A tiny mouse with external fur-lined cheek pouches. Endemic to a tiny region of coastal Southern California; thought extinct from 1971 to 1993; only ~5,000 individuals remain.

Native status: Native; federally endangered

§ Quick facts

SizeBody 5.5–8 cm (2.2–3.1 in); tail 6–8 cm
Weight6–9 g — among the smallest US mammals
LifespanWild 1–3 years; captive 7
OrderRodentia
FamilyHeteromyidae

§ Encyclopedia

The Pacific pocket mouse, Perognathus longimembris pacificus, is endemic to California. It lives in sandy coastal soils of the coastal sage scrub ecoregion. It eats seeds and some insects. It was believed to be extinct until 1993, when a small population was discovered. It is now a federally listed Endangered animal species.

Source: Wikipedia — Pacific pocket mouse Licensed under CC BY-SA 4.0

§ Identification

Field marks. Tiny golden-buff mouse with white belly, large dark eyes, long tail. External cheek pouches barely visible when not stuffed with seeds.

Similar species. Other pocket mouse species (different ranges, larger). Deer Mouse (much larger, no cheek pouches).

Voice. Generally silent; soft squeaks.

§ Diet & behavior

Diet. Seeds of native grasses and forbs, stored in external fur-lined cheek pouches and cached in underground burrows.

Behavior. Smallest North American pocket mouse. Endemic to coastal sage scrub of southern California; presumed extinct from 1970–1993 until small population rediscovered. Federally endangered (1994). Hibernates seasonally (rare for a mouse). Captive breeding at San Diego Zoo Safari Park has produced thousands of mice for reintroduction since 2012.

§ Range

Southern California coast

§ Habitat

Coastal dune scrub and sage scrub

§ Threats

Coastal development, off-road vehicles, urban predation by cats.

§ Conservation status

According to the IUCN Red List, the pacific pocket mouse is currently classified as Endangered.

§ What helps

Support coastal habitat protection. Keep cats indoors. Donate to San Diego Zoo Wildlife Alliance Pocket Mouse Recovery.

Support our work More ways to help

§ Further reading

§ Sources cited

  • USFWS Pacific Pocket Mouse Recovery
  • San Diego Zoo Wildlife Alliance
  • The Nature Conservancy
  • IUCN Red List 2016