Sunday, April 29, 2012

Migration Outlook April 30 - May 4: Prepare to call in sick

Northern Parula at Magee Marsh.  One of the many species likely to be seen the latter part of this week.  Photo by Kenn Kaufman.

April 29, 2012: Things have been slow for the last several days, with unfavorable winds, cooler temperatures, and some rain all acting against the arrival of migrants. Some birds have been moving anyway, despite the conditions; for example, down in central Ohio, a “fallout” of migrating Willets was noted yesterday, and scattered individuals of many migrant species have shown up near the lake shore. But things are about to change in a big way, with a major arrival of migrants expected this week.

The exact timing of things is still looking a bit tricky. I don’t expect many new birds on Monday, April 30, because winds will be northeasterly during the first part of Sunday night and easterly (with rain) later. During the day Monday, winds are supposed to shift to southeasterly and then southerly, and stay that way all day and into the evening. Then late in the evening Monday, winds are supposed to swing back around to the west and then the northwest. We’ll probably see some more diurnal migrants during the day (swallows, goldfinches, jays, shorebirds, maybe a few hawks), and some migrants may come in during the night Monday night, since there are many migrants just a short distance south of here in central Ohio. But Monday’s southerly winds are not a part of a major weather system, so I don’t expect Tuesday’s arrival to be huge.

However – Wednesday, Thursday, and Friday, May 2, 3, and 4, look like they have great potential. Winds will shift back to the southeasterly or southerly sometime on Tuesday, and this time they’ll be associated with an air flow coming all the way up from the Gulf of Mexico, so it looks like a good setup to bring in a major flight. I can’t tell whether the bigger day will be Wednesday or Thursday, but considering how many birds must be dammed up to the south of us, Wednesday would be a good bet. Both days should be good, with Friday at least fairly good also. There should be many, many migrant songbirds in the woods close to the lake, and probably a good hawk flight developing by midday Wednesday.

I talked to Mark Shieldcastle, BSBO’s Research Director, and he said that at this point it’s hard to say whether this next big flight will be more like the end of the “first wave” or the beginning of the “second wave.” In other words, we could see a flood of Yellow-rumped and Palm warblers and White-throated Sparrows, with a generous scattering of singles of other species, or we could see an overall increase in variety, with numbers of many species. Or it could morph from the first wave to the second between Wednesday and Friday. Either way, if you can get out to the lake shore migrant traps during the latter part of the week, I’d recommend it. You might want to call in sick at work or school on Wednesday – serious case of the bird flu! And if you can’t get out until the weekend, that should be good too, with loads of recently-arrived birds in the woodlots.

For more information on the timing of major “waves” of migrants, as worked out by Mark Shieldcastle from BSBO research, see this link:

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