geralmente agressivo e afugenta as outras aves de locais onde há comida. Também tenta afugentar qualquer predador que tente aproximar-se seu ninho, até mesmo as aves de rapina e os humanos. Às vezes, o gaio azul rouba ovos e pintainhos dos ninhos de outros pássaros. Gaios jovens têm tendência a coleccionar objectos brilhantes, como tampas das garrafas, e pedaços de folha de alumínio. Em cativeiro, alguns gaios azuis podem aprender a usar ferramentas para obter comida.
A voz deste pássaro é muito variada, mas o som mais reconhecido é a sinal do alarme, a qual é um grito como o de uma gaivota. Usa este sinal com outros sons altos para afugentar os predadores, como os falcões. Os gaios azuis também usam muitos sons baixos entre eles para comunicarem entre si. Como outros córvidos, os gaios azuis podem imitar muitos sons, até mesmo a voz humana.
Esta ave é omnívora e come quase qualquer coisa que possa obter, tal como sementes, grãos, frutas, bagas, insectos, pão, ovos, carne, etc. Um dos seus alimentos preferidos é a bolota.
A temporada de criação começa no meio de Março e continua até o mês de Julho. Pode construir o seu ninho de paus, musgos, etc. em qualquer árvore ou arbusto, mas as perenifólias são preferidas. Os gaios azuis são monógamos. Ambos os sexos constroem o ninho e criam os filhotes; só a fêmea incuba os 4-5 ovos por 16-18 dias, mas o macho traz-lhe comida durante este tempo. Depois de 17-21 dias, os filhotes saem do ninho, mas todos os elementos da família viajam e procuram comida juntos até ao Outono.
O gaio-azul (Cyanocitta cristata) é uma ave passeriforme e membro da família dos corvos (Corvidae), que é originária da América do Norte. É uma espécie adaptável, agressiva, e onívora.
Gaița albastră (Cyanocitta cristata) este o pasăre cântătoare din familia Corvidae, nativă în America de Nord. Aceasta locuiește tot anul în estul și centrul Statelor Unite și Canada de sud, deși populațiile de vest pot fi migratoare. Se înmulțesc în pădurile de foioase și de conifere, și este comună în apropierea zonelor rezidențiale. Este predominantă albastră, cu un piept alb și, o creastă albastră. Are un guler negru în forma de U în jurul gâtului și niște pene negre în spatele crestei. Sexele sunt similare în mărime și penaj. Patru subspecii de gaiță sunt recunoscute.
Gaița albastră (Cyanocitta cristata) este o pasăre cântătoare din familia Corvidae, nativă în America de Nord. Aceasta locuiește tot anul în estul și centrul Statelor Unite și Canada de sud, deși populațiile de vest pot fi migratoare. Se înmulțesc în pădurile de foioase și de conifere, și este comună în apropierea zonelor rezidențiale. Este predominantă albastră, cu un piept alb și, o creastă albastră. Are un guler negru în forma de U în jurul gâtului și niște pene negre în spatele crestei. Sexele sunt similare în mărime și penaj. Patru subspecii de gaiță sunt recunoscute.
Modra šoja (znanstveno ime Cyanocitta cristata) je ptica pevka in pripadnica družine vranov. Prebiva na območju Severne Amerike.
Modra šoja meri v dolžino od kljuna do repa 22–30 cm in tehta okoli 70–100 g, z razponom peruti od 34–43 cm.[1] Na glavi je prisoten čop, katerega položaj je odvisen od razpoloženja ptice.[2] Perje na čopu, hrbtni strani telesa, krilih in repu je sivkasto modre do srednje modre barve, na obrazu in trebušni strani telesa pa bele barve. Na krilih in repu so prisotni nebesno modri, beli in črni pasovi. Vrat je obrobljen s črnim obročem, ki se razteza na stranska dela glave. Kljun, noge in oči so črne barve. Samci in samice so skorajda enaki, razen tega, da so samci rahlo večji od samic.[3]
Kot pri vseh modro obarvanih pticah tudi pri modri šoji ne daje modre barve pigment v perju, pač pa je ta posledica interference svetlobe zaradi notranje strukture perja, kar imenujemo tudi strukturno obarvanje. Če je modro pero polomljeno, modra barva izgine.
V splošnem so sprejete štiri podvrste modrih šoj, in sicer:[4]
Cyanocitta cristata cristata
C. c. bromia
C. c. cyanotephra
C. c. semplei
Življenjski prostor modre šoje se razteza od južne Kanade, prek vzhodnega in osrednjega področja ZDA do juga Floride in severovzhoda Teksasa.[5] Podvrsta modre šoje C.c. bromia je ptica selivka, ki migrira v južne predele ponoči v skupini od 5-250 ptic. Prebiva v različnih prostorih, kot so borovi gozdovi v Floridi in smrekino-jelkini gozdovi na severu Ontaria. Najrajši prebiva v mešanih gozdovih s hrasti in bukvami, manj pa je prisotna v gostih gozdovih.[2] Zlahka se lahko prilagodi na spremembe okolja zaradi človeške dejavnosti, saj poseljuje med drugim tudi parke in naseljena območja.[6]
Modra šoja leti relativno počasi, tj. 32–40 km/h, če ni izzvana,[7] zaradi česar je lahek plen za sove in sokole na odprtih območjih. V svojem teritoriju se proti plenilcem (kot so sokoli) ter celo proti človeku obnaša agresivno, še posebno v bližini gnezd. Poleg tega se v danem primeru kričeče oglašajo, kar prepoznaju tudi druge manjše ptice in se tako skrijejo na varno.[8] V primeru vznemirjenosti ali agresivnega obnašanja je čop na glavi popolnoma dvignjen, v primeru prestrašenosti je čop obrnjen navzven in v primeru počivanja ali hranjenja v družbi drugih šoj je čop sploščen.[2]
Modra šoja si hrano išče tako na tleh kot tudi v drevesih in vključuje vse znane tipe rastlinskih in živalskih virov, kot so želodi, žiri, semena trav, žito, manjše sadje (npr. jagode), arašidi, kruh, manjši nevretenčarji (še posebej hrošči, kobilice in gosenice) zelo redko pa se poslužuje jajc drugih ptic.[9].
Za strtje in prehranjevanje s semeni, želodi, lešniki idr. imajo razvite močne kljune.
Modre šoje sodijo med bolj inteligentne ptice. Pogosto opazujejo človeka, ki odvrže hrano na tla ali seje žitarice in počakajo, da oddide, nato pa hitro vzamejo ali izkopljejo želen kos hrane. Zaradi plenjenja drugih gnezd imajo slabi ugled med ljudmi, vendar je v resnici pojav zelo redek, kar je v nasprotju s splošnim mnenjem.[9]
Mladi osebki se radi igrajo s predmeti, ki so svetlo obarvani ali odbijajo svetlobo, kot so zamaški steklenic ali kosi alufolije, in jih prenašajo naokoli, dokler se ne naveličajo.[8] Pri nekaterih osebkih v ujetništvu je bilo opaženo, da uporabljajo kose časopisnega papirja kot orodje za pridobivanje hrane.[10]
Paritvena sezona se začne v sredi marca in doseže vrh v sredini aprila do maja, konča pa se v juliju. Pri izbiri gnezdenja ni izbirčna: vsako drevo ali večji grm je primeren, čeprav raje gnezdijo na zimzelenih drevesih. V naseljenih območjih v primeru pomanjkanja ugodnih gnezditvenih mest gnezdijo tudi v večjih poštnih nabiralnikih ali pa se poslužujejo zapuščenih gnezd drugih ptic.[6] Gnezdo kockaste oblike je postavljeno na višini od 3-10 m in je sestavljeno iz vejic, majhnih korenin, lubja, maha in drugega rastlinskega materiala ter iz blaga, papirja in perja, občasno tudi iz blata.
Modre šoje navadno sklenejo posamično zvezo skozi vso življenje (monogamija). Oba partnerja zgradita gnezdo in skrbita mladiče, vendar le samica vali jajca, medtem ko jih hrani samec. Samica običajno izvali 4–5 jajc, valjenje pa poteko 16-18 dni. Mladiči poletijo navadno med 17-21 po izvalitvi.[8] Po tem družina skupno potuje in se hrani do zgodnje jeseni, ko se mladi osebki razkropijo, da bi se izognili tekmovanju za hrano med zimo.
Modra šoja je upodobljena na grbu Otoka princa Edvarda v Kanadi. Eden od večjih baseball klubov v Torontu je imenovan Toronto Blue Jays.
Modra šoja (znanstveno ime Cyanocitta cristata) je ptica pevka in pripadnica družine vranov. Prebiva na območju Severne Amerike.
Blåskrika[2] (Cyanocitta cristata) är en tätting inom familjen kråkfåglar som förekommer i Nordamerika.[3] Den är en anpassningsbar och aggressiv allätare.
Blåskrikan mäter omkring 30 cm från näbb till stjärt och väger 70–100 g. Den har ett vingspann på 34–43 cm.[4] Dess fjäderdräkt är lavendelblå till mellanblå på hjässan, ryggen, vingarna och stjärten, och dess ansikte är vitt. Undersidan är smutsvit och halsen har en svart krage som sträcker sig till huvudets sidor. Vingarnas handpennor och stjärtfjädrarna har kraftiga ränder i svart, himmelsblått och vitt.[5] Näbben, benen och ögonen är helt svarta. Hanar och honor är nästan identiska, men hanarna är något större.[6] Den har en utpräglad tofs på huvudet, en fjäderkrona, som kan resas eller sänkas beroende på fågelns sinnesstämning. När fågeln är upphetsad eller aggressiv kan tofsen ställas rätt upp. När fågeln är skrämd, spretar tofsen utåt, som en borste. När fågeln äter tillsammans med artfränder eller vilar sig, ligger tofsen slätt på huvudet.[7]
Liksom hos andra fåglar med blåa färgtoner, härrör blåskrikans färgning inte från pigment, utan beror på ljusrefraktion på grund av den inre strukturen i fjädrarna. Om en blå fjäder krossas, försvinner det blåa eftersom strukturen är förstörd.
Blåskrikan förekommer från södra Kanada söderut till Texas och Florida. Den häckar i blandskog, lövfällande skog, parker och bostadsområden från Kanada i norr, över östra Nordamerika och söderut till Florida och nordöstra Texas. Utbredningsområdets västra kant slutar där den torra tallskogen och busklandet som är biotop för den närbesläktade stellerskrikan börjar. Nyligen har blåskrikans utbredning utvidgats åt nordväst så att den nu är en regelbunden men ännu ovanlig höstflyttare längs norra Stillahavskusten.[4]
Blåskrikan delas in i fyra underarter med följande utbredning:[8]
Blåskrikan är delvis flyttfågel. Den kan flytta flera hundra kilometer söderut i de nordligaste delarna av utbredningen. Den flyttar på dagtid i löst hållna flockar om 5 till 250 fåglar.[5] Blåskrikan bebor många olika biotoper inom dess stora utbredningsområde, från tallskogarna i Florida till gran- och ädelgranskogarna i norra Ontario. Den är mindre vanlig i de tätare skogarna och föredrar blandade skogslandskap med ekar och bokar.[7]
Blåskrikan är vanligen aggressiv mot andra fåglar, och jagar fåglar från fågelbord eller andra födokällor. Den kan jaga rovfåglar, såsom hökar och ugglor, som emellanåt tar blåskrikor, och skriker om den ser en predator inom sitt territorium. Blåskrikan kan också vara aggressiv mot människor som kommer nära dess bo, och om en uggla vilar nära boet på dagen attackerar blåskrikan den tills den tar sig en ny viloplats. Blåskrikan flyger långsamt och är ett lätt byte för hökar och ugglor när den flyger i öppna landskap. Den flyger med kropp och stjärt hållna parallellt, med långsamma vingslag.[9]
Blåskrikan är känd för att plundra andra fåglars bon. Den kan stjäla ägg, ungar och bon. Den tar över bon från vandringstrast. Unga blåskrikor samlar bjärt färgade eller reflekterande föremål, som kapsyler eller bitar av aluminiumfolie, och bär dem en stund.[9]
Blåskrikor i fångenskap har setts använda remsor av tidningspapper som verktyg för att få tag på föda.[10]
Lätet är liksom hos de flesta närbesläktade arter varierat, men det mest igenkända lätet är varningslätet, som är ett högljutt, nästan mås-likt skrik. Det förekommer också ett gällt jayer-jayer-läte som tilltar i hastighet när fågeln blir mer uppjagad. Blåskrikor använder dessa läten för att hålla samman och driva bort rovdjur som hökar från boet.
Blåskrikor har också tysta, nästan subliminala läten som de använder när de befinner sig nära varandra. Ett av de mest distinkta lätena av denna typ beskrivs ofta som den "rostiga pumpen" på grund av dess likhet med ljudet av en gammaldags handdriven vattenpump. Faktum är att de kan utföra en stor mångfald olika läten och det kan förekomma stora skillnader i stil mellan olika individer. Liksom andra kråkfåglar, kan blåskrikor lära sig att härma mänskligt tal.[11]
Födan söks både på marken och i träd och består av nästan alla kända typer av växt- och djurkällor, såsom ekollon och bokollon, gräsfrön, utsäde, frukter och andra bär, jordnötter, bröd, kött, ägg och ungar, små ryggradslösa djur av många sorter, smulor i parker och mat på fågelbord. Blåskrikor plundrar också andra fåglars bon för att attackera deras ungar.
Häckningssäsongen börjar i mitten av mars, får sin höjdpunkt i april till maj och fortsätter in i juli. Vilket lämpligt träd eller större buske som helst kan användas för häckningen, men en städsegrön föredras, och boet byggs på 3 till 10 meters höjd. Föräldrarna bygger ett koppformat bo av grenar, små rötter, barkremsor, mossa, annat växtmaterial, tyg, papper och fjädrar, ibland med lera tillsatt koppen.[12]
Båda könen bygger boet och uppfostrar ungarna, men bara honan ruvar dem. Hanen utfodrar honan medan hon ruvar på äggen. Vanligtvis läggs 4–5 ägg som ruvas i 16–18 dagar. Ungarna blir vanligen flygga efter 17–21 dagar. Blåskrikor bildar oftast livslånga monogama par.[9] När ungarna har blivit flygga, färdas och födosöker familjen tillsammans till början av hösten.[12]
Ontario, Canada
Blåskrika (Cyanocitta cristata) är en tätting inom familjen kråkfåglar som förekommer i Nordamerika. Den är en anpassningsbar och aggressiv allätare.
Mavi alakarga (Cyanocitta cristata), kargagiller (Corvidae) familyasından genelde Kuzey Amerika'da bulunan bir alakarga türü.
Mavi alakarganın kafasından kuyruğuna kadar açık maviden orta-maviye kadar renkler bulunur. Kafasında da bir ibiği vardır. Renginin kanatlarını açıp uçarken siyaha, gök mavisine ve beyaza doğru dönüştüğü görülür. Altı beyazdır; boynuna doğru da bu renk koyulaşır. Boyu 28 cm olup, kanat aralığı 42 cm'dir. 52 gr ağırlığındadır.
Kuzey Amerika'nın orta ve doğu bölgelerinde oldukça sıklıkla görülen mavi alakargalar, kuzeyde Kanada'nın güneyinden başlayarak ABD'nin doğu ve orta bölgelerinden güneye doğru Florida ve Kuzeydoğu Teksas'a kadar olan geniş bir alanda yaşarlar. Genelde ağaçlık alanlarda yaşarlar, ancak parklarda ve bazı şehirlerde de gözükürler. Batıya gittikçe daha değişik alakarga türleriyle karşılaşılır.
Yedikleri besinler arasında; yerden ve ağaçlardan alınabilecek birçok tür bulunmaktadır. Bilinenler arasında ekmek, et, yumurta, fıstık, çilekler ve diğer meyveler, tohumlar ve birçok şehir parklarında kuş masası yemeklerini yerler.
Nadiren yem verilirken agresif davranabilirler, lakin bazen diğer kuşların yuvalarını ve yumurtalarını yok ederler. Bu yüzden kuşları doyuranlar tarafından uygun karşılanmazlar. Yine de, bu zeki ve yaşama adapte olabilen kuşlar yaşamda kalabilirler ve insanlara alışkınlardır. Genelde çekirdek ve cevizleri çok severler.
Herhangi bir ağaçta veyahut da ovukta gençlikleri itibarıyla rahatlıkla kalabilir ve buralarda büyüyebilirler. Genelde 16-18 günlük bir periyotta, 4-5 yumurta bırakırlar. Mavi alakargalar genelde ömürlerinin tamamı boyunca tek eşli yaşarlar.
Her ne kadar yıl boyunca bu kuşlar genelde aynı yerde kalsa da, bazı kuzey kuşları güneye doğru göç ederler ve bu yolculuklarıını gün içinde yaşarlar.
Sesleri diğer kargalardan daha farklıdır, ama genelde bir alarm sesi gibi, oldukça gürültülü ve martı çığlığına benzer. Ayrıca kuş, kızması durumunda daha da yüksek bir ses çıkartabilir. Mavi alakargalar genellikle bu sesleri şahinlerden korunmak için çıkartırlar.
Mavi alakargalar ayrıca sessiz, birbirlerine yakınken çağırma şekilleri de vardır. Lakin, birçok sesi çıkartabilirler ve birçok kişi seslerini tanıyamayabilir.
Renkleri kimyasal değildir, tüylerinin şekli itibarıyla ışığın kırılmasından dolayıdır. Eğer ki, bir mavi alakarganın tüylerini kırarsanız mavi renk yok olur. Bu şekilsel renklenme olarak bilinir.
Mavi alakargalar ayrıca, Prens Edward Adası'nın resmi kuşudur ve şehrin beyzbol takımı Toronto mavi alakargası ismini verir.
Bu kuşlar evcilleştirmek istenilirse ya da bir yere hapsedilirse, diğer kuşlara karşı saldırgan olurlar. Aralarında birlik olur ve diğer herkese saldırırlar.
Mavi alakarga (Cyanocitta cristata), kargagiller (Corvidae) familyasından genelde Kuzey Amerika'da bulunan bir alakarga türü.
Це незавершена стаття з орнітології.Giẻ cùi lam (Cyanocitta cristata) là một loài chim thuộc họ Quạ, là loài bản địa của Bắc Mỹ. Chúng sống ở khắp miền Đông và Trung Hoa Kỳ và miền Nam Canada, những cá thể sống ở miền Tây có thể di cư. Loài này sinh sản trong các khu rừng rụng lá và rừng tùng bách, và thường gần các khu dân cư. Chúng thường có màu lam với ức và bụng màu trắng, và mào màu lam. Nó có vòng lông hình chữ U màu đen quanh cổ và viền đen sau mào. Không có sự khác biệt về kích thước và bộ lông giữa con đực và cái, và bộ lông không thay đổi trong năm. Có 4 phụ loài của loài này đã được ghi nhận.
Giẻ cùi lam ăn chủ yếu là các loại hạt, cây sồi, trái cây mềm, động vật chân đốt, và thỉnh thoảng ăn các loài động vật có xương sống nhỏ. Chúng đặc biệt nhặt thức ăn từ cây, cây bụi, và trên mặt đất, mặc dù đôi khi săn bắt côn trùng. Cả chim bố và mẹ cùng xây tổ hình chiếc cốc hở trên nhánh cây. Tổ có thể chứa 2 đến 7 trứng, các trứng có màu lam hoặc nâu nhạt với các đốm màu nâu. Chim mới nở được mẹ mớm mồi trong vòng 8-12 ngày. Chúng ở trong tổ cùng chim bố mẹ trong vòng 1 đến 2 tháng trước khi rời tổ.
Có 4 phân loài đã được mô tả. Không có ranh giới rõ ràng giữa các phụ loài trên đất liền. Dải phân bố của các nhóm ven biển được xác định rõ hơn.[1][2]
Cyanocitta cristata cristata màu sáng ở quận Johnston, North Carolina
A C. c. cyanotephra ở Khu trú ẩn động vật hoang dã quốc gia DeSoto, Iowa
C. c. semplei, dạng nhỏ, ở quận Collier, Florida
C. c. bromia ở Muskoka Lakes, Ontario
Giẻ cùi lam (Cyanocitta cristata) là một loài chim thuộc họ Quạ, là loài bản địa của Bắc Mỹ. Chúng sống ở khắp miền Đông và Trung Hoa Kỳ và miền Nam Canada, những cá thể sống ở miền Tây có thể di cư. Loài này sinh sản trong các khu rừng rụng lá và rừng tùng bách, và thường gần các khu dân cư. Chúng thường có màu lam với ức và bụng màu trắng, và mào màu lam. Nó có vòng lông hình chữ U màu đen quanh cổ và viền đen sau mào. Không có sự khác biệt về kích thước và bộ lông giữa con đực và cái, và bộ lông không thay đổi trong năm. Có 4 phụ loài của loài này đã được ghi nhận.
Giẻ cùi lam ăn chủ yếu là các loại hạt, cây sồi, trái cây mềm, động vật chân đốt, và thỉnh thoảng ăn các loài động vật có xương sống nhỏ. Chúng đặc biệt nhặt thức ăn từ cây, cây bụi, và trên mặt đất, mặc dù đôi khi săn bắt côn trùng. Cả chim bố và mẹ cùng xây tổ hình chiếc cốc hở trên nhánh cây. Tổ có thể chứa 2 đến 7 trứng, các trứng có màu lam hoặc nâu nhạt với các đốm màu nâu. Chim mới nở được mẹ mớm mồi trong vòng 8-12 ngày. Chúng ở trong tổ cùng chim bố mẹ trong vòng 1 đến 2 tháng trước khi rời tổ.
Cyanocitta cristata (Linnaeus, 1758)
Ареал
Голубая сойка[1] (лат. Cyanocitta cristata) — певчая птица из семейства врановых (Corvidae). Обитает в Северной Америке.
Размер голубой сойки составляет около 30 см, а размах крыльев насчитывает около 42 см. Её вес составляет от 70 до 100 г. Характерным признаком является голубая спинка, короткий синий гребешок, чёрное ожерелье, сине-чёрно-белый узор на крыльях и чёрно-белый полосатый хвост.
Голубые сойки живут в парах или в небольших семейных группах. При перелёте образуют большие стаи. Умеют издавать множество различных звуков, а также подражать звукам других птиц, в том числе и хищных. Благодаря этому они предупреждают сородичей об опасности и отпугивают вторгнувшихся в их ареал.
Голубая сойка обыскивает землю, стараясь найти орехи, семена, ягоды, насекомых или других мелких животных. Она откладывает запас на зиму в дуплах деревьев или в земле и вносит существенный вклад в распространение кустов и деревьев. Считается разорительницей гнёзд, так как в весенний период поедает яйца и птенцов других птиц.
Голубые сойки ведут моногамный образ жизни и остаются верны своему партнёру на протяжении всей жизни. Оба родителя сооружают на деревьях или в кустах не очень опрятно выглядещее гнездо из веток, травы и стеблей. Насиживанием занимается только самка. Дважды в году она около 17 дней греет отложенные 3-6 яиц, имеющие зеленоватые или коричневые вкрапления. Спустя двадцать дней после рождения молодые птенцы начинают летать.
Ареал голубой сойки простирается от востока США и юга Канады до Мексиканского залива. По-английски эта птица называется Blue Jay. Голубая сойка является перелётной птицей лишь отчасти: перелёт на юг в зимнее время совершают только северные популяции. Изначально будучи обитательницей лиственных лесов, голубая сойка зимой встречается и в культивированных местностях, в деревнях, парках и пригородах. В западной части Северной Америки распространена только её близкая родственница, стеллерова черноголовая голубая сойка (Cyanocitta stelleri).
Голубая сойка (лат. Cyanocitta cristata) — певчая птица из семейства врановых (Corvidae). Обитает в Северной Америке.
冠蓝鸦（英文：blue jay 学名：Cyanocitta cristata），又名蓝松鸦、藍樫鳥，是雀形目鸦科冠蓝鸦属的鸟类，原产於北美洲，主要分布於美国落基山脉以东、圣皮埃尔和密克隆群岛和加拿大南部，属於新北界松鸦，与其他的鸦科亲缘关系较远，而在北美洲松鸦中，只有冠蓝鸦和暗冠蓝鸦有顶冠。它们适应性强，好奇好斗，聪明顽皮，杂食性，在几十年中已被引入多个新栖息地。冠蓝鸦的外表非常引人注目，这就有利於人们发现它们，观察它们迷人的外表和姿态。
种加词cristata为拉丁语，意为“有顶冠的”，属名Cyanocitta来自希腊语，由cyanos（κυανοϛ）和citta（κίττα）两部分组成，两者的意思分别为“蓝色的”和“鸟”[2]。
冠蓝鸦的分布区包括加拿大南部，延伸至美国东部和中部，南界至佛罗里达州和得克萨斯州东北部。分布区西界为落基山脉以东，是其近缘种暗冠蓝鸦（Cyanocitta stelleri）的分布区边界，这些区域覆盖着干旱针叶林和灌木，是它们共同的栖息地，落基山脉以西是暗冠蓝鸦的分布区，不过它们的栖息地与冠蓝鸦的栖息地类似。近年来，冠蓝鸦的分布范围向西北方向扩张，这样一来，它们在美国北部和加拿大南部的太平洋沿岸虽然很少见，但却是定期出现的越冬鸟类[3]，而加利福尼亚州曾出现迷鸟。由於目前冠蓝鸦和暗冠蓝鸦的分布区重叠，它们有时会相互杂交[4]。它们的繁殖区包括艾伯塔中部、薩斯喀徹溫及曼尼托巴南部，东至安大略省中部和南部以及魁北克南部、纽芬兰岛、新不倫瑞克、爱德华王子岛和新斯科舍。在冠蓝鸦分布区的最北端，人们可能会同时看到冠蓝鸦和灰噪鸦（Perisoreus canadensis），灰噪鸦这种鸟在林木線以北很远的地区繁殖。在佛罗里达州中部，冠蓝鸦与丛鸦（Aphelocoma coerulescens）共存。[2]
在广大的分布区中，冠蓝鸦生活在多种不同类型的栖息地，包括佛罗里达州的松林和安大略省的云冷杉林。它们偏爱包括橡树和山毛榉的混合林，而在较为茂密的森林中要相对少见[2]。它们对人类活动已经习以为常，时常出现在公园和住宅区，特别是有喂食器和橡树的地方[3]。如果森林被砍伐後，人类活动能为它们创造其他的生活环境，它们就能较好地适应大规模的森林開伐[5]。
冠蓝鸦从喙至尾体长22－30厘米，重70－100克，翼展34－43厘米[3][6]。顶冠明显，可受它们心情的影响而升降。当它们兴奋、进攻和求偶时，顶冠会高高立起；受到惊吓时，顶冠会如毛刷一般四面张开；而当它们与其他北美洲松鸦一起觅食或休息时，顶冠是平铺在头顶上的[2]。在求偶和飞行中，当它们表示服从时，它们会蹲下并抖松羽毛，并立起顶冠[6]。
它们顶冠的羽色为薰衣草蓝或淡蓝色，颈后、翅膀内侧、尾羽内侧和面部为白色。腹部为米白色，颈部有黑色领环，延伸至面部两侧，这些黑色部分的形态有很大的个体差异，有助於冠蓝鸦互相辨认。初级飞羽和尾羽主要为天蓝色，并有明显的黑色和白色线条。喙、腿和眼睛均为黑色。雄鸟和雌鸟外形几乎完全相同，只不过雄鸟体型稍大[7][6]。它们的喙很强壮，能咬开坚果和橡子，这样就可以吃谷物和种子，不过它们也觅食昆虫，如甲虫、蚱蜢和毛虫。
与其他蓝色调的鸟类一样，冠蓝鸦的蓝色并不是由色素显现，而是由於光在羽毛内部发生干涉而导致的结果，如果蓝色羽毛被碾碎的话，由於内部结构被破坏，蓝色就消失了，而是会显现出羽毛本身由黑色素显现出的棕褐色[3]。由这种方式显现出的颜色被称为结构色彩。
冠蓝鸦飞行速度不算快，平常时速约为32－40千米/小时（9－11米/秒）[8]，在开阔的地面时能被鹰和猫头鹰捕获。飞行时，它们身体和尾保持水平，翅膀缓慢的拍打[3]。
它们被认为是森林和城镇中的一道风景线，如鸟类学家奥杜邦所说：“它们翅膀的运动姿态非常优美，从一棵树飞到另一棵树；它们展开双翅和尾羽，展示出它们优美的体型，动人的色泽，它们所有的美丽，从来不会使观鸟者扫兴。”[9]
已知最长寿的环志过的野生冠蓝鸦的寿命达到至少17年6个月[3]，一般的野生冠蓝鸦寿命为10－15年[2]，而一只家养雌性冠蓝鸦寿命达到了26年3个月[6]。
冠蓝鸦可以发出很多种不同的声音，而不同个体的鸣叫方式也是较为明显的。像其他鸦科一样，它们能模仿人类的说话声。冠蓝鸦也能模仿它们栖息地中的鹰的鸣叫声，因此有时不易分辨出它们[10]。它们最常模仿赤肩鵟（Buteo lineatus）的鸣叫声，这样做是为了告知周围的冠蓝鸦老鹰在附近，或是欺骗其他的动物以使它们相信老鹰就要来了[3]。它们的鸣叫声变化多端，在大多数北美洲松鸦中可算得上是很典型，不过它们的警鸣还是很容易辨别出的。它们的警报叫声很巨大，很像鷗的尖厉鸣叫。它们还能发出高声调的jayer-jayer声，而它们焦躁不安的时候频率会加快。这种特别的鸣叫声很容易和山雀的慢速起始鸣叫声chick-ah-dee-ee混淆。冠蓝鸦会利用这些鸣叫声和拟攻行为驱走如鹰一类的潜在天敌，防止它们接近自己的巢。
冠蓝鸦在近距离交流时也会使用极为安静的叫声，几乎是人类难以察觉的，包括咔咔、咯咯、嗡嗡、嘎嘎以及铃声等声音。这类叫声中最有特点的一种被称为“生锈的水泵声”，因为这种声音像古旧的手动水泵声。在春天，它们会发出轻柔的鸣啭。包括冠蓝鸦在内的鸦科鸟类与其他鸣禽相比很独特，因为它们能利用鸣叫声制造出非常复杂的鸣啭。一次鸣啭可能会超过2分钟。[3][6]
在美国的大部分地区，人们在一年中常常能听到它们飞翔时发出的高声鸣叫，而在秋季它们鸣叫得更为频繁。在分布区北部，到了冬季，大多数鸟类都已南迁，它们的叫声就显得更为突出。[11]
一般认为冠蓝鸦有4个亚种，不过这个物种中的亚种差异是非常细微的，本质上来说是渐变群。内陆亚种的分布区没有明显的区分界限，而沿岸亚种的分布区界限较为明确[7]。
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Cyanocitta cristata cristata，摄於北卡羅萊納州約翰斯頓縣。 C. c. bromia警觉地伫立着，摄於安大略省马斯科卡湖镇。 C. c. cyanotephra放松地栖息在断木上，摄於艾奥瓦州迪索托国家野生生物保护区（DeSoto National Wildlife Refuge）。 C. c. semplei，摄於佛罗里达州柯里爾縣。 它们会在地面和树上觅食，食物类型多种多样，实际上包括各种类型的植物和动物来源，如橡子和山毛榉坚果、野草籽、谷物、水果、浆果、花生、面包、肉类、多种小型无脊椎动物、城镇公园内的剩饭、鸟类喂食器中寻找食物，极少数情况下还会食用鸟蛋和雏鸟，以及死亡或将死的成年冠蓝鸦。很多人不喜欢冠蓝鸦是因为它们会吃其他鸟类的蛋和雏鸟。然而，一项关於冠蓝鸦食性的详细研究表明，仅能证实1%的冠蓝鸦的胃中有蛋或雏鸟，它們最主要的食物實際上是堅果和昆蟲。它们捕食同类的行为不应受到谴责，因为这是它们控制种群数量的一种方式。[2]
它们的食物构成中昆虫占了约22%，其余基本上是各种果实和种子。它们喜爱橡子，并会选择完整的、没有被象鼻虫咬坏的橡子埋在地下，或是藏在草丛或树洞中。它们一次能运送4－5枚橡子，2－3枚在喉囊中，1枚在嘴里，而喙端亦能夹住1枚。一只冠蓝鸦在秋季一季内可运送3000－5000枚橡子。它们的这些行动功不可没，因为这些行动使得橡树在末次冰期分布得更为广泛。[3]它们有时还会储存大量食物以备今後食用，而这种行为对环境是有益的，因为它们将食物藏好後，有时会忘记食用，这样它们的行为就有助於植物的传播[6]。冬季，冠蓝鸦会将食物，尤其是面包和葵花籽从饲喂站定期运走，然後藏在树下和灌木丛中，以备以後食用。定期的花生、混合谷物特别是葵花籽供应能将它们吸引到饲喂架上。它们喜欢用爪抓住坚果，然後将壳啄开，吃里面的果仁。
冠蓝鸦在控制害虫天幕毛虫（Malacosoma）方面也起到了很大作用。一对冠蓝鸦可以一次吃掉上百个蛹或毛虫，而这些蛹在夏初就会破茧而出。冠蓝鸦伴侣会啄开坚韧丝质的茧，并将其中的幼虫存在喉囊中，每次会为雏鸟带去多条幼虫。它们的这种行为消灭了来年春天将会孵化的上千个卵，无疑为控制害虫作出了不小的贡献。[2]
它们有时对其他鸟类非常不友好，会把其他鸟类从喂食器或其他食物源逐走，不过这种情况不常发生，因为在这种情况下它们往往会被人们责备。而且在佛罗里达州，红头啄木鸟（Melanerpes erythrocephalus）、佛羅里達灌叢鴉（Aphelocoma coerulescens）、普通拟八哥（Quiscalus quiscula）和灰松鼠常在鸟类喂食器附近与冠蓝鸦作对，阻碍它们获得食物，而山齒鶉、哀鸽、白翅哀鸽（Zenaida asiatica）、小嘲鶇（Mimus polyglottos）和北美红雀（Cardinalis cardinaliss）偶尔也会这样做。为了对付它们，冠蓝鸦会模仿鹰的鸣叫以吓跑它们，不过当它开始进餐时，它们又会回来与它争抢。它们还会利用不同的手段吓唬其他鸟类，如此一来这些鸟就会因为惊吓而丢下自己的食物，这样冠蓝鸦就能将它们的食物偷走。[3][6]
生活在最北端的亚种C. c. bromia是候鸟，这是由於生存的需要。它们可能会从分布区的最北端向南飞行几百公里，但是即使是生活在北方的鸟类也不会都像它们一样南迁，而在冬季较为温和且食物充足的年份里更是不会这样做。它们在白天迁徙，结成5－250只鸟组成的松散集群，而在历史上，曾有3000多只冠蓝鸦聚集在一起迁徙，这样的情况发生在霹雳角国家公园（Point Pelee National Park），当时这些冠蓝鸦将要越过伊利湖[2]。
只有少於20%的冠蓝鸦会迁徙，而在这些冠蓝鸦中，除了分布在佛罗里达的冠蓝鸦基本为留鸟，有些个体会常驻在一个地方，而有些个体又会常常迁徙，而这些迁徙的冠蓝鸦包括各个年龄段，毫无规律。不过一般来说，幼年冠蓝鸦比成年冠蓝鸦迁徙更为频繁[3]。因此，虽然冠蓝鸦在北美是一种很常见的鸟类，而且关於它们的研究也开展了很多，但至今它们迁徙的原因仍是一个谜。[3]
冠蓝鸦会积极的进行主动防御，当鹰、隼、浣熊、蛇、松鼠甚至人类接近它们的巢时，雄鸟和雌鸟都会攻击和驱赶它们。成年冠蓝鸦最主要的天敌是鹰、猫头鹰和隼，雏鸟的天敌包括松鼠、猫、蛇、美国乌鸦（Corvus brachyrhynchos）、其他北美洲松鸦、浣熊、負鼠以及鹰等掠食性鸟类。
冠蓝鸦对其他物种也是有益的，因为它们可以驱赶鸟类掠食者，如鹰和猫头鹰这些偶尔会捕食冠蓝鸦的鸟类，当它们发现天敌入侵自己的领区时就会尖厉的鸣叫。当鹰接近或其他危险来临时，它们能发出警鸣，这样小型鸟类就能辨别这种鸣叫声，然後寻找藏身之处。当人类接近它们的巢时，它们会展现出进攻的姿态，而当白天猫头鹰接近时，它们会对猫头鹰进行拟攻直到猫头鹰离开[12]。
在换羽期中，冠蓝鸦会进行蚁浴，即利用蚂蚁清理身上羽毛中的污物和寄生虫。进行蚁浴的冠蓝鸦会非常激动，它们会将翅膀张开，并且用喙叼着蚂蚁翼的腹面沿着飞羽疯狂的向下擦拭。近期的研究表明，之所以它们有这种特别的举动，原因是因为新羽毛的生长会刺激皮肤，也许蚂蚁的分泌物如蚁酸等能减轻这种痛苦。它们也会利用替代品来代替蚂蚁进行蚁浴，如水果、烟草、芥末和醋。冠蓝鸦饲养者曾发现有冠蓝鸦用酸腐的果酱和护发素混在一起进行“蚁浴”，还有冠蓝鸦只用护发素，有的冠蓝鸦甚至将点燃的香烟擦拭羽毛，它们这种奇怪的行为需要更多的研究。[2]
冠蓝鸦的交配期始於3月中旬，在4月中旬至5月达到高潮，至7月才结束。任何适宜的树或大灌木丛都可被用来筑巢，不过它们更喜爱常绿植物。它们会倾向於把巢修筑在3－10米的高度，雄鸟和雌鸟都会参与修筑巢穴，不过雄鸟主要是收集巢材，雌鸟主要是筑巢。巢为大杯状，外径约18厘米，内径约10厘米，巢材包括小枝、小根、树皮条、苔藓、其他植物材料、布片、纸片和羽毛，另外它们会用软泥将巢内部修整成小杯状，而在所有的北美洲松鸦中，只有它们和暗冠蓝鸦会将软泥用於筑巢。它们会努力地把小枝都材料弄断，以便更好的利用。为了收集材料，它们不惜远距离飞行，不过如果附近有强势的天敌，它们可能会弃巢而逃。[3]
它们对筑巢地点不太挑剔。如果没有太好的筑巢地点，如当地的森林被严重砍伐时，它们甚至会选择如大信箱作为筑巢地点，这种情况在美国乡村地区很典型。[5]。在找到合适的筑巢地点前，它们也可能会占用其他鸣禽的巢，如旋鸫（Turdus migratorius）的巢常被冠蓝鸦占用。筑巢一般从4月中旬开始，5月初就会开始产卵[13]。
冠蓝鸦有复杂的社会体系，是典型的终身一夫一妻制鸟类。一些冠蓝鸦在求偶期间会直挺挺地在树枝间跳来跳去，不过人们对於它们的求偶习性知之甚少。虽然很多鸟类在孵蛋时都有雄鸟喂养雌鸟的情况，但是冠蓝鸦从求偶期间开始就有这种行为，它们会飞到雄鸟附近，然後像雏鸟一样作出祈求食物的姿势，这样雄鸟就会饲喂它们。两性都会筑巢并抚养幼鸟，不过只有雌鸟会孵蛋。[2]北方的冠蓝鸦一年只会产1窝蛋，而生活在南方的冠蓝鸦一年会产2－3窝蛋[14]。一窝2－7枚蛋，不过一般是4－5枚蛋，每一窝蛋都可能有不同的颜色，可能是淡黄色、淡绿色或淡蓝色，上面有棕褐色或橄榄色的斑点或色块。每个蛋长2.5－3.3厘米，直径1.8－2.2厘米。当雌鸟孵蛋时，雄鸟会将食物喂食给雌鸟，16－18日之後就会孵化。刚出生的雏鸟双目紧闭，全身无毛，嘴喙线为红色，非常无助，它们如果听到鸟降落在巢边的声音，就会张开小嘴，等待父母喂给它们食物。雏鸟在出生17－21日之间会长出羽毛[12]，如果在此之前它们就出巢，原因可能受到外界干扰。在长出羽毛的1－3日前，个别雏鸟可能会离开巢远达5米，在附近徘徊，这时即使它如何大声祈求父母喂食，父母也不会理睬它，除非它归巢。这段时期人们常常会发现被丢弃的雏鸟，就是由於这个原因，不过如果这些雏鸟能归巢或者被放到巢附近，成年冠蓝鸦就会继续喂养它们。离巢後的第二天，幼鸟就能离开父母23米以外的距离。孵化一个月之後幼鸟就能自己觅食，不过成年冠蓝鸦仍会至少喂养幼鸟一个月或两个月，有时甚至会达到四个月，这取决於幼鸟独立的程度。[3]幼鸟长出羽毛後，冠蓝鸦全家会一起行动和觅食，到初秋时幼鸟就会各奔东西，这是为了避免在冬季时互相争夺食物。[2]
冠蓝鸦是最聪明的鸟类之一。它们会等待并观察人，直到人把食物放下并走远後，它们才会俯冲下去窃走食物。冠蓝鸦也会同乌鸦一起观察人类播种，当人走後它们就会挖出并吃下种子。冠蓝鸦是领地观念很强的鸟类，它们会赶走喂食器附近的其他鸟以便更轻松地享受美餐。冠蓝鸦名声不好，因为它们会侵占其他鸟类的巢，窃取其他鸟类的卵、幼雏和巢。不过，这种情况实际上并不像人们所想的那么普遍[3]。
像其他的鸦科一样，冠蓝鸦是非常好奇、聪慧的一种鸟。年轻的冠蓝鸦会高兴的夺取颜色鲜艳或反光的物体，如瓶盖或铝箔，然後带着这些东西到处闲逛，直到它们失去兴趣时才会扔掉这些东西[12]。人们已观察到，圈养的冠蓝鸦能以报纸条作为工具获得食物[15]。
冠蓝鸦的分布区广大，达到约670万平方千米，数量约为2200万只，而且数量目前仍在增长，因此被IUCN评为无危[1]。它们与人类和谐相处，不过主要的死因是受到家猫和狗的攻击[3]。它们对人类生活基本没有直接的影响，唯一的危害就是它们有可能作为西尼羅河病毒的传播者，因为鸦科较容易感染这种病毒[6]。目前冠蓝鸦不受大多数法律保护，不过一些地区会有地方性法律保护它们[2]。
冠蓝鸦是加拿大愛德華王子島的省鸟。冠蓝鸦已被许多运动团体作为吉祥物，如多伦多的美国职棒大联盟棒球队多倫多藍鳥（Toronto Blue Jays）就是以冠蓝鸦（Blue Jay）命名的[6]。冠蓝鸦也是约翰·霍普金斯大学体育队和克雷顿大学体育队的吉祥物。
此外，卡通頻道動畫「天兵公園」的主角鳥哥亦是以冠藍鴉為原型設計的。
在美国南部黑人的民间传说中，冠蓝鸦是魔王的仆人。人们在星期五不会见到他，因为他被禁锢在地狱中，不过，一旦星期六来临，他会非常高兴快活，因为他从地狱中被释放了出来[16]。
冠蓝鸦（英文：blue jay 学名：Cyanocitta cristata），又名蓝松鸦、藍樫鳥，是雀形目鸦科冠蓝鸦属的鸟类，原产於北美洲，主要分布於美国落基山脉以东、圣皮埃尔和密克隆群岛和加拿大南部，属於新北界松鸦，与其他的鸦科亲缘关系较远，而在北美洲松鸦中，只有冠蓝鸦和暗冠蓝鸦有顶冠。它们适应性强，好奇好斗，聪明顽皮，杂食性，在几十年中已被引入多个新栖息地。冠蓝鸦的外表非常引人注目，这就有利於人们发现它们，观察它们迷人的外表和姿态。
种加词cristata为拉丁语，意为“有顶冠的”，属名Cyanocitta来自希腊语，由cyanos（κυανοϛ）和citta（κίττα）两部分组成，两者的意思分别为“蓝色的”和“鸟”。
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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 : スズメ目 Passeriformes 科 : カラス科 Corvidae 属 : Cyanocitta 種 : アオカケス C. cristata 学名 Cyanocitta cristata (Linnaeus, 1758)[1] 和名 アオカケス 英名 Blue jay 
アオカケス（Cyanocitta cristata）は、スズメ目カラス科に分類される鳥類。
多くの地域では渡りは行わないが、カナダに分布する個体群は冬になると南下することもある。
全長30センチメートル。英名や和名の通り頭頂部や背面、尾羽は鮮やかな青い羽毛で覆われる。種小名cristataは「鶏冠のある」の意で、名前の通り頭頂の冠羽は発達する。頭部は黒く、眼の周囲や喉は白い。下面は灰色。翼、尾羽の先端は白い。
森林や農耕地・市街地などに生息する。ペアで縄張りを形成して生活する。英名jayは「ジェイ、ジェイ」と聞こえる鳴き声に由来するが、猛禽類の鳴き声を真似て威嚇などに用いることもある。
食性は雑食で、昆虫、節足動物、鳥類の卵や雛、果実、種子などを食べる。食物を貯蔵するが、これには縄張り内の餌をなくすことで侵入者を減らす働きがあると考えられている。
繁殖様式は卵生。樹木の上に木の枝や草の茎、樹木の細い根などを組み合わせた巣を作る。建物の上に営巣することもある。1腹2 - 6個の卵を産む。抱卵は雌が行い、抱卵期間は16 - 18日である。
適応力が強く市街地等でも見かけられるため、人間にとって身近な鳥類といえる。
オンタリオ州を代表する鳥とされ、メジャーリーグの球団トロント・ブルージェイズにその名前が使われている。
この項目は、鳥類に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（ポータル鳥類 - PJ鳥類）。
파랑어치(학명: Cyanocitta cristata) 또는 블루 제이(영어: blue jay)는 북아메리카에 서식하는 까마귀과의 철새이다. 미국 중동부 대부분의 지역에서 서식하며, 서부 개체들은 이주를 할 수 있다.
영어명인 블루 제이는 시끄럽고 수다스러운 본성 때문에 지어졌다.[1] 영어권에서는 종종 "제이버드"(jaybird)라고도 부른다.[2]
파랑어치는 부리에서 꼬리까지 22~30 세티미터(9~12인치), 무게는 70~100 그램(2.5~3.5 oz), 날개 길이는 34~43 세티미터(13~17인치)에 이른다.[3][4]
파랑어치(학명: Cyanocitta cristata) 또는 블루 제이(영어: blue jay)는 북아메리카에 서식하는 까마귀과의 철새이다. 미국 중동부 대부분의 지역에서 서식하며, 서부 개체들은 이주를 할 수 있다.
영어명인 블루 제이는 시끄럽고 수다스러운 본성 때문에 지어졌다. 영어권에서는 종종 "제이버드"(jaybird)라고도 부른다.
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