Bats around Boston

Boston, Massachusetts, United States

Every measure here is worked out per 5 degree square, so this covers the wider area around Boston (40° to 45° latitude, -75° to -70° 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

No bats arrived here in these weeks last year, as far as the records show.

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

SpeciesRecordsPer 1,000
Big Brown Bat Eptesicus fuscus4,340114.2
Eastern Red Bat Lasiurus borealis1,63843.1
Little Brown Bat Myotis lucifugus1,03027.1
Tricolored Bat Perimyotis subflavus2296.0
Northern Long-eared Bat Myotis septentrionalis731.9
Hoary Bat Lasiurus cinereus461.2
Silver-haired Bat Lasionycteris noctivagans240.6
Rafinesque's Big-eared Bat Corynorhinus rafinesquii200.5

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: 935 BirdWeather. Add a station to fill the gap.

Bats around Boston: arriving now and most recorded · Wildlife Network