Bats around San Francisco
San Francisco, California, United States
Every measure here is worked out per 5 degree square, so this covers the wider area around San Francisco (35° to 40° latitude, -125° to -120° longitude, about 550 km across), not the city alone. Counts are shares of all bats records in the same weeks, so busier stations do not inflate them (methods).
Arrived in the last four weeks
- Western Pipistrelle around 5 October
Expected in the next six weeks
No arrivals expected here in the next six weeks, going by last year.
Dates are last year's first regular records after at least six weeks away, with each species' own uncertainty on its page. Each species page can email you when it turns up.
Most recorded, last eight weeks
| Species | Records | Per 1,000 |
|---|---|---|
| Mexican Free-tailed Bat Tadarida brasiliensis | 29,190 | 302.2 |
| California Bat Myotis californicus | 3,605 | 37.3 |
| Big Brown Bat Eptesicus fuscus | 876 | 9.1 |
| Canyon Bat Parastrellus hesperus | 687 | 7.1 |
| Little Brown Bat Myotis lucifugus | 314 | 3.3 |
| Pallid Bat Antrozous pallidus | 274 | 2.8 |
| Townsends Big-eared Bat Corynorhinus townsendii | 52 | 0.5 |
| Western Red Bat Lasiurus blossevillii | 45 | 0.5 |
| Western Long-eared Bat Myotis evotis | 24 | 0.2 |
| Silver-haired Bat Lasionycteris noctivagans | 7 | 0.1 |
| Hoary Bat Lasiurus cinereus | 5 | 0.1 |
How well this area is covered
Watched in 12 of the last 12 weeks for bats (enough records to count; unwatched weeks say nothing about absence). Active stations here in the last 30 days: 398 BirdWeather. Add a station to fill the gap.