Sylvilagus insonus (Nelson, 1904)

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Leporidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 107-148 : 120

18.

Omilteme Cottontail

Sylvilagus insonus

French: Lapin d’'Omiltemi / German: Omilteme-Baumwollschwanzkaninchen / Spanish: Conejo de Omiltemi

Other common names: Omiltemi Cottontail, Omiltemi Rabbit

Taxonomy. Sylvilagus insonus Nelson, 1904 ,

“Omilteme, Guerrero,” Mexico.

Phylogenetic relationships of S. insonus to other species of Sylvilagus are unclear. Sylvilagus insonus and S. brasiliensis were considered to be more closely related to each other than to other species of Sylvilagus and were placed in the subgenus Tapeti. Later, S. insonus was transferred to the subgenus Sylvilagus because it did not appear to be a Tapeti. Finally, morphological comparisons between S. brasiliensis , S. dicer , and S. insonus using univariate and multivariate techniques indicated that S. brasiliensis and S. dicei are more closely related to each other than either is to S. insonus , and they supported placement of S. insonus in the subgenus Sylvilagus . This species lives sympatrically with S. cunicularius. Monotypic.

Distribution. Omiltemi State Ecological Park, Sierra Madre del Sur, C Guerrero (SW Mexico).

Descriptive notes. Head-body 430-500 mm, tail 40-45 mm, ear 60 mm, hindfoot 93-96 mm (all measurements from two individuals). No specific data are available for body weight but probably 500-950 g. The Omilteme Cottontail is large, with long ears. It has medium-sized hindfeet and short tail. Dorsal fur is rufous black, with dull dingy rusty-rufous nape. Ears are grizzled and dark blackish brown, with more black along anterior borders and attips. Sides are grayish black. Sides of nose and eye rings are dingy, grayish-buff. Tail is reddish black above. Ventral fur is whitish, with brownish throat patch. Tops of hindfeet are whitish. The Omilteme Cottontail is known only from two specimens available in the Smithsonian Institution’s National Museum of Natural History, so diagnostic information is limited and might not be accurate.

Habitat. Dense cloud forests of pine and pine—oak at elevations of 2133-5280 m. Dominant trees are pine ( Pinus , Pinaceae ), oak ( Quercus , Fagaceae ), fir ( Abies , Pinaceae ), and cypress ( Cupressus , Cupressaceae ) that might reach 40 m in height. Weather is humid most of the year, and most rainfall occurs during summer. The Omilteme Cottontail lives in dense undergrowth, makes runways, and occupies burrows under rocks or similar shelter.

Food and Feeding. There is no information available for this species.

Breeding. There is no information available for this species.

Activity patterns. There is no specific information available for this species, but the Omilteme Cottontail is mainly nocturnal.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. Classified as Endangered on The IUCN Red List. The Omilteme Cottontail is listed ascritically endangered in Mexico. It is rare, and its distribution includes less than 500 km?®. Much ofits known distribution occurs in Omiltemi State Ecological Park, a nature reserve of ¢.3613 ha. Nevertheless, major threats to survival of the Omilteme Cottontail are poaching and deforestation. Forests in the region have been intensively logged and used for cattle grazing, resulting in significant fragmentation and modification of the habitat. The Omilteme Cottontail had not been reported in the wild since the early 1900s, although a possible sighting was made in 1991. An inventory of mammals of Omiltemi State Ecological Park conducted in 1993 did not document the Omilteme Cottontail. Therefore, the Mexican government declared the Omiltemi Cottontail endangered in 1994. During a 1998 survey to clarify status of the Omilteme Cottontail, two specimen were killed for food by locals c.1 km south-south-east of the village of Omiltemi, and the dried skin of one specimen (without forefeet and hindfeet) was recovered. Genetic analysis, color pattern offur, and habitat where the specimen was obtained confirmed that it was an Omilteme Cottontail. Recommendations are to clarify present distribution and population status of the Omilteme Cottontail, enhance habitat conservation, enforce its protected status and stop hunting, and conduct research on its biology and ecology.

Bibliography. AMCELA, Romero & Rangel (2008b), Ceballos (2014), Ceballos & Navarro (1991), Cervantes & Lorenzo (1997), Cervantes et al. (2004), Chapman & Ceballos (1990), Diersing (1981), Hershkovitz (1950), Hoffmann & Smith (2005), Nelson (1904, 1909).

Figures

1. Amami Rabbit (Pentalagus furnessi), 2. Jameson’s Red Rock Hare (Pronolagus randensis), 3. Natal Red Rock Hare (Pronolagus crassicaudatus), 4. Smith’s Red Rock Hare (Pronolagus rupestris), 5. Hewitt’s Red Rock Hare (Pronolagus saundersiae), 6. Volcano Rabbit (Romerolagus diaz), 7. Riverine Rabbit (Bunolagus monticularis), 8. Pygmy Rabbit (Brachylagus idahoensis), 9. Sumatran Striped Rabbit (Nesolagus netscher), 10. Annamite Striped Rabbit (Nesolagus timminsi), 11. Brush Rabbit (Sylvilagus bachmani), 12. San Jose Brush Rabbit (Sylvilagus mansuetus), 13. Desert Cottontail (Sylvilagus audubonii), 14. Mountain Cottontail (Sylvilagus nuttallii), 15. New England Cottontail (Sylvilagus transitionalis)

Distribution. Omiltemi State Ecological Park, Sierra Madre del Sur, C Guerrero (SW Mexico).