Total birds

20882000 Birds crossed Alabama this night (est.)
High

Starting: Tue, Sep 21, 2021, 6:50 PM CDT

Ending: Wed, Sep 22, 2021, 6:30 AM CDT

Learn more

Peak migration traffic

43,558,900 Birds in flight (est.)
High
Direction: SSE
Speed: 16 mph
Altitude: 2,700 ft
Recorded: Tue, Sep 21, 2021, 8:50 PM CDT
Not all birds may fully cross a region in one night, resulting in a greater number of birds in flight than total birds crossed.

Here's what happened across this night...

Birds in flight

Birds usually begin to migrate 30 to 45 minutes after sunset, with the greatest number in flight two to three hours later.

Flight direction and speed

Birds tend to migrate southward in autumn, but seasonal timing, weather, and geography alter their flight directions and speeds.

Altitude

Migrating birds regularly fly up to 10,000 feet above ground, although seasonal timing and weather conditions dramatically impact their distributions.

Note: Direction, speed, and altitude may be unreliable when the number of birds in flight is low. In such cases, chart data may include gaps.

And across this season...

Birds in flight (nightly avg.)

During fall migration, most birds pass through the contiguous U.S. from early September through October.

Total birds crossed

This is the estimated total number of birds that have fully crossed this region. The curve rises quickly during peak migration and levels off at the end of the season.

Expected nocturnal migrants

Powered by eBird
Nocturnally migrating species most likely to arrive or depart this region at this time of year, based on frequency of observations

Loading...

Powered by

Cornell Lab of Ornithology
Colorado State University
UMass Amherst