Spring Bird Migration Underway

Posted on: April 26th, 2017 by Leslie_Zucker

Are you wondering when you’ll hear the sweet song of the yellow warbler again? Check out the likely arrival date of your favorite feathered inhabitant of the Ashokan watershed at Cornell’s BirdCast webpage. (Yellow warblers are just beginning to return from their winter homes to breed in forests of the Northeast!) If you really want to keep track of things, you can watch radar.

According to Audubon educator Larry Federman, we can keep track of bird migration by going to the National Weather Service website’s radar page and use the “Composite Loop” feature. If you look on less rainy evenings, you’ll see blue circular “blobs” expanding – that’s the radar echoes of migrating birds!


Larry advises that the best time for radar observations is just after dark – our songbirds migrate at night so folks can see the blue circular forms widen and move to the north as night progresses. Also, if you are inclined, go outside and listen for flight calls of the migrating birds!

To view migrating birds “in person”, the best time is at first light. The birds will be most active as they forage for food to replenish what they’ve used up during the evening’s flight. People should look for budding trees and flowers that attract insects – that’s what the birds will be looking for.

In addition to radar, new technologies such as tiny geolocators are allowing researchers to track bird movements.


On this NEXRAD radar image from May 1, 2016, the bright green and yellow swirls represent precipitation in storms and the blue blobs, clustered along the Gulf and Atlantic coasts, are mostly large numbers of migratory birds. Image courtesy of the BirdCast project, whose work in the Gulf of Mexico region is funded by the Southern Company and National Fish and Wildlife Foundation.