California mammals

Red Tree Vole in California

Arborimus longicaudus

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

NT – Near Threatened

Close to qualifying as threatened in the near future.

Red tree vole crouched among Douglas-fir branchesIllustration: a red tree vole beside its stick nest in a conifer, painted by Louis Agassiz Fuertes (1918)
Photo: Stephen DeStefano, USGS · Public domainRed tree vole crouched among Douglas-fir branchesPhoto: Louis Agassiz Fuertes · Public domainIllustration: a red tree vole beside its stick nest in a conifer, painted by Louis Agassiz Fuertes (1918)

Red Tree Vole in California, by the numbers

Occasional in California 133rd most recorded of 241 mammals logged in California

132 occurrence records
1 with iNaturalist photos

Records from 2000–2026.

132 total records count every California occurrence from GBIF and iNaturalist; the monthly chart covers the 129 records with a full observation date.

When to look for the Red Tree Vole in California

Most sightings fall in June to July.

129 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
January4
February2
March20
April10
May7
June21
July25
August9
September6
October10
November9
December6

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

Seasonality

Year-round in California, with recorded sightings peaking in June–July, with a smaller rise in March.

Occurrence map

Where Red Tree Vole has been recorded in California

132 records mapped · zoom and drag to explore

132 California records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Trinity National Forest 6
Patrick's Point State Park 4

Protected places with the most red tree vole 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
Humboldt County 84
Sonoma County 29
Mendocino County 10
Trinity County 7
Del Norte County 2

The complete county distribution, spread across 5 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

California’s combined state files contain 132 Red Tree Vole records: 0 from iNaturalist and 132 from GBIF. It ranks 133th among 243 mammals in this California record comparison, placing it in the middle third. That’s a ranking of submitted records, not a head count of animals.

The monthly series reaches its high point in May and June, with 1 record in the busiest months. Records appear in 2 of 12 months, so the pattern shows when sightings were documented, not when the species must be present or absent.

California accounts for about 6% of the mapped GBIF records summarized on the national Red Tree Vole page. That’s a modest share of the known record footprint, though differences in survey effort can strongly shape the percentage.

Occurrence data from iNaturalist and GBIF.

Red tree vole crouched among Douglas-fir branches
Full species profile Red Tree Vole Arborimus longicaudus Size 10.7 cm4.2 in Weight 22 g0.8 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"