Robust cottontails are strictly herbivorous, as are other cottontails. However, the specific plants eaten vary substantially among species depending on local availability. Cottontails feed on a variety of grasses and forbs but, when such vegetation is scarce during the winter, they eat the twigs and bark of shrubs and small trees. Coprophagy, or the reingestion of fecal pellets, has been documented for many species, although it has not been investigated closely in S. robustus. It is likely that soft, so-called “green food” pellets are ingested by S. robustus before they are even dropped, as 60% of these pellets are composed of useful nutrients.
Plant Foods: leaves; wood, bark, or stems; flowers
Other Foods: dung
Primary Diet: herbivore (Folivore , Lignivore); coprophage
Sylvilagus robustus is listed as Endangered on IUCN’s Red List, though the population trend is unknown. Other organizations do not list robust cottontails as endangered, likely because of its recent recognition as a distinct species. Because of this recent change, little is known about population trends.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Little specific information on communication and perception in robust cottontails is available. Mating communication is primarily based on scent and visual displays by males who compete over female mates. Sound plays a less important role in communication for most cottontails than does scent. Scents are secreted from special glands under the chin and in the groin area. Though rarely vocal, cottontails are capable of uttering high pitched squealing noises as a warning when attacked by a predator and they may drum their rear feet loudly as a warning.
Communication Channels: acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Taxonomic history in this group is complicated and contested. Sylvilagus robustus was first described as a distinct species by Nelson in 1909 on the basis of morphological features and lack of apparent intergrades, but was relegated to a subspecies of S. floridanus by Hall and Kelson on the basis of apparent morphological intermediacy of a single specimen. In 1974, Davis’s Mammals of Texas listed S. robustus as a separate species. It was again described as a subspecies by Schmidly (1977) in his Mammals of the Trans-Pecos after his examination of the widely varied S. floridanus throughout Texas and New Mexico, noting the “considerable overlap in external and cranial measurements among examples of S. robustus and S. floridanus specimens” (Vestal, 2005: 3) and the subspecific level differences within S. robustus. In 1994, Schmidly and Davis again updated the classification, noting classes of nominal cranial differences between S. floridanus and S. robustus, which were confirmed by a morphological analysis of 26 cranial, mandibular, and dental characters in 5 taxa of cottontails (Ruedas, 1998). Since that time, S. robustus has been recognized as a distinct species, although a 2005 study by Vestal suggested that subspecific genetic variation in cytochrome b exceeds interspecies divergence between S. robustus and S. f. cognatus. In response and explanation to this study, Lee et al. (2010) amplified fragment length polymorphisms using DNA fingerprinting techniques, which showed that there was a lack of gene flow between the two species and that this, combined with morphological data, should be enough to classify S. robustus as a distinct species.
Robust cottontails have caused minor damage to orchard trees in winter and gardens or other agriculturally important crops in summer. Contrary to their close relative, S. floridanus, robust cottontails are not commonly found in residential areas.
Negative Impacts: crop pest
Robust cottontails are sometimes hunted as game. Although other cottontail species reproduce rapidly, robust cottontail populations may not survive hunting pressure well because of their limited range.
Positive Impacts: food ; body parts are source of valuable material
Robust cottontails play an important role as a food source for their predators, a relationship which has been proposed to keep their populations cyclic and cause them to peak approximately once every ten years. In addition, they play an important role as hosts to a range of parasites, most importantly ticks, a vector for Rickettsia rickettsii. Specific information on parasites of robust cottontails is not available. Other Sylvilagus species are host to a range of ectoparasites, including ticks of the Ixodidae family, fleas of the Pulicidae and Leptopsyllidae families, and warbles of the family Cuterebridae. Endoparasites include the nematodes Obeliscoides, Trichostrongylus, Longistriata, and Trichuris, and the cestodes Mosgovoyia and Taenia.
Commensal/Parasitic Species:
Robust cottontails, or Davis Mountain cottontails, occupy mountainous areas in the southern United States and northern Mexico. They are found in the Trans-Pecos region between the Rio Grande River in New Mexico and the East Pecos River in Texas. This region is highly mountainous, containing the Guadalupe, Davis, Chinati, and Chisos Mountain Ranges, which are home to this species. It was previously thought that they had been extirpated from the Chisos Mountains, but populations have been found there between 2007 and 2012 in Big Bend National Park. Some populations are found in the Coahuila Range in Mexico, south of what was once considered their geographic distribution.
Biogeographic Regions: nearctic (Native )
Robust cottontails inhabit pinyon-oak-juniper woodland areas in mountain ranges at elevations mostly between 4700 and 8000 feet, though sometimes also at lower elevations. These areas tend to be dry, brushy mountain areas, and these rabbits inhabit dense brush of sumac or mahogany, emerging only toward evening to feed.
Range elevation: 460 to 2440 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: scrub forest ; mountains
Robust cottontails live up to 3 years in the wild but have been recorded living up to 8 years in captivity. Predation is the main limit to lifespan of robust cottontails in the wild.
Range lifespan
Status: wild: 3 (high) years.
Range lifespan
Status: captivity: 8 (high) years.
Robust cottontails are larger than their closest sister species, eastern cottontails. This light gray species of cottontail has large ears and light gray fur on the dorsal portion of its body with darker iron gray rump and black washing. The tail and underparts are white, the shoulders and top of the tail are brownish, and the abdomen is gray. They have several typical features shared by all species of Sylvilagus: large feet and ears, skulls containing a highly fenestrated maxillary bone, as well as supraorbital processes on the frontal bone, and straight cutting edges on the incisors with peglike teeth behind. The dental formula is 2/1, 0/0, 3/2, 3/3. The feet are particularly thickly furred. Cranial morphometrics most distinctly separate S. robustus from its closest relative, S. floridanus. These distinguishing features include: S. robustus possesses 2 distinct mandibular foramina of different size and conformation than S. floridanus; different shape of the interparietal and alisphenoid bones; lack of a tympanic process in S. robustus; mental foramena twice as long and located on the dorsal aspect of the mandible in S. robustus, while foramena on S. floridanus are less than one half as long and high and usually located on the labial aspect of the mandible.
Range mass: 1.3 to 1.8 kg.
Average length: 416 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
Robust cottontails experience predation by a number of mammalian and avian predators. In general, cottontail species behavioral responses to predation are well documented. They use dense cover to hide from predators and are active in open areas mostly at night. Cottontails also remain still and quiet when under threat by a predator in order to evade detection and are cryptically colored. Little is known about specific predators species of robust cottontails, but they may be preyed on by gray foxes (Urocyon cinereoargenteus), bobcats (Lynx rufus), golden eagles (Aquila chrysaetos), and great horned owls (Bubo virginianus), all of which are found in their range.
Known Predators:
Anti-predator Adaptations: cryptic
The mating system of robust cottontails has not been extensively studied, but it is thought that mating behaviors are similar to other Sylvilagus species. Breeding occurs at higher elevations than eastern cottontails, so may begin later on average. In almost all Sylvilagus species, aggressive male hierarchy systems exist where dominant males are able to obtain more mating opportunities. Dominance is maintained through aggressive interactions among males. Courting behaviors occur among members of Sylvilagus species, including defensive displays mainly at night. There is little additional information available on mating behavior in robust cottontails. Breeding among Sylvilagus species is promiscuous, with males and females each having multiple partners.
Mating System: polygynandrous (promiscuous)
Sylvilagus females can produce several litters per year. Like other lagomorphs, they exhibit induced ovulation, in which ovulation does not occur until copulation, causing breeding synchrony. Young are altricial and born in a nest. The number of young per litter varies according to time of year and corresponding temperature, rainfall, and food availability in the habitat and age of the female. In the range of robust cottontails, mean litter sizes of 4 have been reported. A female's first litter size generally ranges from 2.95 to 5.10. Mean litter size in eastern cottontails, the closest sister species, varies from 3.60 to 5.60. Females can produce up to 5 litters per year.
Gestation length information for robust cottontails are not available. However, a strong correlation between latitude and gestation length has been reported for all Sylvilagus species. Populations in southern areas have longer gestation periods while populations in northern areas have shorter gestation periods to support more litters in a shorter period of warm weather. The average gestation period for S. floridanus is 28 days, with a range of 25 to 35 days.
Sexual maturity for both males and females occurs at one year of age. However, juvenile females (under 1 year of age) may participate in breeding in their first summer. Most Sylvilagus young reach reproductive maturity after one year and participate in second year breeding. Some juvenile male reproductive activity has been reported (under 1 year of age), but has been presumed insignificant due to the polygamous breeding pattern of Sylvilagus. More young males may participate in late season breeding during their first year, as decreased libido has been observed among more senior males late in the season in many species of Sylvilagus.
Neonates of eastern cottontails weigh between 35 and 45 grams upon birth. The young open their eyes between day 6 and 7 and weaning is complete by day 15, with the young beginning to venture out of the nest by day 12.
Breeding interval: Females breed up to 5 times per year.
Breeding season: Because they breed at higher elevations, the breeding season of robust cottontails in most populations lasts all year.
Range number of offspring: 3.60 to 5.60.
Average number of offspring: 4.00.
Range gestation period: 25 to 35 days.
Average gestation period: 28 days.
Average weaning age: 15 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; viviparous
Female robust cottontails are primarily responsible for caring for the young. Before the litter is born, the mother builds a nest, a slanting hole in the ground in a protected area, and lines it with leaves and a layer of her own fur. In Texas, five of these nests averaged 12.5 cm in length, 10.4 cm in width, and 9.1 cm in depth (Bothma and Teer, 1977). Young are born naked, blind, and therefore entirely dependent on their mothers. Mothers care for their young until they are able to leave the nest.
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Ar c'honikl postek (Sylvilagus robustus) a zo ur bronneg geotdebrer a vev er Stadoù-Unanet ha Mec'hiko.
Sylvilagus robustus és una espècie de conill del gènere Sylvilagus. Alguns autors la consideren una subespècie de S. floridanus (el conill de Florida). Viu al sud dels Estats Units i el nord de Mèxic.
Das Texas-Baumwollschwanzkaninchen (Sylvilagus robustus) ist eine Säugetierart aus der Gattung der Baumwollschwanzkaninchen innerhalb der Hasenartigen. Sein Verbreitungsgebiet umfasste ursprünglich einzelne Gebirgszüge in New Mexico, Texas und im Bundesstaat Coahuila, Mexiko. Das heutige Verbreitungsgebiet ist jedoch wahrscheinlich auf die Davis Mountains in Texas beschränkt, während die Art in den anderen Regionen wohl ausgestorben ist. Die verbliebenen Bestände reagieren offenbar sehr empfindlich auf Trockenheit, zudem bestehen weitere Gefährdungen durch Lebensraumzerstörung. Das Texas-Baumwollschwanzkaninchen wird von der International Union for Conservation of Nature and Natural Resources (IUCN) als stark gefährdet (endangered) eingestuft.
Das Texas-Baumwollschwanzkaninchen entspricht in Größe und Aussehen dem Florida-Waldkaninchen (Sylvilagus floridanus), als dessen Unterart es ursprünglich betrachtet wurde. Es ist eine mittelgroße Art seiner Gattung mit einer Kopf-Rumpf-Länge von 37,5 bis 46,3 Zentimeter.[1] Vom Florida-Waldkaninchen lässt es sich eindeutig nur durch verschiedene Schädelmaße und Merkmale der Zähne unterscheiden.[2]
Ursprünglich war das Texas-Baumwollschwanzkaninchen in den Guadalupe Mountains in Texas und New Mexico, den Chisos Mountains und den Davis Mountains in Texas und der Sierra de la Madera im Bundesstaat Coahuila, Mexiko, anzutreffen. In den Guadalupe Mountains, den Chisos Mountains und in Mexiko gilt die Art heute als ausgestorben, Das Texas-Baumwollschwanzkaninchen kommt heute wahrscheinlich nur noch in den Davis Mountains in Texas vor. Ein Vorkommen von Baumwollschwanzkaninchen soll es in der Sierra del Carmen in Mexiko geben, dabei ist jedoch unklar, um welche Art es sich handelt.[1] 2012 berichteten Nalls et al. allerdings, dass sie Individuen der Art in den Chisos Mountains gesammelt und identifiziert haben und damit außer in den Davis Mountains noch ein zweites Vorkommen existiert.[3]
Die Höhenverbreitung des Texas-Baumwollschwanzkaninchens kommt soweit bekannt nur oberhalb von 1.500 Metern und wird erst über 1.800 Metern häufiger. Bei ausschließlicher Berücksichtigung von Höhenlagen oberhalb 1.675 Meter beträgt die zur Verfügung stehende Fläche mit der von der Art bevorzugten Vegetation in den Davis Mountains etwa 730 Quadratkilometer.[1]
Über die Lebensweise des Texas-Baumwollschwanzkaninchens liegen nur sehr wenige Informationen vor. Sein Lebensraum sind die Madrean Pine-Oak Woodlands, subtropische und immergrüne Waldgebiete. Es wird angenommen, dass seine Lebensweise der des Florida-Waldkaninchens sehr ähnlich ist.[1]
Das Texas-Baumwollschwanzkaninchen wird als eigenständige Art den Baumwollschwanzkaninchen (Gattung Sylvilagus) zugeordnet. Ursprünglich galt es als Unterart des Florida-Waldkaninchens (Sylvilagus floridanus).[4][5] Ruedas 1998 konnte durch morphologische Vergleiche des Schädels und der Zähne verschiedener Unterarten des Florida-Waldkaninchens nachweisen, dass S. robustus ebenso wie Sylvilagus cognatus eigenständige Arten der Gattung sind.[2] 2010 bestätigten Lee et al. die Eigenständigkeit der Art durch molekularbiologische Untersuchungen.[6]
Innerhalb der Art werden keine Unterarten unterschieden.[5]
Das Texas-Baumwollschwanzkaninchen wird von der International Union for Conservation of Nature and Natural Resources (IUCN) als „stark gefährdet“ (endangered) eingestuft.[1] Ursprünglich ist die Art von mehreren Höhenzügen bekannt, heute lebt sie wahrscheinlich nur noch in den Davis Mountains und ist in den anderen Regionen ausgestorben und seit den 1960er Jahren wurden keine lebenden Individuen in diesen Gebieten nachgewiesen. In den 1970er Jahren erfolgten zwei unbestätigte Sichtungen in den Guadalupe Mountains. Der letzte Nachweis aus den Davis Mountains, ein auf einer Straße getötetes Tier, stammt von 1997 und war der erste Nachweis nach 20 Jahren.[2][1]
Die Gesamtfläche des verbliebenen Verbreitungsgebietes in den Davis Mountains beträgt nur etwa 1.815 Quadratkilometer, wobei das für die Kaninchen nutzbare Gebiet wohl nur etwa 730 Quadratkilometer groß ist.[2][1] Aufgrund von Dürren und anderen Einflüssen kommt es zu großen Fluktuationen der Individuenzahlen und der Anzahl fortpflanzungsfähiger Kaninchen.[1]
Die Hauptbedrohung für die Art geht vor allem von ihrer sehr geringen Individuenzahl und -dichte aus, die sie sehr empfindlich gegenüber Dürren und andere Einflüsse macht. Zugleich nimmt der Lebensraum durch Lebensraumzerstörungen infolge von Urbanisierung und der Ausweitung von Weideflächen ab.[2][1]
Das Texas-Baumwollschwanzkaninchen (Sylvilagus robustus) ist eine Säugetierart aus der Gattung der Baumwollschwanzkaninchen innerhalb der Hasenartigen. Sein Verbreitungsgebiet umfasste ursprünglich einzelne Gebirgszüge in New Mexico, Texas und im Bundesstaat Coahuila, Mexiko. Das heutige Verbreitungsgebiet ist jedoch wahrscheinlich auf die Davis Mountains in Texas beschränkt, während die Art in den anderen Regionen wohl ausgestorben ist. Die verbliebenen Bestände reagieren offenbar sehr empfindlich auf Trockenheit, zudem bestehen weitere Gefährdungen durch Lebensraumzerstörung. Das Texas-Baumwollschwanzkaninchen wird von der International Union for Conservation of Nature and Natural Resources (IUCN) als stark gefährdet (endangered) eingestuft.
Il-Fenek ta' denbu qotni tal-muntanji ta' Davis jew Denb qotni tal-muntanji ta' Davis jew Fenek robust, li hu magħruf xjentifikament bħala Sylvilagus robustus huwa mammiferu plaċentat tad-Dinja l-Ġdida u membru tal-familja Leporidae (leporidu), fl-ordni Lagomorpha (lagomorfu). Dan id-denb qotni huwa nattiv tal-kontinent ta' l-Amerika ta' fuq, endemiku tal-iStati Uniti.
Dan id-denb qotni huwa simili ħafna tal-Fenek ta' denbu qotni tal-Lvant Sylvilagus floridanus u diffiċli ħafna biex jingħarfu minn xulxin. Il-Fenek ta' denbu qotni tal-muntanji ta' Davis Sylvilagus robustus żmien ilu kien meqjus bħala sottospeċi tal-Fenek ta' denbu qotni tal-Lvant.
Il-Fenek ta' denbu qotni tal-muntanji ta' Davis huwa speċi ta' denb qotni li hija ristretta u għandha distribuzzjoni fuq il-muntanji Davis biss, endemiku tal-istat tat-Texas, fl-iStati Uniti f' arja mhux protetta bejn Guadalupe u l-Park Nazjonali ta' Big Bend.
Dan il-fenek huwa 1 minn 9 speċi ta' dnieb qotna, li qegħdin klassifikati fis-sottoġeneru Sylvilagus u m' hemmx sottospeċi rikonoxxuti.
"Sylvilagus floridanus robustus" huwa sinonimu jew l-istess bħal u jirreferi għal Sylvilagus robustus ta' Bailey, 1905.
Il-Fenek ta' denbu qotni tal-muntanji ta' Davis jew Denb qotni tal-muntanji ta' Davis jew Fenek robust, li hu magħruf xjentifikament bħala Sylvilagus robustus huwa mammiferu plaċentat tad-Dinja l-Ġdida u membru tal-familja Leporidae (leporidu), fl-ordni Lagomorpha (lagomorfu). Dan id-denb qotni huwa nattiv tal-kontinent ta' l-Amerika ta' fuq, endemiku tal-iStati Uniti.
Dan id-denb qotni huwa simili ħafna tal-Fenek ta' denbu qotni tal-Lvant Sylvilagus floridanus u diffiċli ħafna biex jingħarfu minn xulxin. Il-Fenek ta' denbu qotni tal-muntanji ta' Davis Sylvilagus robustus żmien ilu kien meqjus bħala sottospeċi tal-Fenek ta' denbu qotni tal-Lvant.
The robust cottontail or Holzner's cottontail (Sylvilagus holzneri) is a species of cottontail rabbit native to high-altitude regions of the southwestern United States and western Mexico.[2]
This species and the subspecies comprising it were long considered to be subspecies of the eastern cottontail (S. floridanus), but were promoted to species level due to morphological analysis.[3][4] Genetic data have confirmed the uniqueness of S. holzneri.[5] S. holzneri and S. floridanus are distinguished primarily by size, dental, and cranial differences.
According to genetic analysis, there are three subspecies of S. holzneri:[3]
All three of these were previously considered subspecies of S. floridanus. One (robustus) was already resurrected as a distinct species in 1998, and was considered as such until being reclassified as a subspecies of the newly-resurrected holzneri in 2021, with the common name "robust cottontail" carrying over to holzneri.[2][6]
The Manzano Mountain cottontail (S. cognatus) was a species of Sylvilagus also previously classified in S. floridanus, until it was later reclassified as a distinct species. This species was thought to be restricted to the Manzano Mountains in New Mexico, where it occurs in coniferous forests in high elevation, and was classified as Endangered by the IUCN Red List. However, a 2021 phylogenetic analysis found S. cognatus to be indistinguishable from S. h. holzneri and synonymized it with holzneri. This classification was followed by the American Society of Mammalogists.[3][2]
S. holzneri typically averages a total length of 42 cm, and weighs between 1.3 and 1.8 kg.[7] It is restricted to dry, brushy, mountains at elevations above 1500 meters.[7]
Despite the rarity of S. h. robustus, currently no governmental agency provides protection or listing for this subspecies.[1]
{{cite journal}}: CS1 maint: multiple names: authors list (link) The robust cottontail or Holzner's cottontail (Sylvilagus holzneri) is a species of cottontail rabbit native to high-altitude regions of the southwestern United States and western Mexico.
Sylvilagus robustus Sylvilagus generoko animalia da. Lagomorpharen barruko Leporidae familian sailkatuta dago.
Sylvilagus robustus Sylvilagus generoko animalia da. Lagomorpharen barruko Leporidae familian sailkatuta dago.
Sylvilagus robustus est une espèce de lapins de la famille des Léporidés endémique des États-Unis.
Il silvilago robusto (Sylvilagus robustus Bailey, 1905) è una rara specie di silvilago endemica del Sud-ovest americano.
Ritenuto in passato una sottospecie del silvilago orientale, questo coniglio è lungo 37,5-46,3 cm.
È diffuso soltanto sui monti Chisos, Davis e Guadalupe, in Texas e Nuovo Messico, e sulla Sierra de la Madera, nell'adiacente stato messicano di Coahuila. Forse ne sopravvive qualcuno anche sulla Sierra del Carmen.[1][2]
La Lista rossa IUCN classifica Sylvilagus robustus come specie vulnerabile.[2] Questa specie, ritenuta già rara di natura, ha subito nel corso del XX secolo una continua diminuzione. Negli anni quaranta ne rimanevano solo 50 esemplari sui Monti Guadalupe, ma, a parte due individui avvistati negli anni settanta, dagli anni sessanta quella popolazione è ritenuta scomparsa. L'ultimo esemplare noto che viveva sui Monti Davis fu un individuo investito da un'auto nel 1997. Sulla Sierra de la Madera ne sopravvive forse una popolazione in buone condizioni, sempre che non si tratti di una popolazione di silvilaghi orientali, anch'essi presenti nella zona e molto simili al silvilago robusto.
Il silvilago robusto (Sylvilagus robustus Bailey, 1905) è una rara specie di silvilago endemica del Sud-ovest americano.
Arnab Ekor Kapas Pergunungan Davis (Sylvilagus robustus) merupakan satu spesies arnab ekor kapas yang endemik di empat banjaran gunung di rantau barat daya Amerika Syarikat dan kawasan Mexico yang bersebelahan. Selama ini, ia pernah dikira sebagai subspesies Arnab Ekor Kapas Timur (S. floridanus), tetapi baru-baru ini telah dinaikkan ke taraf spesies setelah menjalani analisa morfologi.[2] S. robustus dibezakan daripada subspesies-subspesies S. floridanus terutamanya kerana perbezaan saiz, kegigian dan kraniumnya. Arnab ini biasanya mencapai purata kepanjangan tubuh 42 cm, dan beratnya antara 1.3 dan 1.8 kg.[3] Taburan spesies ini terhad kepada kawasan pergunungan yang kering dan bersemak di atas paras 1500 meter.[3] Sungguhpun jarang ditemui, namun spesies ini tidak menerima apa-apa perlindungan atau penyenaraian agensi kerajaan buat masa ini.[1]
Dahulunya, spesies ini dikenali sebagai endemik di empat banjaran gunung. Di negeri Texas, ia dikenali dari banjaran-banjaran Guadalupe, Davis dan Chisos. Di New Mexico, ia dikenali dari Pergunungan Guadalupe. Di negeri Coahuila, Mexico, arnab ini dikenali dari Sierra de la Madera. Arnab ini dipercayai sudah pupus dari banjaran Chisos dan Guadalupe.[1]
Arnab Ekor Kapas Pergunungan Davis (Sylvilagus robustus) merupakan satu spesies arnab ekor kapas yang endemik di empat banjaran gunung di rantau barat daya Amerika Syarikat dan kawasan Mexico yang bersebelahan. Selama ini, ia pernah dikira sebagai subspesies Arnab Ekor Kapas Timur (S. floridanus), tetapi baru-baru ini telah dinaikkan ke taraf spesies setelah menjalani analisa morfologi. S. robustus dibezakan daripada subspesies-subspesies S. floridanus terutamanya kerana perbezaan saiz, kegigian dan kraniumnya. Arnab ini biasanya mencapai purata kepanjangan tubuh 42 cm, dan beratnya antara 1.3 dan 1.8 kg. Taburan spesies ini terhad kepada kawasan pergunungan yang kering dan bersemak di atas paras 1500 meter. Sungguhpun jarang ditemui, namun spesies ini tidak menerima apa-apa perlindungan atau penyenaraian agensi kerajaan buat masa ini.
Sylvilagus robustus is een zoogdier uit de familie van de hazen en konijnen (Leporidae). De wetenschappelijke naam van de soort werd voor het eerst geldig gepubliceerd door Bailey in 1905.
Bronnen, noten en/of referenties
O Sylvilagus robustus é um leporídeo norte-americano, que até então era considerado uma subespécie do Sylvilagus floridanus. É encontrado nos estados do Texas e Novo México, nos Estados Unidos da América, e em Coahuila, no México.
O Sylvilagus robustus é um leporídeo norte-americano, que até então era considerado uma subespécie do Sylvilagus floridanus. É encontrado nos estados do Texas e Novo México, nos Estados Unidos da América, e em Coahuila, no México.
Sylvilagus robustus[3][4] är en däggdjursart som först beskrevs av Bailey 1905. Sylvilagus robustus ingår i släktet bomullssvanskaniner, och familjen harar och kaniner.[5][6] IUCN kategoriserar arten globalt som starkt hotad.[1] Inga underarter finns listade i Catalogue of Life.[5]
Arten förekommer i en bergstrakt i gränsområdet mellan Mexiko och USA (Texas). Den vistas i regioner som ligger minst 1500 meter över havet. Sylvilagus robustus lever i landskap med städsegröna buskar eller träd. Den blir 37,5 till 46,3 cm lång (huvud och bål). Arten har troligen samma levnadssätt som Sylvilagus floridanus.[1]
Denna bomullssvanskanin väger 745 till 1200 g, har cirka 103 mm långa bakfötter och 87 till 104 mm långa öron. Tandformeln är I 2/1 C 0/0 P 3/2 M 3/3, alltså 28 tänder.[7]
Wikimedia Commons har media som rör Sylvilagus robustus.
Wikispecies har information om Sylvilagus robustus.
Sylvilagus robustus är en däggdjursart som först beskrevs av Bailey 1905. Sylvilagus robustus ingår i släktet bomullssvanskaniner, och familjen harar och kaniner. IUCN kategoriserar arten globalt som starkt hotad. Inga underarter finns listade i Catalogue of Life.
Arten förekommer i en bergstrakt i gränsområdet mellan Mexiko och USA (Texas). Den vistas i regioner som ligger minst 1500 meter över havet. Sylvilagus robustus lever i landskap med städsegröna buskar eller träd. Den blir 37,5 till 46,3 cm lång (huvud och bål). Arten har troligen samma levnadssätt som Sylvilagus floridanus.
Denna bomullssvanskanin väger 745 till 1200 g, har cirka 103 mm långa bakfötter och 87 till 104 mm långa öron. Tandformeln är I 2/1 C 0/0 P 3/2 M 3/3, alltså 28 tänder.
Sylvilagus robustus là một loài động vật có vú trong họ Leporidae, bộ Thỏ. Loài này được Bailey mô tả năm 1905.[2]
Phương tiện liên quan tới Sylvilagus robustus tại Wikimedia Commons
.png){kind=small}
Bài viết liên quan đến động vật có vú này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Sylvilagus robustus là một loài động vật có vú trong họ Leporidae, bộ Thỏ. Loài này được Bailey mô tả năm 1905.
Sylvilagus robustus Bailey, 1905
Ареал
Sylvilagus robustus — один из видов американских кроликов, эндемичный для четырёх горных хребтов на юго-западе США и в соседней Мексике[1].
На протяжении долгого времени считался подвидом флоридского кролика (S. floridanus), но недавно был повышен до уровня вида на основании результатов морфологического анализа[2]. Генетические данные подтвердили уникальность Sylvilagus robustus[3]. Sylvilagus robustus и различные подвиды S. floridanus различаются прежде всего по размерам, особенностям строения зубов и черепа.
Длина тела этого вида в среднем 42 см и вес от 1,3 до 1,8 кг[4]. Распространение этого вида ограничено сухими, поросшими кустарником горами на высотах более 1500 метров[4]. Несмотря на редкость Sylvilagus robustus, в настоящее время ни одно из правительственных учреждений не обеспечивает охрану или включение в краснокнижный список этого вида[5].
В историческое время этот вид был известен как эндемик четырёх горных хребтов. В Техасе он обитал в горах Гуадалупе-Маунтинс[en], горах Дэвис-Маунтинс[en] и горах Чисос-Маунтинс[en]. В штате Нью-Мексико был обнаружен в Гуадалупе-Маунтинс. И в мексиканском штате Коауила этот вид был известен из Сьерра-де-ла-Мадера[6]. Предполагают, что популяции в горах Чисос-Маунтинс и Гуадалупе-Маунтинс были истреблены[5].
Sylvilagus robustus — один из видов американских кроликов, эндемичный для четырёх горных хребтов на юго-западе США и в соседней Мексике.
데이비스산맥토끼(Sylvilagus robustus)는 토끼과에 속하는 포유류의 일종이다. 미국 남서부의 4개 산악 지역과 인접한 멕시코 지역에서 발견된다. 오랫동안 동부솜꼬리토끼의 아종으로 간주해 왔지만, 형태학적 분석을 통해 최근에는 별도의 종으로 승격하여 분류하고 있다.[2] 이는 유전 정보를 통해 확인되었다.[3] 데이비스산맥토끼(S. robustus)와 동부솜꼬리토끼(S. floridanus)의 아종은 주로 크기와 치아, 두개골에서 차이를 보인다. 전체 몸길이는 대략 평균적으로 42 cm, 몸무게는 1.3~1.8 kg 정도이다.[4] 이 종들은 건조하고, 덤불이 덮힌 1,500m 이상의 산악 지대에 제한적으로 서식한다.[4]
데이비스산맥토끼(Sylvilagus robustus)는 토끼과에 속하는 포유류의 일종이다. 미국 남서부의 4개 산악 지역과 인접한 멕시코 지역에서 발견된다. 오랫동안 동부솜꼬리토끼의 아종으로 간주해 왔지만, 형태학적 분석을 통해 최근에는 별도의 종으로 승격하여 분류하고 있다. 이는 유전 정보를 통해 확인되었다. 데이비스산맥토끼(S. robustus)와 동부솜꼬리토끼(S. floridanus)의 아종은 주로 크기와 치아, 두개골에서 차이를 보인다. 전체 몸길이는 대략 평균적으로 42 cm, 몸무게는 1.3~1.8 kg 정도이다. 이 종들은 건조하고, 덤불이 덮힌 1,500m 이상의 산악 지대에 제한적으로 서식한다.
