April 14, 2010
Dr. David Aborn

Dear Students:

Well, the calendar says it is a different week, but the migration report is similar to last week's. The front I talked about weakened, so there weren't any fallouts. The winds quickly shifted back to the south, which allowed a steady stream of migrants to move across the country. Like last week, there was a good diversity of species, and there were some that were seen in high numbers. New arrivals in Texas included Yellow Warblers, Yellow-billed Cuckoos, and Rose-breasted Grosbeaks. Birders in Mississippi reported their first grosbeaks as well, along with the first Chestnut-sided Warbler, and many Orchard Orioles and Indigo Buntings. People in Alabama saw their first cuckoos and Wood Thrushes, as well as high numbers of White-eyed Vireos, Orchard Orioles, and Northern Parulas.

New arrivals at my study site over the past week include Prairie Warblers, Red-eyed Vireos, and a Scarlet Tanager. I also awoke this morning to the song of the first Wood Thrush; a pretty nice alarm clock if I do say so myself!

The southerly winds have been pushing migrants ever northward. Ohio reported their first Northern Parulas and Black-throated-green Warblers, along with increasing numbers of Yellow-throated Warblers. Folks in Illinois saw their first Northern Rough-winged Swallows, while birders in Missouri were treated to their first Chestnut-sided Warblers. Birders in Syracuse, New York had their first Louisiana Waterthrushes, Blue-gray Gnatcatchers, and Blue-headed Vireos, and a Baltimore Oriole was seen in New York City. The most northerly migrant sighting I received was a White-eyed Vireo seen all the way up in Massachusetts.

The West did pretty well, too. Southern California birders reported good numbers of Yellow-breasted Chats and Black-headed Grosbeaks, along with Black-throated-gray Warblers, Nashville Warblers, and Wilson's Warblers. Warblers were also the birds of the week in New Mexico and southeastern Arizona. As in the East, good tail winds helped some migrants get pretty far north, as large numbers of Vaux's Swifts were seen in Oregon.

What Does This Week’s Weather Mean for Migration?
So how does this week look? OK, you know the drill! Take a look at the weather map, and what do you see?

  • You got it; another cold front is moving across the country. It does not have
    much rain with it, but some good northerly winds are behind it. (Temperatures here in Chattanooga are expected to go from the mid-80's now, to the low 70's over the weekend). That should be enough to slow migrants down. In the Midwest and Gulf Coast, this should this take place during the middle and end of the week, while it will hit the eastern US this weekend.
  • Since the front has already made it through the West and Southwest, winds should shift back to the south in another day or two, allowing the next group of migrants to arrive from the tropics.

There is a lot going on, and the peak of migration for some of you is only a week or two away! For others, your fun is just beginning. Either way, make sure you get out and enjoy it!

David Aborn
North Chickamauga Creek Conservancy
Chattanooga, TN