Sylvilagus graysoni (J. A. Allen, 1877)

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 : 122-123

24.

Tres Marias Cottontail

Sylvilagus graysoni

French: Lapin des Marias / German: Tres-Marias-Baumwollschwanzkaninchen / Spanish: Conejo de Tres Marias

Other common names: Tres Marias Rabbit

Taxonomy. Lepus graysoni]. A. Allen, 1877,

“Tres Marias Islands.” Restricted by E. W. Nelson in 1899 to “undoubtedly from Maria Madre [Island],” Nayarit, Mexico.

Existence of two subspecies of S. graysoni is under consideration (grayson: and badistes). Taxonomic, morphological, karyological, and biogeographical evidence support the view that insular S. grayson : shared a common mainland ancestor with S. cunicularius that invaded islands when they were very likely connected to the mainland during maximal Pleistocene glaciation. Monotypic.

Distribution. Islas Marias, Nayarit State (W Mexico).

Descriptive notes. Head-body 440-470 mm, tail 33-50 mm, ear 62-64 mm, hindfoot 91-95 mm. No specific data are available for body weight. The Tres Marias Cottontail is medium-sized, with relatively short ears. Dorsal fur is reddish and brightest on nape and rump;lateral fur is paler reddish. Ventral fur is whitish, except for brownish throat patch.

Habitat. Dense stands ofcacti, trees, brushes, and agaves 3-4 m high; tropical deciduous forests 4 m high; open woodland in coastal areas; agricultural coastal areas; and abandoned agricultural fields consisting of scattered growth of bushes from sea level to elevations of ¢.350 m. Insular habitats of the Tres Marias Cottontail are more arid than on the mainland. Average yearly rainfall is 635 mm; most of it falls during violet summer storms from the south-east. Temperatures are moderate, with monthly averages ranging from 20-3°C in January/February to 28-1°C in July/August.

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

Breeding. One study revealed that eleven female Tres Marias Cottontails were lactating and two females were pregnant in March.

Activity patterns. After 15:00 h, Tres Marias Cottontails have been seen sitting in small open places in the woods’ undergrowth, apparently waiting for sunset.

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 Tres Marias Cottontail is listed as critically endangered in Mexico. Its distribution in Mexico is limited to the Tres Marias Islands, an area less than 500 km2. These islands are located c.86 km off the western coast of Mexico (21-22° N, 106-107° W) and include four islands: Maria Madre, Maria Magdalena, Maria Cleofas, and San Juanito. Populations of Tres Marias Cottontails are declining because of extensive habitat alterations on these islands. In 1897, the Tres Marias Cottontail was abundant in some places on the four islands. During a 1987 expedition,it was found only on San Juanito Island, which makes up ¢.12% ofthe total possible extent of occurrence. Main threats are hunting; extensive clearing of habitats and introduced White-tailed Deer (Odocoileus virginianus), domestic pigs, and domestic goats; and increasing human settlements associated with a federal prison on Maria Madre Island. Populations of Tres Marias Cottontails were more abundant on the uninhabited islands of Maria Cleofas and San Juanito, but Maria Cleofas Island has been stripped of ¢.50% ofits native vegetation for human settlements. Recommendations to ensure survival of the Tres Marias Cottontails are to establish reserves on Maria Madre Island, turn San Juanito Island into an ecological reserve, and stop all hunting. Status surveys need to be conducted to determine population status and specific habitat requirements, and long-term research on natural history and population densities in long-term projects should be initiated. Maria Magdalena Island has been designated an ecological reserve by the Mexican government.

Bibliography. AMCELA, Romero & Rangel (2008e), Cervantes (1997), Chapman & Ceballos (1990), Chapman etal. (1990), Cervantes (1997), Diersing & Wilson (1980), Hall (1981), Hoffmann & Smith (2005), Lorenzo (1987), Nelson (1899a, 1909), Wilson (1991).

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. Islas Marias, Nayarit State (W Mexico).