32. Variable Pocket Gopher Heterogeomys heterodus French: Gaufre du Costa Rica / German: Costa-Rica-Taschenratte / Spanish: Tuza variable Taxonomy. Geomys heterodus Peters, 1865, “Costa Rica.” Placed into subgenus Macrogeomys. Heterogeomys considered a subgenus of Orthogeomys by J. L. Patton in 2005 but was resurrected to genus status by T. A. Spradling and colleagues in 2016. Molecular studies suggest that H. heterodus is sister to H. cherriei. Three subspecies recognized. Subspecies and Distribution. H.h.heterodusPeters,1864—ECCostaRica. H.h.cartagoensisGoodwin,1943—CCostaRica. H. h. dolichocephalus Merriam, 1895 — NC Costa Rica. Descriptive notes. Head-body 220-275 mm, tail 85-115 mm; weight 400-915 g. Dorsal pelage of the Variable Pocket Gopher is long, moderately dense, and dark brown to almost black. Ventral pelage is lighter in color. Large nasal pad and tail are almost naked, and feet are nearly so. The Variable Pocket Gopher has a fusiform body shape typical of all pocket gophers and possesses fur-lined cheek pouches that open external to the mouth. Anterior surface of each upper incisor has a single medial groove. Chromosomal complement has 2n = 44 and FN = 82. Habitat. Deep well-drained soils, many of volcanic origin, in cool tropical forests, forest clearings, pasturelands, and cultivated fields. Elevational range is 1000-2000 m. Food and Feeding. There is no specific information available for this species, but the Variable Pocket Gopher probably feeds on roots, tubers, stems, and leaves of most plants available within the vicinity of its burrow system. It readily invades cultivated fields and pasturelands and is considered an agricultural pest wherever it occurs in contact with humans. 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. Pregnant female Variable Pocket Gophers have been captured in April. Activity patterns. There is no specific information available for this species, but the Variable Pocket Gopher is probably active at any hour of the day. One study measured peak activity between 08:00 h and 14:00 h in March—-May, and another study showed peaks of activity between 06:00-08:00 h and 12:00-14:00 h in December—January. It does not hibernate and is active year-round. Movements, Home range and Social organization. The Variable Pocket Gopher is solitary and aggressively territorial. Because it rarely leaves its burrow system, its home range is defined by size and extent of its burrow system. A radio-telemetry study estimated average home range sizes of 325 m* for males and 233 m?* for females, with larger individuals having larger home ranges. Status and Conservation. Classified as Least Concern on The IUCN Red List (as Orthogeomys heterodus). Bibliography. Bonino (1994), Patton (2005b), Reid & Emmons (2008), Spradling et al. (2016), Sisk & Vaughan-Dickhaut (1984), Sudman & Hafner (1992).

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 249, DOI: 10.5281/zenodo.6603807