Migration: Recap of May 6-7, and outlook for May 8-11

Black-and-white Warbler at Metzger Marsh Wildlife Area, Ohio, May 2011. photo/Kenn Kaufman.

Late Saturday night, May 7: The last two days have been outstanding for numbers and variety of songbird migrants on the Lake Erie shoreline in n.w. Ohio. We had predicted that these would be very good days, but Friday turned out to be substantially bigger than I had expected. The BSBO main research site had one of its biggest days ever for number of birds banded (over 1000 individuals!), giving good backup to the field observers who had the impressions of large numbers. Saturday was also excellent, with numbers perhaps 70 percent of what had been present the day before, and continuing good variety.



At least 30 species of warblers were recorded on Friday May 6, and at least 27 on Saturday May 7. To a surprising extent, the migration was still dominated by early-season species – Palm, Yellow-rumped, Black-throated Green, Black-and-white, and Nashville Warblers, plus Northern Parulas (unusually common), White-throated Sparrows and a few others – the dominant species from the first wave. This suggests to me that the birds had been held up just a little south of us, and when conditions improved we got a major influx even without major winds. Of course, that means there are huge numbers of migrants still to come. Birds that will be a big part of the second wave, like Magnolia and Chestnut-sided warblers, are still present in only small numbers. They will pick up sometime soon.


Predictions: At 10 p.m. Saturday night the winds were very light and still southerly, but they are expected to shift to the northeast before morning, slowing down any potential bird movement. Sunday May 8 should have pleasant weather, and a decent percentage of today’s migrants should remain; I don’t expect a mass departure. With winds continuing mostly easterly through Monday, I expect a pattern of gradually declining numbers through Monday May 9. (Of course, at this season even a slow day should produce at least 20 species of warblers.) It still appears that there will be another big arrival of birds on either Tuesday or Wednesday – possibly both, but right now I would bet on Wednesday May 11 as the next major push of migrants. Hard to tell just how big it might be. The weather forecast maps are showing a major low-pressure system approaching from the west, setting up a big flow of air out of the south coming all the way up from the Gulf Coast, and my only questions have to do with timing: how soon will it be close enough to affect us? My guess at the moment is Wednesday, but I’ll try to update before then.


Short prediction: Good but with gradually decreasing numbers Sunday May 8 and Monday May 9. A big arrival happening Tuesday May 10 or much more likely on Wednesday May 11.


Notes for anyone coming into the area before then: A beautiful adult Tricolored Heron continues at Metzger Marsh, now present there for 2 weeks. A Marbled Godwit has been present for the last two days in a flooded field behind the Barnside Creamery, corner of Route 2 and Route 19, 1.5 miles east of BSBO. Prothonotary Warblers were seemingly a little late showing up in the area this year, but at least a couple of males are now establishing territories along the Magee Marsh boardwalk and they should remain through the season.