California mammals

California red tree mouse in California

Arborimus pomo

Native to California S3 Vulnerable 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

NT – Near Threatened

Close to qualifying as threatened in the near future.

Arborimus pomoSonoma Tree Vole, California, US imported from iNaturalist photo 14508141Sonoma Tree Vole (Arborimus pomo)
Photo: Chris Sulots · CC BY 4.0Arborimus pomoPhoto: (c) Chris Sulots, some rights reserved (CC BY) · CC BY 4.0Sonoma Tree Vole, California, US imported from iNaturalist photo 14508141Photo: Chris Sulots · CC BY 4.0Sonoma Tree Vole (Arborimus pomo)

California red tree mouse in California, by the numbers

Occasional in California 152nd most recorded of 241 mammals logged in California

495 occurrence records
63 with iNaturalist photos

Records from 2000–2026.

495 total records count every California occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 493 records with a full observation date.

When to look for the California red tree mouse in California

Most sightings fall in March.

493 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
January18
February39
March84
April43
May36
June32
July44
August37
September56
October34
November45
December25

Monthly california red tree mouse occurrence records (iNaturalist and GBIF) in California, 2000–2026.

Seasonality

Year-round in California, with recorded sightings peaking in March, with a smaller rise in September.

Occurrence map

Where California red tree mouse has been recorded in California

300 records mapped · zoom and drag to explore

299 California records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Unnamed site - California Department of Parks and Recreation 3
Patrick's Point State Park 1
Jackson Demonstration State Forest 1

Protected places with the most california red tree 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
Sonoma County 319
Humboldt County 96
Mendocino County 55
Trinity County 13
Other localities 12

The complete county distribution, spread across 4 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

California red tree mouse reports are scattered through every month, without a single sustained season. March is highest in the supplied monthly series, while September and November form smaller rises and January is quietest; that differs from the broader seasonality summary, which highlights April, August, and October.

The file suggests the Sierra Nevada, Los Padres National Forest, and Central Valley but supplies no place counts to show how records relate to those settings. NatureServe ranks the species S3, vulnerable, in California. The 495 reports document an uneven observation record rather than statewide abundance or a hierarchy of sites.

Occurrence data from iNaturalist and GBIF.

Arborimus pomo
Full species profile California red tree mouse Arborimus pomo Size 9.9 cm3.9 in Weight 34 g1.2 oz View the full profile

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"