Thomomys talpoides
| Northern Pocket Gopher
(Thomomys talpoides) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Castorimorphi |
| Superfamily: | Geomyoidea |
| Family: | Geomyidae |
| Subfamily: | Geomyinae |
| Tribe: | Thomomyini |
| Genus: | Thomomys |
| Binomial details | |
| Thomomys talpoides (J. Richardson, 1828) | |
| Other resources | |
| Full taxonomic details at MDD | |
The Northern Pocket Gopher (Thomomys talpoides) is common in a variety of habitats with soils suitable for burrowing. The species shows wide geographic variation in color and size.
Description
From Armstrong (2010) for Colorado: "The northern pocket gopher is a small gopher whose color varies geographically from dark brown or yellow-brown to pale, grayish yellow."
From Verts and Carraway (1999) for Oregon: "The pelage of T. talpoides is long, fine, and silky in winter, thin and harsh in summer (Bailey, 1915). The underfur is plumbeous, but the dorsal overpelage is rich brownish or brownish gray grading to buff on the venter. The chin is white and postauricular patches [area behind the ear] blackish or grayish black. The naked tail commonly is brownish with a white tip and the feet commonly are white or partly white (Durrant, 1952; Hall, 1946; Verts and Carraway, 1998). One or more molt lines commonly dissect the pelage."
Museum type specimens
The holotype for the species is located in the Natural History Museum of London (formerly the British Museum of Natural History). As of April 2026, access to the collection is restricted while it is being relocated. Images of the holotypes for the subspecies Thomomys talpoides agrestis and Thomomys talpoides bridgeri are provided below.
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Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907.
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| California | Jameson & Peeters (2004) | 170–225 | 47–70 | 24–30 | 5–6 | 74–110 |
| Colorado | Armstrong et al. (2010) | 165–250 | 45–75 | 25–31 | 5–7 | 100–150 |
| Minnesota | Hazard (1982) | 220–250 | 58–80 | 29–33 | 7–9 | 114–195.4 |
| North Dakota | Seabloom et al. (2020) | 235 | 64 | 30 | 8 | 160 |
Skull
The holotype for the species is located in the Natural History Museum of London (formerly the British Museum of Natural History). As of April 2026, access to the collection is restricted while it is being relocated. Images of the skull for the holotype for the subspecies Thomomys talpoides agrestis are provided below.
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Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. Dorsal view of the skull. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. Ventral view of the skull. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. Lateral view of the skull. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. Dorsal view of the mandible. -
Holotype: USNM 150725. Thomomys talpoides agrestis. Adult female. Medano Ranch, San Luis Valley, Alamosa County, Colorado. Collected 29 October 1907. Lateral view of the mandible.
Similar species
Key to the species of Thomomys by Verts and Carraway (2005)
Comparison with Thomomys clusius
From Cudworth and Grenier (2015): "Thomomys clusius can be distinguished from its sympatric congener, T. talpoides (northern pocket gopher), by its small size, lack of dark auricular patches [dark patches of fur behind the ear], and white fringe on the ears, as opposed to the dark fringe on T. talpoides (Thaeler and Hinesley 1979). The presence or absence of an auricular patch may be especially useful in field identification (Keinath et al. 2014).
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Wyoming Pocket Gopher (Thomomys clusius) photographed by Britt Brito. © Britt Brito. -
Northern Pocket Gopher (Thomomys talpoides) photographed by ML Watson in Conejos County, Colorado.
Comparison with Geomys bursarius
The pelage of Thomomys talpoides and the Plains Pocket Gopher (Geomys bursarius) vary geographically, but it differs from Geomys bursarius in having postauricular patches (area behind the ear) that are blackish or grayish black (Verts and Carraway, 1999).
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Plains Pocket Gopher (Geomys bursarius) photographed by Yinan Li in Reno County, Kansas. -
Northern Pocket Gopher (Thomomys talpoides) photographed by ML Watson in Conejos County, Colorado.
References
Armstrong DM, Fitzgerald JP, Meaney CA. 2010. Mammals of Colorado, Second Edition. Denver (CO, USA): University Press of Colorado.
Bailey V. 1915. Revision of the pocket gophers of the genus Thomomys. North American Fauna 39:1-13.
Cudworth NL, Grenier MB. 2015. Thomomys clusius (Rodentia: Geomyidae). Mammalian Species 47(923):57-62.
Hall ER. 1946. Mammals of Nevada. Berkeley and Los Angeles (CA, USA): University of California Press.
Hazard EB. 1982. The mammals of Minnesota. Minneapolis (MN, USA): University of Minnesota Press.
Jameson EW, Peeters HJ. 2004. Mammals of California (No. 66). Berkeley (CA, USA): University of California Press.
Durrant SD. 1952. Mammals of Utah: taxonomy and distribution. University of Kansas Publications, Museum of Natural History, 6:1-549.
Seabloom R, Hoganson JW, Jensen WF. 2020. The mammals of North Dakota. Fargo (ND, USA): North Dakota State University Press.
Verts BJ, Carraway LN. 1998. Land mammals of Oregon. Berkeley (CA, USA): University of California Press.
Verts BJ, Carraway LN. 1999. Thomomys talpoides. Mammalian Species (618):1-11. https://doi.org/10.2307/3504451