April 7, 2010
Dr. David Aborn

Dear Students:

Migrants, migrants everywhere! Here’s a look back:
The southerly winds all week have really been bringing in a lot of migrants. There are reports from all over the country of good numbers of migrating birds. People along the Texas coast have been seeing lots of Black-throated-green Warblers, as well as the first Worm-eating, Blue-winged, and Kentucky Warblers, Summer Tanagers, Scarlet Tanagers, Orchard Orioles, and Wood Thrushes. Along the Alabama coast, there were reports of lots of different vireos, along with good numbers of Ruby-throated Hummingbirds, and the first Blue Grosbeak of the season. Coastal Georgia had many Northern Parulas, while people in North Carolina reported lots of Blue-headed Vireos. Here in Tennessee, there have been lots of Blue-gray Gnatcatchers at my study site, along with the first White-eyed Vireo of the year. A birder up at Frozen Head State Park saw 38 (!) Black-throated-green Warblers, as well as the first Prairie Warbler.

The strong southerly winds have allowed many migrants to make a lot of progress northward. Pennsylvania and Ohio had their first Chimney Swifts, gnatcatchers, Yellow-throated Warblers, and Louisiana Waterthrushes. Missouri reported their first Northern Parulas and Hooded Warblers, while the first White-eyed Vireo was seen in Central Park, and Tree Swallows have made it as far north as Massachusetts!

Birders out West haven't been disappointed either. The southerly winds have brought plenty of migrants their way as well. Several places in New Mexico reported many Cave Swallows, along with White-throated Swifts, Western Kingbirds, the first Bell's Vireos, Lucy's Warblers, and Bullock's Orioles. The situation was similar in Arizona, with reports of Lucy's, Wilson's, and Yellow Warblers, along with Cassin's Kingbirds and Bullock's Orioles. An Orange-crowned Warbler was seen in Nevada as well. See? Not many people were disappointed!

What Does This Week’s Weather Mean for Migration?
You should be getting comfortable reading a weather map by now. Last week, I mentioned a front that might force migrants to land. Well, that front weakened and so didn't have much effect. This week is different. Take a look at the map:

  • A couple of strong storm systems are moving across the country. Over the next couple of days, those systems will bring storms and northerly winds to the central US and Gulf coast. That means migrants will be forced to land for a few days, so the fallout chances look good.
  • By the end of the week, the same thing will happen in the eastern part of the country. The winds farther west will have shifted to the south by that time, so birds should have good flying weather and could make it up through the Great Plains, Midwest, and maybe even the Great Lakes region.
  • Farther to the west, the storm systems have already cleared out, so the winds should shift to the south in another day or two. That will allow a new batch of migrants to come in, and other to make it farther north.

To give you an idea of what is in store, a birder from Alabama submitted a report from the Yucatan Peninsula in Mexico. This is the point from where many migrants take off to cross the Gulf of Mexico and reach the southern US. He reported large numbers of Blue Grosbeaks and Orchard Orioles, and while numbers were not as high, he also saw a dozen species of warblers. This could be a good week, and we are still early in migration!

David Aborn
North Chickamauga Creek Conservancy
Chattanooga, TN