New BirdCast Dashboard Spotlights the Hottest States and Counties for Hen Migration


Map of the continental United States showing numbers of migrant birds that passed through in autumn of 2021. Text on image: Iowa 868 million, Missouri 871 million, Texas 836 million, Alabama 872 million, Georgia 913 million.
A BirdCast information compilation depicts the highest states for hen migration throughout autumn 2021. The heaviest visitors was by way of the center of the continent, although states within the northeastern and western U.S. nonetheless obtained a whole bunch of hundreds of thousands of migrants in a season. Graphic by Audrey Carlsen. Knowledge evaluation by Adriaan Dokter. Migration information from BirdCast and eBird.

Throughout final fall’s migration season, Georgia took the highest prize for many birds— with 900 million birds migrating over the Peach State from August 1st to November fifteenth. However the birdiest evening of fall migration peaked in neighboring Alabama, the place 33 million birds flew over Baldwin County the night of October 16—the very best nightly complete for any county.

These bragging-rights stats come from the brand new on-line Migration Dashboard produced by BirdCast, a collaboration amongst scientists on the Cornell Lab of Ornithology, Colorado State College, and College of Massachusetts Amherst that makes use of climate radar and machine studying to trace and forecast hen migration. BirdCast has been monitoring nightly hen migration by way of radar throughout the usA. since 2018, however final spring this system launched the Dashboard instrument to supply real-time migration information on the county degree.

“In recent times, we’ve been capable of visualize and forecast the actions of migrating birds on a continent-wide scale,” stated BirdCast senior researcher Andrew Farnsworth, a analysis affiliate on the Cornell Lab. “That’s been fascinating, however now you may also get a really feel for what’s happening in your personal neck of the woods.”

Migration Dashboard offers realtime analytics about nocturnal hen migration, akin to flight velocity, course, and altitude. In fall 2021, BirdCast indicated that southern states like Alabama and Georgia had the very best volumes of migrating birds, which makes good sense to radar ornithologists like Farnsworth and Adriaan Dokter.

“There’s at all times an inclination for migration to pay attention east of the Gulf [of Mexico],” stated Dokter, a analysis affiliate on the Cornell Lab and member of the BirdCast staff. The explanations, he stated, lie within the primary wants of migrating birds: habitat, meals, and favorable winds.

Watch Your Nightly Hen Migration in Actual Time

In autumn as birds transfer south from their breeding grounds, they search out massive swaths of forest to shelter and refuel throughout their grueling journeys. Dokter famous that the Appalachian Mountains—that are basically 1,500 miles of unbroken timber operating from Canada to the Deep South— is especially engaging for migrants. The mountains acquire birds from throughout the East, funneling them to the vary’s southernmost factors in Georgia and Alabama.

Massive numbers of birds additionally migrate by way of Midwestern states like Iowa and Missouri. When flying on favorable tailwinds (that’s, winds blowing out of the north), migrating birds are inclined to drift eastward as a consequence of prevailing west-to-east winds throughout the continent. Once more, the birds are pushed towards Georgia and Alabama.

This confluence of bird-migration rivers—the place birds flying down the Appalachians meet birds drifting over from the Midwest—makes the Southeast a hub for nocturnal hen air visitors.

The best-volume bird-migration nights are dictated by climate.

“Birds like to migrate with good tailwinds,” stated Dokter. Certainly, the three greatest hen migration nights in fall 2021—on Sept. 22, Oct. 3, and Oct. 16—have been all the results of excessive strain methods that introduced chilly climate and favorable tailwinds out of the north. However Dokter theorizes there’s a distinction within the make-up of species on these three huge migration nights.

bar chart depicting migration intensity each night of the autumn 2021 migration season.
Patterns in migration visitors throughout autumn 2021. Bars signify migration depth every evening of the season, with the three greatest surges taking place round September 22, October 3, and October 16. Graphic by Audrey Carlsen. Knowledge evaluation by Adriaan Dokter. Migration information from BirdCast and eBird.

“It’s very possible the primary peak is extra long-distance migrants,” he stated. “Later we see birds that keep within the U.S. to winter.” In different phrases, birds like warblers that migrate all the way in which to Central and South America depart first, whereas sparrows and kinglets which have much less floor to cowl migrate later.

As for fall 2022, Dokter says the brand new BirdCast instrument provides a brand new component to birding the autumn migration. “I’m going to sit down there with Migration Dashboard, go searching, and let the birds shock me,” he says. 

Benjamin Hack’s work on this story as a scholar editorial assistant was made doable by the Cornell Lab of Ornithology Science Communications Fund, with assist from Jay Branegan (Cornell ’72) and Stefania Pittaluga.


Leave a Reply

Your email address will not be published. Required fields are marked *