Geomys breviceps

Baird's Pocket Gopher
(*Geomys breviceps*)
Baird's Pocket Gopher (Geomys breviceps)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Castorimorphi
Superfamily:	Geomyoidea
Family:	Geomyidae
Subfamily:	Geomyinae
Tribe:	Geomyini
Genus:	Geomys
Subgenus:	Geomys (subgenus)
Binomial details
	Geomys breviceps S. F. Baird, 1855
Other resources
	Full taxonomic details at MDD

From Welborn & Light (2014): "The Baird's Pocket Gopher (Geomys breviceps) is a solitary, fossorial rodent found throughout areas of Texas, Arkansas, Oklahoma, and Louisiana. These rodents are highly modified morphologically for an underground lifestyle, often resulting in limited vagility and isolated populations."

Description

From Sulentich et al. (1991): "The body is covered by short, fine hair; pelage is pale brown to black, usually paler ventrally. Large, fur-lined external cheek pouches are used for transporting food. Eyes are small and ears are reduced. Tail is shortened, thickened, and naked, except for a few hairs at the base. The front feet have long, curved claws used for digging, whereas claws on the hind feet are smaller."

Museum specimens

Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852.
Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852.

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
Texas	Schmidly & Bradley (2016)	208	61	26

Skull

Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852. Dorsal view of the skull.
Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852. Ventral view of the skull. Note that part of the skull is damaged.
Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852. Lateral view of the skull.
Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852. Dorsal view of the mandible.
Holotype: USNM 156/1138. Geomys breviceps breviceps. Adult female. Prairie Mer Rouge, Morehouse Parish, Louisiana. Collected 1852. Lateral view of the left mandible.

Distribution and taxonomy notes

From Hoffman et al. (2024): "Lowery (1974) regarded all pocket gophers in Louisiana as Geomys bursarius. That species complex was then split, with all Louisiana gophers being assigned to G. breviceps (Honeycutt and Schmidly 1979). More recent genetic analysis has further split Louisiana gophers into three distinct species (Bradley et al. 2023). The species retained as Geomys breviceps can be found as a small, isolated population from Morehouse Parish in northeastern Louisiana. Several new specimens have been collected since Lowery (1974), however no parish records were reported."

A new species of Geomys not yet described in Louisiana can be found in west-central and northwestern Louisiana, but additional research is needed to determine their distribution (Bradley et al., 2023; Hoffman et al., 2024) . From Bradley et al. (2023): "G. b. sagittalis differed from other populations of G. breviceps by values ranging from 6.85 to 7.96%; however, we are reluctant to formerly revise this taxon until additional samples from eastern Texas, Louisiana, and Arkansas can be included in a genetic analysis."

References

Bradley RD, Pham AT, Rich KA, Roberts EK, Soniat TJ, Poehlein CM, Mills MN, Ballard M, Pitts RM, Lindsey LL, Halsey MK. 2023. Genetic identification of pocket gophers (Genera Cratogeomys, Geomys, and Thomomys) in Texas and surrounding areas. Museum of Texas Tech University.

Hoffman JD, Lester C, Doucet D, Iguwe D. 2024. Updated Checklist and Distribution of Wild Terrestrial Mammals in Louisiana. Museum of Texas Tech University. https://www.depts.ttu.edu/nsrl/publications/downloads/OP389.pdf

Honeycutt RL, Schmidly DJ. 1979. Chromosomal and morphological variation in the plains pocket gopher, Geomys bursarius, in Texas and adjacent states. Occasional Papers, The Museum, Texas Tech University 58:1–54.

Lowery Jr GH. 1974. The mammals of Louisiana and its adjacent waters. Baton Rouge (LA, USA): Louisiana State University Press.

Schmidly DJ, Bradley RD. 2016. The mammals of Texas. Austin (TX, USA): University of Texas Press.

Sulentich JM, Williams LR, Cameron GN. 1991. Geomys breviceps. Mammalian Species (383):1-4.

Welborn SR, Light JE. 2014. Population genetic structure of the Baird's pocket gopher, Geomys breviceps, in eastern Texas. Western North American Naturalist 74(3): 325-334.