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Montana Field Guide

Montana Field Guides

Hispid Pocket Mouse - Chaetodipus hispidus

Potential Species of Concern

Global Rank: G5
State Rank: SU

Agency Status
USFWS:
USFS:
BLM:
FWP SWAP: SGIN


 

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General Description
The pelage of the Hispid Pocket Mouse is harsh, with a rump patch of noticeable spiny bristles. It is ochraceous-buff above and mixed with blackish hairs, the belly is white, and separated from the back by a distinctive lateral stripe of buffy hairs. The tail is sharply bicolored, dark to blackish above and white below, and is equal to or shorter than the length of the head and body. It has fur-lined cheek pouches, as in other pocket mice, but the hind feet are naked. Adults from Nebraska attain the following body measurements: total length 203 to 237 millimeters; tail length 93 to 114 millimeters; hind foot length 23.5 to 29.5 millimeters; and mean weight 32.0 grams (Paulson 1988).

Respective measurements for the lone specimen from Montana are total length 191 millimeters, tail length 94 millimeters, hind foot length 28 millimeters, and weight 33.2 grams (Pefaur and Hoffmann 1971).

Diagnostic Characteristics
The Hispid Pocket Mouse is the largest pocket mouse in Montana and is distinguished by its rough dorsal pelage and the naked soles of its hind feet. On the skull, the mastoids do not project beyond the occipital plane and the auditory bullae are clearly separated. The combination of grooved incisors, hypsodont molars, perforate nasal septum, and fur-lined external cheek pouches distinguish the hispid pocket mouse from other non-heteromyid rodents. For other heteromyid species in Montana, Ord's Kangaroo Rat (Dipodomys ordii) also differs by having greatly elongated hind legs, hind foot length more than 30 millimeters, and the mastoid (rear) region of the skull greatly expanded. The Olive-backed Pocket Mouse (Perognathus fasciatus) also has an unlobed antitragus (fleshy projection) in the ear, occipitonasal length (anterior tip of nasal bone to posterior tip of occipital bone at base of skull) less than 24 millimeters, a uniformly-colored tail, and a hind foot length less than 20 millimeters. The range of the smaller Great Basin Pocket Mouse does not overlap in Montana with the Hispid Pocket Mouse (Foresman 2012a, 2001b).

Species Range
Montana Range

Click the legend blocks above to view individual ranges.

Western Hemisphere Range

 


Summary of Observations Submitted for Montana
Number of Observations: 9

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Migration
The Hispid Pocket Mouse is non-migratory; no information on dispersal is available.

Habitat
The only Montana record for Hispid Pocket Mouse occurred on a north-facing slope that supported grassland dominated by Stipa comata, Carex filifolia, Andropogon scoparium, Agropyron smithii, Aristada longiseta, and Bouteloua gracilis (Pefaur and Hoffmann 1971). Information from other parts of its range suggests that the Hispid Pocket Mouse prefers prairie areas with sparse or moderate vegetation, and has been found in a variety of dry grassland and shrub-grassland habitats. It also occurs in rocky or gravelly areas with heavy soils, not being restricted to sandy soils as are other prairie pocket mice. It has also been found in irrigated cornfields and hayfields. Sleeping and birthing occur in underground burrows (Paulson 1988, Seabloom 2002).

Ecological Systems Associated with this Species
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.  If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2012.  Mammals of Montana.  Second edition.  Mountain Press Publishing, Missoula, Montana.  429 pp.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Food Habits
The Hispid Pocket Mouse eats mostly seeds of grasses, forbs, shrubs, and cacti in winter (81% of the diet in parts of Texas), but also consumes green leaves and some insects (mostly ground beetles) in spring. Large quantities of seeds are stored underground for winter use (Jones et al. 1983, Paulson 1988). The diet in Montana is unknown.

Ecology
Hispid Pocket Mice are generally solitary and nocturnal. Unlike some other pocket mice, Hispid Pocket Mice are active all year. They leave mounds of dirt at the multiple entrances to their burrows, and entrances are often plugged during the day. Burrows are often dug at the base of shrubs or rock outcrops, and seeds are stored in shallow underground chambers. Predators include rattlesnakes, and most nocturnal carnivorous mammals and birds; Great Horned Owls in Nebraska and Oklahoma prey on this species (Jones et al. 1983, Clark and Stromberg 1987, Paulson 1988). In Montana, other small mammals found in sympatry with Hispid Pocket Mouse included Prairie Vole, Olive-backed Pocket Mouse, Meadow Jumping Mouse, Deer Mouse, and Western Harvest Mouse (Pefaur and Hoffmann 1971).

Populations never seem to be especially dense, thus estimates of density, home range size, and dispersal are not available.

Reproductive Characteristics
No information specific to Montana is documented. The single individual captured in Montana (in mid-July) was a nulliparous subadult female (Pefaur and Hoffmann 1971).

Throughout its range very little is known about the reproductive biology of this species. It breeds in spring and summer in the north, probably throughout the year in the south, and likely produces 1 to 2 litters of 2 to 9 young; August and September females from South Dakota and Nebraska carried 5 to 6 fetuses (Jones et al. 1983, Paulson 1988).

Management
No special management activities have been developed or implemented for this species in Montana. A thorough small mammal survey of appropriate grassland and shrub-grassland habitats in southeastern Montana is desirable to define the distribution and relative abundance of this species in the state.

References
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Citation for data on this website:
Hispid Pocket Mouse — Chaetodipus hispidus.  Montana Field Guide.  .  Retrieved on , from