California mammals

Northern Hoary Bat in California

Lasiurus cinereus

Native to California S4 Apparently Secure in California

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

IUCN Red List status

LC – Least Concern

Widespread and abundant; not at risk.

Photo: Gjon Hazard · CC BY 4.0Hoary bat in flight against blue sky, wings spread to show its yellow throat patch and heavily frosted furPhoto: Nelson Balcar · CC BY 4.0Hoary bat roosting in a tree bark hollow, frosted fur blending with the surrounding lichenPhoto: Konshau Duman · CC BY 4.0Hoary bat hanging from an exposed branch in daylight, showing its full frosted coatPhoto: Kalvin Chan · CC BY 4.0Hoary bat roosting among grapevine foliage, a typical solitary tree roost

Photo: Gjon Hazard · CC BY 4.0Hoary bat in flight against blue sky, wings spread to show its yellow throat patch and heavily frosted furPhoto: Nelson Balcar · CC BY 4.0Hoary bat roosting in a tree bark hollow, frosted fur blending with the surrounding lichenPhoto: Konshau Duman · CC BY 4.0Hoary bat hanging from an exposed branch in daylight, showing its full frosted coatPhoto: Kalvin Chan · CC BY 4.0Hoary bat roosting among grapevine foliage, a typical solitary tree roost

Northern Hoary Bat in California, by the numbers

Occasional in California 106th most recorded of 241 mammals logged in California

646 occurrence records

318 with iNaturalist photos

Records from 2000–2026.

646 total records count every California occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 638 records with a full observation date.

When to look for the Northern Hoary Bat in California

Most sightings fall in April.

638 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)

Month	Records
January	53
February	47
March	62
April	134
May	62
June	23
July	18
August	20
September	56
October	56
November	57
December	50

Monthly northern hoary bat occurrence records (iNaturalist and GBIF) in California, 2000–2026.

Seasonality

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

Occurrence map

Where Northern Hoary Bat has been recorded in California

300 records mapped · zoom and drag to explore

300 California records mapped

Notable places to look

Park, forest, or monument	iNaturalist records
Golden Gate National Recreation Area	14
Humboldt Redwoods State Park	5
Bidwell-Sacramento River State Park	5
Death Valley National Park	5
Hastings Natural History Reserve	5
Angeles National Forest	4
Pinnacles National Park	3
Santa Monica Mountains National Recreation Area	3

Protected places with the most northern hoary bat 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

County	Records
San Diego County	105
Los Angeles County	61
Santa Clara County	39
San Francisco County	33
Humboldt County	31
Marin County	31
Contra Costa County	23
Fresno County	23
San Mateo County	22
Alameda County	21
Monterey County	21
Yolo County	19
33 other counties	217

The complete county distribution, spread across 45 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Northern Hoary Bat records connect California’s feeding grounds with places suitable for daytime shelter. The Sierra Nevada, Coast Ranges, desert oases, and developed valleys create sharply different combinations of insects, flowers, caves, trees, and buildings.

Reports tend to gather near roads, towns, parks, and monitored roosts, while high ridges and open desert receive less nighttime coverage. California’s dry summers make water especially important, but records near ponds don’t establish how many bats use the surrounding landscape.

The California record set contains 318 research-grade community observations. 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.

Full species profile Northern Hoary Bat Lasiurus cinereus Size 13–15 cm5.1–5.9 in Weight 26 g0.9 oz Lifespan Up to 14 yr 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"