The robust cottontail or Holzner's cottontail (''Sylvilagus holzneri'') is a species of

cottontail Cottontail rabbits are the leporid species in the genus ''Sylvilagus'', found in the Americas. Most ''Sylvilagus'' species have stub tails with white undersides that show when they retreat, giving them their characteristic name. However, this ...

rabbit native to high-altitude regions of the southwestern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and western

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Taxonomy

This species and the subspecies comprising it were long considered to be subspecies of the

eastern cottontail The eastern cottontail (''Sylvilagus floridanus'') is a New World cottontail rabbit, a member of the family Leporidae. It is the most common rabbit species in North America. Distribution The eastern cottontail can be found in meadows and shrubb ...

(''S. floridanus''), but were promoted to species level due to morphological analysis. Genetic data have confirmed the uniqueness of ''S. holzneri''. ''S. holzneri'' and ''S. floridanus'' are distinguished primarily by size, dental, and cranial differences.

Subspecies

According to genetic analysis, there are three subspecies of ''S. holzneri'': * ''S. h. hesperius'': endemic to northwestern and central

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, from the

Hualapai Mountains The Hualapai Mountains are a mountain range located in Mohave County, east of Kingman, Arizona. Rising up to 8,417 feet at its highest peak, the higher elevations of the Hualapai Mountains support Madrean Sky Island habitats, and are host to ...

south to the

Sierra Ancha The Sierra Ancha ("broad range" in Spanish, in Western Apache: Dził Nteel - "Wide Flat Mountain") is a mountain range in Gila County, in central Arizona. It lies between Roosevelt Lake to the south, the Tonto Basin to the west, Cherry Creek t ...

. *''S. h. holzneri'': The most widespread subspecies, ranging throughout mountains from southeastern Arizona and south-central

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

(aside from the

Guadalupe Mountains The Guadalupe Mountains ( es, Sierra de Guadalupe) are a mountain range located in West Texas and southeastern New Mexico. The range includes the highest summit in Texas, Guadalupe Peak, , and the "signature peak" of West Texas, El Capitan, both ...

) south through

along the

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...

to Sinaloa. *''S. h. robustus'' or Davis Mountains cottontail: historically, this subspecies was known to be

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to four mountain ranges. In

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

, it was known in the

Davis Mountains The Davis Mountains, originally known as Limpia Mountains, are a range of mountains in West Texas, located near Fort Davis, after which they are named. The fort was named for then United States Secretary of War and later Confederate President J ...

and

Chisos Mountains The Chisos Mountains, also known as the Chisos, are a mountain range located in the Big Bend area of the Trans-Pecos region of Texas, United States. The mountain system covers 40 square miles (104 square km) and is contained entirely within the ...

. In New Mexico it was also known from the Guadalupe Mountains. In Coahuila, Mexico, it is known from the Sierra Madre Oriental mountain range. The Chisos and Guadalupe Mountains populations are suspected to be

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

. It is considered Vulnerable on the IUCN Red List. 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''.

"Manzano Mountain cottontail"

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 The Manzano Mountains are a small mountain range in the central part of the US State of New Mexico. They are oriented north–south and are 30 miles long. The center of the range lies due east of the town of Belen. The name "Manzano" is Spani ...

in New Mexico, where it occurs in

coniferous forests Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All exta ...

in high elevation, and was classified as

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

by the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

. 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.

Description

''S. holzneri'' typically averages a total length of 42 cm, and weighs between 1.3 and 1.8 kg. It is restricted to dry, brushy, mountains at elevations above 1500 meters.The mammals of Texas: 2nd edition
By David J. Schmidly, William B. Davis. 2004. pp. 466-467. University of Texas Press.

Conservation

Despite the rarity of ''S. h. robustus'', currently no governmental agency provides protection or listing for this subspecies.

References

{{Taxonbar, from=Q194815 Robust Cottontail Mammals of the United States Mammals of Mexico Mammals described in 1896 Taxa named by Edgar Alexander Mearns Taxobox binomials not recognized by IUCN Fauna of the Sierra Madre Occidental Fauna of the Sierra Madre Oriental