Total birds

122100 Birds have crossed Bexar County so far tonight (est.)

Starting: Mon, Apr 28, 2025, 8:10 PM CDT

Learn more

Live migration traffic

271,400 Birds now in flight (est.)
Direction: N
Speed: 32 mph
Altitude: 2,300 ft
Recorded: Mon, Apr 28, 2025, 9:30 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's happened so far tonight...

Birds in flight

Tonight, Apr 28
Historic
10 PM CDT1 AM4 AM0700K

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

10 PM CDT1 AM4 AM035 mph

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

Altitude

Tonight, Apr 28
Historic
10 PM CDT1 AM4 AM03000 ft

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 so far this season...

Birds in flight (nightly avg.)

Spring 2025
Historic
MarAprMayJun0700K

During spring migration, most birds pass through the contiguous U.S. from mid-April to mid-May.

Total birds crossed

Spring 2025
Historic
MarAprMayJun0200M

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