Texas cottontail rabbit
| Texas cottontail rabbit | ||||||||||||
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| Sylvilagus robustus | ||||||||||||
| ( Bailey , 1905) |
The Texas-cottontail rabbit ( robust cottontail ) is a mammalian species in the genus of cottontail rabbit in the leporidae . Its distribution area originally comprised individual mountain ranges in New Mexico , Texas and in the state of Coahuila , Mexico . Today's range is likely limited to the Davis Mountains in Texas, while the species is believed to be extinct in the other regions. The remaining stands are evidently very sensitive to drought, and there are further threats from habitat destruction. The Texas cottontail rabbit is classified as endangered by the International Union for Conservation of Nature and Natural Resources (IUCN).
features
The Texas cottontail rabbit is similar in size and appearance to the Florida cottontail ( Sylvilagus floridanus ), the subspecies of which it was originally considered to be. It is a medium-sized species of its genus with a head-torso length of 37.5 to 46.3 centimeters. It can be clearly distinguished from the Florida cottontail only by different skull dimensions and features of the teeth.
distribution
Originally, the Texas cottontail rabbit was found in the Guadalupe Mountains in Texas and New Mexico, the Chisos Mountains and Davis Mountains in Texas, and the Sierra de la Madera in the state of Coahuila , Mexico . In the Guadalupe Mountains, the Chisos Mountains and in Mexico, the species is now considered extinct. The Texas cottontail rabbit is now likely only found in the Davis Mountains in Texas. Cottontail rabbits are said to be found in the Sierra del Carmen in Mexico, but it is unclear what species it is. In 2012, Nalls et al. however, that they have collected and identified individuals of the species in the Chisos Mountains and thus a second occurrence besides the Davis Mountains exists.
As far as is known, the height distribution of the Texas cottontail rabbit only occurs above 1,500 meters and only becomes more common above 1,800 meters. If altitudes above 1,675 meters are taken into account, the available area with the vegetation preferred by the species in the Davis Mountains is around 730 square kilometers.
Way of life
Very little information is available about the way of life of the Texas cottontail rabbit. Its habitat is the Madrean Pine-Oak Woodlands , subtropical and evergreen forest areas . Its lifestyle is believed to be very similar to that of the Florida forest rabbit.
Systematics
The Texas cottontail rabbit is assigned to the cottontail rabbit (genus Sylvilagus ) as an independent species . It was originally considered a subspecies of the Florida forest rabbit ( Sylvilagus floridanus ). Ruedas 1998 was able to demonstrate through morphological comparisons of the skull and the teeth of different subspecies of the Florida forest rabbit that S. robustus as well as Sylvilagus cognatus are independent species of the genus. In 2010, Lee et al. the independence of the species through molecular biological studies.
No subspecies are distinguished within the species.
Hazard and protection
The Texas cottontail rabbit is on the International Union for Conservation of Nature and Natural Resources ((IUCN) as "critically endangered" endangered ) classified. Originally the species is known from several mountain ranges, today it probably only lives in the Davis Mountains and is extinct in the other regions and no living individuals have been recorded in these areas since the 1960s. In the 1970s, there were two unconfirmed sightings in the Guadalupe Mountains. The last evidence from the Davis Mountains, an animal killed on a road, dates from 1997 and was the first evidence in 20 years.
The total area of the remaining distribution area in the Davis Mountains is only about 1,815 square kilometers, whereby the area usable for the rabbits is probably only about 730 square kilometers. Due to droughts and other influences, there are large fluctuations in the number of individuals and the number of reproductive rabbits.
The main threat to the species comes from its very low number and density of individuals, which makes it very sensitive to droughts and other influences. At the same time, the habitat is decreasing due to habitat destruction as a result of urbanization and the expansion of pasture areas.
supporting documents
- ↑ a b c d e f g h i Sylvilagus robustus in the IUCN Red List of Threatened Species 2012.2. Posted by: L. Ruedas, Andrew T. Smith , 2008. Retrieved November 26, 2012.
- ↑ a b c d e Luis A. Ruedas Systematics of Sylvilagus Gray, 1867 (Lagomorpha: Leporidae) from southwestern North America. Journal of Mammalogy 79 (4), 1998; Pp. 1355-1378. ( JSTOR )
- ↑ Amy V. Nalls, Loren K. Ammerman, Robert C. Dowler: Genetic and Morphologic Variation in the Davis Mountains Cottontail (Sylvilagus robustus). The Southwestern Naturalist 57 (1), 2012; Pp. 1-7. ( BioOne )
- ^ Joseph A. Chapman, Gerardo Ceballos: The Cottontails. In: Joseph A. Chapman, John EC Flux (Eds.): Rabbits, Hares and Pikas. Status Survey and Conservation Action Plan. (PDF; 11.3 MB) International Union for Conservation of Nature and Natural Resources (IUCN), Gland 1990; P. 106. ISBN 2-8317-0019-1 .
- ↑ a b Don E. Wilson & DeeAnn M. Reeder (eds.): Sylvilagus robustus in Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed).
- ^ Dana N. Lee, Russell S. Pfau, and Loren K. Ammerman: Taxonomic status of the Davis Mountains cottontail, Sylvilagus robustus, revealed by amplified fragment length polymorphism. Journal of Mammalogy 91 (6), 2010; Pp. 1473–1483 ( BioOne )
Web links
- Sylvilagus robustus inthe IUCN 2012 Red List of Threatened Species . 2. Posted by: L. Ruedas, Andrew T. Smith , 2008. Retrieved November 26, 2012.