Mammal Species of the World
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Western U.S. and northwestern Mexico: southeastern Oregon and southwestern Idaho south through eastern, central and southern California, Nevada, western and southern Utah, and scattered parts of Arizona to northern Baja California and western Sonora. Does not occur in central California west of the Sierra Nevada (Williams et al. 1993).
Length: 15 cm
Weight: 9 grams
Size in North America
Average: 131 mm
Range: 110-151 mm
Range: 6.5-10.5 g
Differs from CHAETODIPUS spp. in softer pelage that lacks spines or bristles (see Hall 1981 for cranial differences between CHAETODIPUS and PEROGNATHUS). Differs from P. ALTICOLUS, P. XANTHONOTUS, P. PARVUS, and P. FORMOSUS in smaller hind foot (less than 20 mm vs. more than 20 mm), unlobed antitragus, and occipitonasal length usually less than 24 mm rather than usually more than 24 mm (Hall 1981). Differs from P. FASCIATUS, P. FLAVUS, and P. FLAVESCENS in having the tail longer than the head and body rather than equal to or shorter than the head and body. Adults differ from P. AMPLUS in smaller size (maximum total length 15 cm vs. 17 cm) and shorter tail (usually 67-81 mm vs. 75-88 mm; less than 75% of head and body length in LONGIMEMBRIS, more than 75% in AMPLUS) (Hall 1981, Hoffmesiter 1986); see Hoffmeister (1986) for a detailed account of the differences between the very similar P. LONGIMEMBRIS and P. AMPLUS. Differs from P. INORNATUS in smaller mastoidal bullae.
Habitat and Ecology
The subspecies of P. longimembris currently of conservation concern occurs in grassland, alluvial sage scrub, and coastal sage scrub habitats.
Comments: Sandy soil in valleys; firm sandy soil, overlain with pebbles, on slopes with widely spaced shrubs. In sagebrush, creosote bush, and cactus communities in Lower and Upper Sonoran life zones. Young are born in a nest in an underground burrow.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Feeds primarily on seeds, plus green vegetation in spring. Forages mainly under shrub canopy. Stores food in underground burrow.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
10,000 to >1,000,000 individuals
Primarily solitary. Populations may fluctuate markedly from year to year and seasonally. In some areas this is the most abundant mammal; populations have been estimated to be as high as 400/acre (Hall 1946); other estimates generally have been not more than about 1-6/ha (see Zeiner et al. 1990). Home range size generally averages not more than a few hectares (see Zeiner et al. 1990).
Life History and Behavior
Comments: Remains in den during severe weather. Not active above ground during cold weather (Hall 1946); hibernates 6.5 months in southeastern California (Kenagy and Bartholomew 1985). In spring most active 2-5 hours after sunset, second peak just before sunrise (Hoffmeister 1986).
Lifespan, longevity, and ageing
Breeding season generally peaks in spring, varies with temperatures, food supply, and plant growth. Produces 1 (usually) or 2 litters/year, 2-8 young/litter. Gestation lasts 21-31 days. Young are weaned in 30 days. Sexually mature in 2-5 months. May not reproduce in years with below average precipitation (Kenagy and Bartholomew 1985).
Molecular Biology and Genetics
Barcode data: Perognathus longimembris
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Perognathus longimembris
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large range in western North America; common in many areas.
Little pocket mouse
The little pocket mouse (Perognathus longimembris) is a species of rodent in the family Heteromyidae. It is found in Baja California and Sonora in Mexico and in Arizona, California, Idaho, Nevada, Oregon and Utah in the United States. Its natural habitat is subtropical or tropical dry lowland grassland. It is a common species and faces no particular threats and the IUCN has listed it as being of "least concern".
Five mice of this species travelled into space and orbited the Earth and Moon in an experiment on board the Apollo 17 command module in December 1972. Four of the mice survived reentry. Six other little pocket mice were sent into orbit with Skylab 3 in July 1973, though these animals died only 30 hours into the mission due to a power failure.
The little pocket mouse inhabits arid and semiarid habitats with grasses, sagebrush and other scrubby vegetation. It is nocturnal and has a burst of activity for the first two hours after sunset and then sporadic activity through the rest of the night. It hibernates in winter and is only active between April and November with numbers building up rapidly in the spring to peak in June and July. It forages for seeds, plant material and small invertebrates which it carries back to its burrow in its cheek pouches.
The little pocket mouse is common within most of its range although it is scarce in Baja California. The population appears to be steady and no particular threats have been identified for this species so the International Union for Conservation of Nature has assessed it as being of "least concern".
- Linzey, A.V. (2008). Perognathus longimembris. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 22 January 2009. Database entry includes a brief justification of why this species is of least concern
- Haymaker, W., Look, B., Benton, E. & Simmonds, R. Biomedical Results of Apollo. Chapter 4: The Apollo 17 Pocket Mouse Experiment. NASA SP-368, 1975.
- Souza, Kenneth, Robert Hogan, and Rodney Ballard, eds. Life into Space: Space Life Sciences Experiments. NASA Ames Research Center 1965—1990. Washington D.C.: National Aeronautics and Space Administration, 1995. NASA Reference Publication-1372 (online version).
- Borkowski, G., Wilfinger, W. & Lane P. "Laboratory Animals in Space," Animal Welfare Information Center Newsletter, Vol. 6 No. 2-4, Winter 1995/1996.
- O'Farell, Michael J. (1974). "Seasonal Activity Patterns of Rodents in a Sagebrush Community". Journal of Mammalogy 55: 809–823. doi:10.2307/1379409. JSTOR 1379409.
Names and Taxonomy
Comments: Has been regarded as possibly conspecific with P. amplus (Hoffmeister 1986); amplus and longimembris were regarded as distinct species by Jones et al. (1992) and Patton (in Wilson and Reeder 1993, 2005). McKnight (1995) examined mtDNA variation in populations in and around Arizona and concluded that P. amplus and P. longimembris are distinct lineages that have completed the speciation process. Williams et al. (1993) referred P. l. psammophilus (and synonym sillimani) to P. inornatus. Based on molecular data, Riddle (1995) found a phylogenetic distinction between P. longimembris and P. inornatus, though these taxa formed a clade relative to P. amplus.
See McKnight and Lee (1992) for information on karyotypic variation. See Best (1994) for a key to the species of Perognathus.