National Overview
Storms resulting from a string of low pressure cells across the midsection of the U.S. delineated the northward boundary of heavy migration last night. As a result birds continued to move into South Texas behind the storms, and into the Midwest between them, but the Upper Midwest remained fairly quiet under northerly winds. The coastal Mid Atlantic received a well deserved shot in the arm last night as migrants streamed up from the Carolinas to Long Island, NY. Migration was also evident over Pennsylvania but failed to make it much farther north as conditions deteriorated latitudinally.
Below are the radar loops from sunset last night through 5:00am this morning
New Jersey (Mid Atlantic)
Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.
Moderate levels of migration were evident across the coastal Mid Atlantic last night with the heaviest movement over New Jersey. Looking at the velocity you can see a strong directional flight with birds heading SW->NE over the region. This bodes well for coastal migrant traps such as Cape May and Sandy Hook, as well as inland traps such as Garret Mountain (since there was also a good flight over PA, extending the migration cloud well out to the west). Thanks to the twittering habits of @tom_reed and @slrbrd (Sam Galick) we know that at least some of these migrants were waterfowl since as they added Black Scoter to the almost legendary “Steve Bauer’s Yard List” (Green Creek, NJ).
Wisconsin (Upper Midwest)
Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.
Winds over the Upper Midwest were not conducive to heavy migration and a quick review of the radar confirms this notion. As you can see, Milwaukee is back online (good) but judging from the radar last night no birds were moving overhead (bad). La Crosse shows some patterns which are less clear. Some reflectivity is apparent after sunset and but it’s quite diffuse and while the velocity doesn’t add up to bird migration it doesn’t completely rule it out either. I have to assume that La Crosse is inherently affected by aerial plankton (possibly insects coming off of the rivers in the evening) or that waterfowl get picked up more often because of the available habitat because I have yet to experience a night where La Crosse is completely devoid of a signal. Regardless, movement across the radar was generally E->W and the pattern is less consistent with migrating birds. Based also on the surrounding radars (not pictured) I’m going to assume this is not bird migration (or at least not to an appreciable degree). Expect conditions to remain consistent with the last few days with no big changes in either diversity or density. Expect birds that are present to move into more optimal foraging habitat which, in southern WI at least, is pretty much everywhere trees are present.
Good Birding,
David
One response to “Mixed migration as storms build throughout the U.S.”
I gleaned this from Sharon Reilly’s post on the Wisconsin birding listserve:
“Late this afternoon was able to stop by Devil’s Lake SP 4/3/2012 . FYI – the midges are erupting and the loons and osprey are back. Heard a golden-crowned kinglet. Very windy so the midges were lined-up along the lake edge. Expect more birds soon but it’s a bit worrisome with the freeze expected tomorrow night.”
Maybe the midge emergence explains the signal on the La Crosse radar?