National overview

Migration continued across the Eastern US in advance of the latest frontal boundary. Heaviest migration was apparent over northern Florida, throughout the Southeastern US, the Texas Gulf Coast and up the Pacific Coast of California. Migration was evident as far northwest as Oregon and Washington. Those areas immediately behind the front experienced little to no northbound movement, as these areas are typically under strong northwesterly wind and/or heavy precipitation. Interestingly, the radar did indicate some southbound movement over Wisconsin and northern Iowa suggesting a bit of reverse migration (see below for details).

Below are the radar loops from sunset last night through 5:00am (central time) this morning

Upper Midwest

Minnesota & Wisconsin

Frames are every 1/2 hour. click on the thumbnail to view the full-sized animation.

Things get really interesting when you look at the Wisconsin radar. By sunset last night the front had nearly passed to our southeast and light northwest winds ( < 10 mph) had built in over the state. In most cases I would expect no migration on a night like this, and yet all three radars indicated a light but clear movement of birds. These birds were not heading north, as would be expected in spring, but instead were heading back south. I confirmed these were birds by looking at the winds last night ( < 10 mph), and comparing it with the speed at which these objects were moving across the radar (> 20 mph). Since birds are the only airborne animals (along with bats) that can fly at speeds 10-20 mph faster than the prevailing winds, I have a high degree of confidence that this was indeed reverse migration.

So why would birds be doing this? It’s possible that birds who arrived into the region over the previous two nights found themselves in suboptimal habitat in terms of resources and/or cover. Birds expecting to find more open water and/or snow-free habitat (and in turn, more insects) may decide to head back south to find greater resource abundance and wait out the northward progression of true spring conditions. Either way this provides a great opportunity for birders to check out locations where they had high concentrations of birds over the last two days and see if those conditions still exist today.

Iowa & Illinois

Frames are every 1/2 hour. click on the thumbnail to view the full-sized animation.

Some reverse migration was also apparent over the Davenport radar early this morning, after the passage of the low pressure system. It looks to me from the radar imagery that most of that reverse movement was along the Mississippi river. The Chicago area was under heavy precipitation for most of the forecast period and therefore experienced little to no migration activity.

As always, woodcreeper.com depends on you to report your sightings and be our ‘eyes on the ground’, so please come back and give us an idea of how we’re doing predicting birding conditions in your neck of the woods.

Good Birding,

David

For migration updates in other regions check-

Michigan’s Upper Peninsula - The Northwoods BIRDAR by Max Henschell
New England - Tom Auer’s blog
Florida/SE - Badbirdz Reloaded by Angel and Mariel Abreu
PA/Ohio Valley - Nemesis Bird by Drew Weber
NW Ohio - Birding the Crane Creek by Kenn Kaufman
Pac NW - Birds Over Portland by Greg Haworth
Continental US - eBird BirdCast Forecast & Report by Team eBird