Cratogeomys castanops

35. Yellow-faced Pocket Gopher Cratogeomys castanops French: Gaufre a face jaune / German: Gelbgesicht-Taschenratte / Spanish: Tuza de cara amarilla Taxonomy. Pseudostoma castanops Baird, 1852, “along the prairie road to Bent’s Fort” (near the present town of Las Animas, Colorado, USA). Cratogeomys was regarded as a subgenus of Pappogeomys by R. J. Russell in 1968, but it was returned to generic status by R. L. Honeycutt and S. L. Willams in 1982. Molecular studies show C. castanops to be sister to C. goldmani, and these two species, together with C. merriami, C. fulvescens, and C. perotensis, comprise the C. castanops species group. J. L. Patton in 2005 recognized 17 subspecies of C. castonops, subsequently reduced to two subspecies by D. J. Hafner and colleagues in 2008. Two subspecies recognized. Subspecies and Distribution. C.c.castanopsBaird,1852—SEColoradoandSWKansas,USA,southwardtoNCoahuila,NNuevoLeon,andNTamaulipas,Mexico. C. c. consitus Nelson & Goldman, 1934 — E Chihuahua and W & S Coahuila S to NE Durango, Mexico. Descriptive notes. Head-body 170-235 mm (males) and 155-215 mm (females), tail 70-105 mm (males) and 50-105 mm (females); weight 225-410 g (males) and 185-260 g (females). Male Yellow-faced Pocket Gophers are usually larger than females; this is especially pronounced in populations with larger average body size. As in all species of pocket gophers, adult body size can be heavily influenced by local climate, with small individuals in dry regions with sparse vegetation and large individuals in wet regions with denser vegetation. Pelage color also varies considerably among populations, with those living in hot, dry habitats at low elevations being much paler dorsally than populations living in moist and cool habitats at higher elevations. The Yellowfaced 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. Most individuals are pale yellowish buffto dark reddish brown dorsally and whitish ventrally. Anterior surface of each upper incisor has a single medial groove slightly displaced to its inner side. Chromosomal complement has 2n = 46 and FN = 86. Habitat. Deep sandy or silty soils that have a low density of rocks. Habitats occupied by the Yellow-faced Pocket Gopher include mesquite (Prosopis sp., Fabaceae) and cactus communities in the western part ofits distribution, native short-grass plains in the east, and broad expanses of native desert scrublands in the northern Mexican Altiplano. It is known from elevations of 10 m (near the mouth of the Rio Grande) to just over 2100 m. Food and Feeding. The Yellow-faced Pocket Gopher eats predominately fleshy, tuberous roots of desert shrubs, roots and leaves of low-growing forbs, and a limited amount of surface vegetation. Lechugilla (Agave lechuguilla, Asparagaceae) was reported to be the principal food of the Yellow-faced Pocket Gopher on the Stockton Plateau of Texas. It readily invades cultivated fields and orchards and is considered by farmers to be one of the most injurious of all pocket gopher species. The burrow system is a series of shallow feeding tunnels radiating spoke-like from a deeper, central network that contains a single nest chamber and several smaller chambers for storage of food or fecal pellets. Surface feeding activity in the immediate vicinity of the borrow entrance has been reported for the Yellow-faced Pocket Gopher. Breeding. Breeding season varies greatly across the distribution of the Yellow-faced Pocket Gopher. In Kansas, females have litters in March-April, followed by a possible second litter in late summer or early autumn. In Texas, pregnant females have been recorded in every month of the year, and individual females may give birth to three, sometimes four, litters per year. In Coahuila, Mexico, the Yellow-faced Pocket Gopher has two distinct breeding seasons: one in winter (December—March) and another in summer (June-August). Litter sizes are 1-5 young, with an average of 2-3 young/litter. Activity patterns. Field studies show the Yellow-faced Pocket Gopher to be 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 Yellow-faced Pocket Gopheris solitary and aggressively territorial. Because it rarely leavesits burrow system,its home range is defined by size and extent ofits burrow system. Several burrow systems measured in western Texas averaged 76 m in total tunnel length. There appears to be only a single nest chamber in the burrow system, unlike the smooth-toothed pocket gophers (Thomomys) that may have several nest chambers within a single burrow system. As in most species of pocket gophers, adult sex ratio is biased in favor of females. In one study in southern New Mexico, sex ratio of immature Yellow-faced Pocket Gophers was c.1:1 but that of adults was almost 5:1 in favor of females. Status and Conservation. Classified as Least Concern on The IUCN Red Lust. Bibliography. Davidow-Henry et al. (1989), Hafner, Hafner et al. (2008), Honeycutt & Williams (1982), Linzey (2008b), Patton (1999h, 2005b), Russell (1968b).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 pages 250-251, DOI: 10.5281/zenodo.660380