California mammals

Long-tailed Pocket Mouse in California

Chaetodipus formosus

Native to California SNR Unranked in California

Not listed as nonindigenous in California by USGS NAS; native to its California range.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

Long-tailed Pocket Mouse in California, by the numbers

Common in California 79th most recorded of 233 mammals logged in California

528 occurrence records
33 with iNaturalist photos

Records from 2000–2026.

528 total records count every California occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 526 records with a full observation date.

When to look for the Long-tailed Pocket Mouse in California

Most sightings fall in April.

526 California occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly California records (table)
MonthRecords
January1
February7
March80
April155
May70
June9
July34
August13
September43
October83
November22
December9

Monthly long-tailed pocket mouse occurrence records (iNaturalist and GBIF) in California, 2000–2026.

Seasonality

Year-round in California, with recorded sightings peaking in April.

Occurrence map

Where Long-tailed Pocket Mouse has been recorded in California

300 records mapped · zoom and drag to explore

300 California records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Death Valley National Park 152
Mojave National Preserve 23
Mojave Trails National Monument 15
Joshua Tree National Park 5
Inyo Mountains Wilderness Area 3
Santa Rosa And San Jacinto National Monument 3
Eastern Kern County Onyx Ranch State Vehicular Recreation Area 2
Mecca Hills Wilderness Area 1

Protected places with the most long-tailed pocket mouse sightings, from the USGS Protected Areas Database plus named mountain ranges, good spots to look, not a full breakdown, so they don't sum to the total.

Where it's recorded in California

CountyRecords
Inyo County 318
San Bernardino County 146
Riverside County 33
Kern County 10
Imperial County 8
Mono County 5
San Diego County 5
Lassen County 1
Other localities 2

The complete county distribution, spread across 8 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Long-tailed Pocket Mouse records reflect California’s dry interior, where sandy flats, open scrub, grassland, and desert basins form a patchwork rather than one continuous habitat. The Central Valley, Mojave Desert, and eastern rain-shadow valleys differ greatly in soil and vegetation.

Agriculture, roads, and expanding towns have broken up many lowland sites, especially in the San Joaquin Valley. Reports don’t measure abundance, and the scarcity of nighttime surveys can leave suitable-looking ground with few or no mapped observations.

The California record set combines 33 research-grade community observations with 520 museum and survey records. Monthly patterns can also reflect weather and observer activity, so they shouldn’t be treated as a direct count of animals.

Occurrence data from iNaturalist and GBIF.

More mammals in California in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • NatureServe ExplorerCC-BYthe state conservation rank
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap
  • USFSpublic domainnational-forest boundaries
  • USGS Protected Areas Databasepublic domainthe named parks, forests, and refuges behind "notable places to look"