|The Mammals of Texas -
Desert Pocket Gopher
Rodentia : Family Geomyidae : Geomys
Description. A dull, pale-brown
pocket gopher, with two longitudinal grooves on outer
face of each incisor; feet and underparts white. External
measurements average: (males) total length, 262 mm; tail,
79 mm; hind foot, 33 mm; (females) 243-74-32 mm. Weight;
males, 198-254 g; females, 165-207 g. Dental formula as
Distribution in Texas. Restricted in
Texas to the Trans-Pecos, where it has been taken at
several localities in the cottonwood-willow association
along the Rio Grande in El Paso and Hudspeth counties.
Habits. Near El Paso, these
gophers are especially common along irrigation ditches in
the sandy river-bottom area. They seemingly cannot
tolerate clayey or gravelly soils, a characteristic
common to all species of Geomys. Their mounds are
large and conspicuous, and often one animal will throw up
20 to 30 of them in a relatively short time.
Their underground habits are not
well-known. Seth Benson reports finding flowers and cut
stems of a composite (Baileya) in their burrows.
Doubtless, these were being eaten. Other than this plant
and cultivated alfalfa, their food preferences have not
Raymond Lee captured two gravid females
near El Paso on June 28 and one on August 8. Numbers of
embryos were six, four, and four, respectively. Young
individuals have been captured in late June, July, and
August. These data indicate a prolonged breeding season
and suggest that adult females bear more than one litter
Where concentrated in numbers in
farming areas, they may do considerable damage.
Elsewhere, their burrowing activities are largely
beneficial. Frank Blair observed that the bunch grass Andropogon
in New Mexico was intimately associated with the mounds
of this pocket gopher. The grass appeared to grow more
successfully on old gopher mounds than on the valley
floor. The excrement of the gophers helped to fertilize
Remarks. Using karyotypic and
electrophoretic analyses, David Hafner and Kenneth Geluso
found shared genetic characters in G. arenarius
knoxjonesi, then considered
a subspecies of G. bursarius. These similarities
were not sufficient to combine G. arenarius with G.
bursarius; however, when Robert Baker et al.
recently elevated G. knoxjonesi to full specific
status, based on mitochondrial DNA analysis, the
taxonomic status of G. arenarius was left in
question. At this time it is uncertain whether
Jones pocket gopher and the desert pocket gopher
indeed represent separate species, or if further detailed
study of these taxa will show that combining the two as a
single species will be warranted. It is distinctly
possible that in the future G. arenarius will be
shown to be merely an isolated population of the similar G.