Thomomys townsendii (Bachman, 1839)
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publication ID |
https://doi.org/ 10.5281/zenodo.6603807 |
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DOI |
https://doi.org/10.5281/zenodo.6606770 |
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persistent identifier |
https://treatment.plazi.org/id/0131878A-0729-FF86-FF31-FBBE68D04B8E |
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treatment provided by |
Carolina |
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scientific name |
Thomomys townsendii |
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Townsend’s Pocket Gopher
Thomomys townsendii View in CoL
French: Gaufre de Townsend / German: Townsend-Taschenratte / Spanish: Tuza de Townsend
Taxonomy. Geomys townsendii Bachman, 1839 ,
“Columbia river.” Modified by V. Bailey in 1915 to “probably southern Idaho and very probably near Nampa [Canyon County],” USA .
Placed into subgenus Megascapheus . Considered a subspecies of T. umbrinus by E. R. Hall in 1981 but considered a valid species by many other specialists despite limited hybridization with 7. bottae in north-eastern California. Two subspecies recognized.
Subspecies and Distribution.
T.t.townsendBachman,1839—SnakeRiverdrainageinIdahoandECOregon,USA.
T. t. nevadensis Merriam, 1897 — Humboldt and Quinn River drainages in Nevada and SE Oregon, and Honey Lake Valley in N California, USA. View Figure
Descriptive notes. Head-body 150-230 mm (males) and 145-210 mm (females), tail 60-100 mm (males) and 55-94 mm (females); weight 200-420 g (males) and 120-310 g (females). Male Townsend’s Pocket Gophers are usually larger than females, and this is especially pronounced in populations with larger average body size. This relatively large pocket gopherhas a fusiform body shape typical of all pocket gophers, and it possesses furlined cheek pouches that open external to the mouth. Dorsal color is light brown to light grayish brown with dark gray nose,face, and post-auricular patches. Chin is white, and some individuals have white marks on top of head. Melanistic individuals may have white patches on chin or feet. Female Townsend's Pocket Gophers have four pairs of mammae, two pectoral and two inguinal. Chromosomal complement has 2n = 76 and FN = 142-148. J. L. Patton and his colleagues investigated a narrow (c.1 km) zone of hybridization between Townsend’s Pocket Gopher and Botta’s Pocket Gopher ( T. bottae ) in north-eastern California, USA, where hybrid individuals showed a substantial degree of infertility or non-viability. The authors supported the speciesstatus of Townsend's Pocket Gopher because there was no evidence of genetic introgression beyond the hybrid zone.
Habitat. Bottomland regions in the northern Great Basin of western USA, including river valleys and Pleistocene lakebeds surrounded by arid sagebrush ( Artemisia , Asteraceae ) habitats. Soils in these regions are deep, loamy, and relatively moist. Maximum elevation recorded for Townsend's Pocket Gopheris ¢.2000 m in eastern Oregon, USA.
Food and Feeding. In many parts ofits distribution, Townsend's Pocket Gopher feeds heavily on saltgrass ( Distichlis spicata, Poaceae ) and other grasses, legumes (especially alfalfa), and a large variety of cultivated plants. 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 chambersfor storage of food orfecal pellets. Surface feeding activity in the immediate vicinity of the borrow entrance has been reported for Townsend's Pocket Gopher.
Breeding. Townsend’s Pocket Gopher breeds in early spring (February-April), and females produce one or morelitters per year, each containing 3-10 young. In a study in north-eastern California, Townsend’s Pocket Gophers were promiscuous, based on female choice.
Activity patterns. Townsend's Pocket Gopheris active at any hour of the day, with periods of peak activity around dawn and dusk. In areas supporting large populations of Townsend's pocket gopher, mounds of earth produced by their digging can cover nearly 50% ofthe soil surface. It does not hibernate and is active year-round.
Movements, Home range and Social organization. Townsend's 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.
Status and Conservation. Classified as Least Concern on The IUCN Red List.
Bibliography. Bailey (1915, 1933), Hall (1981), Linzey & NatureServe (Hammerson) (2008v), Patton (2005b), Patton et al. (1984), Rogers (1991), Smith (1999), Verts & Carraway (2003).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
