BC Conservation Data Centre: Species Summary
Perognathus parvus
Columbia Plateau Pocket Mouse
| Scientific Name: | Perognathus parvus (Peale, 1848) | ||||||||||
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| English Name: | Columbia Plateau Pocket Mouse | ||||||||||
| English Name Synonyms: |
Great Basin Pocket Mouse
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| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Riddle, B. R., T. Jezkova, M. E. Eckstut, V. Oláh -Hemmings, and L. N. Carraway. 2014. Cryptic divergence and revised species taxonomy within the Great Basin pocket mouse, Perognathus parvus (Peale, 1848), species group. Journal of Mammalogy 95:9?25. | ||||||||||
| Classification Level: | Species | ||||||||||
| Taxonomy Comments: | The English name was changed to match work done (Riddle et. al. 2014) on Perognathus parvus systematics. | ||||||||||
| Species Group: | Vertebrate Animal | ||||||||||
| Species Code: | M-PEPA | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G5 (Apr 2016) | ||||||||||
| Provincial Status: | S3 (Mar 2024) | ||||||||||
| BC List: | Blue | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | |||||||||||
| SARA Schedule: | |||||||||||
| General Status Canada: | 2 - May be at risk (2005) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Subspecies Comments: | Two subspecies occur in British Columbia-P. p. laingi and P. p. lordi (Cowan and Guiguet 1956; Nagorsen 2003). They represent low elevation and high elevation/northern populations in British Columbia. Although the high and low elevation populations in British Columbia differ in life history strategies, size, and pelage colour (Iverson 1967; Cowan and Guiguet 1956) there is little support for recognizing them as distinct subspecies or nationally significant populations (Ferell 1995; Nagorsen 2003). Their physiological differences may be a simple ecophenotypic response to different environments. Their minor divergence in pelage colour and skull size probably reflects local variation in response to different moisture regimes and growing seasons. | ||||||||||
| Identification Comments: | Illustrated identification keys for rodent species are in Nagorsen (2002, 2005b). This species could be confused with the Deer Mouse. | ||||||||||
| Global Reproduction Comments: | Reproductively active spring-summer. Gestation probably lasts about 21-28 days; 0-3 litters/year, varies with precipitation. Number of fetuses/female ranges from 2 to 8 (average about 5). Young are weaned in about 3 weeks. | ||||||||||
| Provincial Reproduction Comments: | Females breed earlier at high elevations with the pregnant females first observed in late May (Iverson 1967). At low elevations, pregnant females were not observed until early June. Female breeding ends in late July in the high elevation populations but extends until late August or early September at low elevations. The gestation period is 21 to 25 days (Verts and Kirkland 1988). Iverson (1967) reported a mean litter size of 4.9 (range 4-6) for 39 females from high and low elevations in the south Okanagan. Female Great Basin Pocket Mice generally produce one or two litters, but females living at low elevations occasionally have as many as three litters (Iverson 1967). High elevation populations produce one or two litters. Young-of-the-year generally do not breed until the following spring, although a few females born in the early spring litters will breed in their first summer (Iverson 1967). | ||||||||||
| Global Ecology Comments: | Primarily solitary. Home range has been estimated at up to 0.40 ha; varies with several factors. Population density may reach 80/ha or more in years with abundant precipitation. | ||||||||||
| Provincial Ecology Comments: | Iverson's (1967) study in the south Okanagan provides extensive data on habitat, reproduction, energetics, and diet. Walt Klenner (pers. comm.) captured this species in a number of his small mammal study grids in low elevation sites in the south Similkameen-Okanagan. His study will provide data on population densities and population dynamics over 2 years. No data exist on long term population dynamics in British Columbia; the ecology of populations living at the northern edge of the range in the Thompson River valley and the north Okanagan has not been studied. | ||||||||||
| Migration Characteristics: (Global / Provincial) | |||||||||||
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Nonmigrant: Local Migrant: Distant Migrant: Within Borders Migrant: |
Y / Y N / N N / N na / N |
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| Provincial Mobility & Migration Comments: | Based on trapping captures of marked animals, Iverson (1967) calculated home range sizes of 898 sq. m for males and 656 sq. m for females. His estimates are low compared with home range estimates for Big Sage habitats in the Columbia Plateau of Washington State (O'Farrell et al. 1975). Few data are available on dispersal but movements up to 250 m were documented by O' Farrell et al. (1975). | ||||||||||
| Habitats: (Type / Subtype / Dependence) |
Grassland/Shrub / Antelope-brush Steppe / Facultative - frequent use
Grassland/Shrub / Grassland / Facultative - frequent use Grassland/Shrub / Sagebrush Steppe / Facultative - frequent use Subterranean / Sub-soil / Obligate |
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| Global Habitat Comments: | Arid, sandy short-grass steppes; brushland covered with sagebrush, bitterbrush, and rabbit brush; pinyon-juniper woodland. Usually found in habitats with light-textured, deep soils; also among rocks. Sleeps and rears young in underground burrows. | ||||||||||
| Provincial Habitat Comments: | Restricted to the dry grasslands of British Columbia, the Great Basin Pocket Mouse inhabits arid valley bottoms and open slopes on hillsides. According to Iverson (1967) the maximum elevation inhabited by this species in the southern Okanagan Valley is 1373 m. Typical habitat (Iverson 1967) is grassland and shrub-steppe with a shrub cover of Antelope-Bush, Big Sage, and grasses such as Bluebunch Wheatgrass and Needle-grass. Sandy or lightly textured soils are preferred (Feldhamer 1979) because they provide ideal conditions for excavating burrows. At higher elevations the Great Basin Pocket Mouse is associated with Pasture Sage, or Common Rabbit-Brush habitats in clay till soil (Iverson 1967). Ponderosa Pine forest is rarely used (Iverson 1967, T.P. Sullivan, pers. comm.) but this species occupies grassland habitats disturbed by fire or grazing (Iverson 1967; W. Klenner, pers. comm.), rangeland with introduced alien plants, and disturbed sites such as road or railway embankments (Nagorsen 2003). | ||||||||||
| Food Habits: |
Granivore: Adult, Immature
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| Global Food Habits Comments: | Primarily a seed eater, but also feeds on insects and some green vegetation in spring/summer. Seeds stored in underground storage chambers. May forage in grain fields but no significant damage has been noted (Bureau of Land Management, no date). | ||||||||||
| Provincial Food Habits Comments: | From an analysis of stomach contents, Iverson (1967) demonstrated that in British Columbia the diet is about 43% seeds, 31% green vegetation (mostly grass stems), and 26% animal material (primarily arthropods). The incidence of vegetative material is highest in spring, whereas seeds increase in importance in late summer. Iverson (1967) did not identify the species of seeds eaten, but in Washington State, Kritzman (1974) found that grasses were the most common seeds in cheek pouches. Cheatgrass, an alien grass is an important food item for this rodent (O' Farrell et al. 1975). Although its seeds have a thick hull and contain toxic secondary compounds, captive Great Basin Pocket Mice readily consumed seeds of Antelope-Bush (Jenkins and Ascanio 1993). | ||||||||||
| Global Phenology: |
Crepuscular: Adult, Immature
Nocturnal: Adult, Immature |
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| Global Phenology Comments: | Little above-ground activity occurs in November-March; during this time, long periods of torpor are presumed to alternate with arousal and eating periods. Also may become torpid in summer. Active within an hour after sunset. | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
Jan: Present / Present
Feb: Present / Present Mar: Present / Active Apr: Active / Reproducing May: Reproducing / Reproducing June: Reproducing / Reproducing July: Reproducing / Active Aug: Reproducing / Reproducing Sept: Reproducing / Present Oct: Active / Active Nov: Active / Present Dec: Present / Present |
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| Provincial Phenology Comments: | The Great Basin Pocket Mouse enters daily torpor in response to cool temperatures and enters prolonged torpor (i.e. hibernation) in winter. Iverson (1967) demonstrated that the timing of when animals enter hibernation depends on elevation. High elevation populations (> 700 m) enter hibernation as early as late October; low elevation (< 500 m) populations enter hibernation in late November. Iverson (1967) speculated that this species may use torpor in August to escape heat stress. | ||||||||||
| Colonial Breeder: | N | ||||||||||
| Length(cm)/width(cm)/Weight(g): | 20/ / 31 | ||||||||||
| Elevation (m) (min / max): |
Global:
Provincial: 320 / 1373 |
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| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | The known distribution of P. parvus ranges from south-central British Columbia south through central and eastern Washington, northern and northeastern Oregon, and southwestern Idaho along the Snake River. Distribution of P. parvus overlaps with that of P. mollipilosus in 1 examined locality from north-central Oregon (Jefferson County, 10 mi. N, 5 mi. E Redmond). It is currently unknown if P. parvus occurs on the central and eastern Snake River Plain in Idaho (Riddle et al. 2014). | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | Hammerson, G. | ||||||||||
| Last Updated: | Sep 21, 1994 | ||||||||||
| Provincial Information Author: | Nagorsen, D. | ||||||||||
| Last Updated: | Mar 02, 2005 | ||||||||||
| References and Related Literature | |||||||||||
Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp. |
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Best, T. L. 1994. Perognathus alticolus. Mammalian Species No. 463:1-4. |
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Bureau of Land Management. Life History Summaries. |
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Cowan, M., and C.J. Guiguet. 1956. The mammals of British Columbia. B.C. Prov. Mus. Handb. No.11. Victoria. 413pp. |
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Feldhamer, G.A. 1979. Vegetative and edaphic factors affecting abundance and distribution of small mammals in southeast Oregon. Great Basin Nat. 39:207-218. |
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Ferrell, C.S. 1995. Systematics and biogeography of the Great Basin pocket mouse, Perognathus parvus. M.Sc. Thesis, Univ. Nevada, Las Vegas. 68pp. |
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Genoways, H. H., and J. H. Brown, editors. 1993. Biology of the Heteromyidae. American Society of Mammalogists Special Publication No. 10. 719 pp. |
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Ingles, L. G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, California. |
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Iverson, S.L. 1967. Adaptations to arid environments in Perognathus parvus (Peale). PhD. Thesis, Univ. B.C. 130pp. |
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Jenkins, S.H., and R. Ascanio. 1993. A potential nutritional basis for resource partitioning by desert rodents. Am. Midl. Nat. 130:164-172. |
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Jones, J. K., Jr., R. S. Hoffman, D. W. Rice, C. Jones, R. J. Baker, and M. D. Engstrom. 1992a. Revised checklist of North American mammals north of Mexico, 1991. Occasional Papers, The Museum, Texas Tech University, 146:1-23. |
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Kritzman, E.B. 1974. Ecological relationships of Peromyscus maniculatus and Pergonathus parvus in eastern Washington. Journal of Mammalogy 55:172-188. |
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Larrison, E.J. and D.R. Johnson. 1981. Mammals of Idaho. The University of Idaho Press, Moscow. |
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Nagorsen, D. W. 2005b. The rodents and lagomorphs of British Columbia. Royal B.C. Mus. Handb., Victoria, BC. 410pp. |
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Nagorsen, D.W. 2002. An identification manual to the small mammals of British Columbia. B.C. Minist. Sustainable Resour. Manage., and Minist. Water, Land and Air Prot., and Royal B.C. Mus., 153pp. |
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Nagorsen, D.W. 2003. Status of the Great Basin Pocket Mouse (Perognathus parvus) in British Columbia. Final draft submitted to B.C. Minist. Water, Air and Land Prot., September 2003, 30pp. |
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Nagorsen, D.W. 2004. Status of the Great Basin Pocket Mouse (Perognathus parvus) in British Columbia. B.C. Ministry of Environment, Victoria, BC. Wildlife Working Report No. WR 117. |
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O'Farrell, T.P., et al. 1975. A population of Great Basin pocket mice, Perognathus parvus, in the shrub-steppe of south central Washington. Ecol. Monogr. 45:1-28. |
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Riddle, B. R. 1995. Molecular biogeography in the pocket mice (Perognathus and Chaetodipus) and grasshopper mice (Onychomys): the late Cenozoic development of a North American aridlands rodent guild. Journal of Mammalogy 76:283-301. |
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Ryan, J. M. 1989. Comparative myology and phylogenetic systematics of the Heteromyidae (Mammalia, Rodentia). Univ. Michigan Museum Zoology Miscellaneous Publication (176):1-103. |
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Stevens, V., and S. Lofts. 1988. Species Notes for Mammals. Vol. 1 in A.P. Harcombe, tech. ed. Wildlife Habitat Handbooks for the Southern Interior Ecoprovince. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Tech. Rep. R-15. 174pp. |
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Verts, B J., and G.L. Kirkland. 1988. Perognathus parvus. Mammalian Species 318:1-8. |
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Verts, B. J., and G. L. Kirkland, Jr. 1988. Perognathus parvus. Am. Soc. Mamm., Mammalian Species 318:1-8. |
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Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. 1994. Species Summary: Perognathus parvus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).