Thomomys nayarensis Mathis et al. 2013

11. Nayar Pocket Gopher Thomomys nayarensis French: Gaufre de la Nayar / German: Nayarit-Taschenratte / Spanish: Tuza de Nayar Taxonomy. Thomomys nayarensis Mathis et al., 2013, “Mexico: Nayarit; 8.5 km N, 7 km W Mesa del Nayar, 2,200 m.” Placed into subgenus Megascapheus. Specimens of 1. nayarensis were formerly identified as T. umbrinus. Molecular studies show T. nayarensis to be a member of the T. umbrinus species group, which includes T. umbrinus, T. atrovarius, T. sheldoni, and T. nayarensis. Monotypic. Distribution. Known from only two localities in the Sierra del Nayar, NE Nayarit, Mexico. Descriptive notes. Head-body 110-140 mm, tail 50-75 mm, hindfoot 23-27 mm; weight 75-110 g. Male Nayar Pocket Gophers are slightly larger than females. This medium-sized pocket gopher has a fusiform body shape typical of all pocket gophers, and it possesses fur-lined cheek pouches that open external to the mouth. Its pelage is medium brown dorsally and golden-yellowish brown ventrally. All specimen of the Nayar Pocket Gopher known to date have few or no prominent guard hairs on dorsal rump, and these guard hairs, if present, extend no more than 3 mm beyond surrounding wool hairs. Female Nayar Pocket Gophers have three pairs of mammae, one pectoral and two inguinal. Chromosomal complement has 2n = 76 and FN = 146. Habitat. Open, grassy meadows in pine-oak woodlands and in nearby agricultural fields. Soils in these regions are typically deep and friable. Known elevational range of the Nayar Pocket Gopher is 1300-2200 m. Food and Feeding. There is no specific information available for this species, but all pocket gophers that have been studied eat predominately underground roots and tubers and a limited amount of surface vegetation. As in all other pocket gophers, the burrow system is a series of shallow feeding tunnels radiating spoke-like from a deeper, central network that contains one or more nest chambers and several smaller chambers for storage of food or fecal pellets. Breeding. There is no specific information available for this species, but male Nayar Pocket Gophers collected in January appeared to be in reproductive condition and females did not. Activity patterns. Limited observations suggest that the Nayar Pocket Gopheris active at any hour of the day, with periods of peak activity around dawn and dusk. It does not hibernate and is active year-round. Movements, Home range and Social organization. The Nayar Pocket Gopheris solitary and aggressively territorial. Because it rarely leaves its burrow system, its home range is defined by size and extent ofits burrow system. Field observations suggest that home range size is typical of that measured in other medium-sized pocket gophers, covering 30-80 m* of surface area. Status and Conservation. The Nayar Pocket Gopher has not been listed on The [UCN Red List. It may be vulnerable because of its extremely limited distribution. Bibliography. Mathis et al. (2013b), IUCN (20154).Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Geomyidae, pp. 234-269 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 240, DOI: 10.5281/zenodo.660380