Weather and Songbird Migration

Weather & Songbird Migration

April 16, 2008

Dr. David Aborn

Dear Students:
As predicted, it was another good week for fallouts. That cold front dropped temperatures from the 70's and 80's down to the 50's and 40's across much of the country. Some people were sunbathing one day and shoveling snow the next!

Migrating birds didn't like the surprise from the north either, and it was a good weekend for birders along the Gulf coast. High Island, Texas had a nice fallout, with 20 warbler species seen, including many Prairie Warblers and Golden-winged Warblers, along with their first Kentucky warblers, Blackburnian Warblers, American Redstarts, and Swainson's Thrushes. Louisiana and Alabama each reported 16 warbler species, as well as many Indigo Buntings and Rose-breasted Grosbeaks, as well as the first Baltimore Orioles, Acadian Flycatchers, and Gray Catbirds.

Fallouts Followed the Weather Front
As the front moved east, so did the fallouts. Kennesaw Mountain in northern Georgia lived up to its reputation as being a good place to see migrants, with 13 warbler species seen, including the first Cerulean Warblers, and Black-throated-blue Warblers. Here in Tennessee, I was able to get a few hours of banding in on Monday before the rains came. I banded the first Blue-winged Warbler of the year, and I saw or heard Hooded Warblers, Black-and-white Warblers, Common Yellowthroats, and a Scarlet Tanager. Other people I know reported a Cerulean Warbler and an Indigo Bunting.

Grounded Migrants Headed North
While I was waiting for the front to arrive, farther west the winds had already shifted, allowing birds grounded over the weekend to move north. People in Missouri did especially well, reporting lots of Chimney Swifts, along with Eastern Wood-Pewees, Yellow-throated Warblers, and Yellow-breasted Chats. Much of the northern US saw their first migrants of the year. Many Tree Swallows were seen in Minnesota, Massachusetts, New Hampshire, and Maine, while upstate New York had their first Louisiana Waterthrush and Rose-breasted Grosbeak.

Good Birding in the West Too
The western US didn't miss out on the action, either. Birders in southeastern Arizona and New Mexico saw many Grace's Warblers, Lucy's Warblers, Wilson's Warblers, Yellow Warblers, Ash-throated Flycatchers, Gray Flycatchers, and Black-headed Grosbeaks. A bander near Chico, California, had good numbers of Black-headed Grosbeaks, Wilson's and Nashville Warblers, Cassin's Vireos, and Yellow-breasted Chats.

What to Expect This Week
This week does not look to be a good one for fallouts. Take a look at the weather map:

A front is moving across the country, but it is not a strong one. While this weak front will probably still force birds to land, we probably won't see the numbers we've seen over the past 2 weeks. Nonetheless, we are approaching the peak of migration in the southern US, and things are picking up farther north, so don't let your guard down!

Take Care.

David Aborn
North Chickamauga Creek Conservancy
Chattanooga, TN