Thursday, May 10, 2012

Migration Outlook May 11 - 13

Thursday, May 10:  This week has been characterized by high diversity and fairly good numbers of birds.  Weather conditions have not been right for massive arrivals of migrants, but decent numbers have been coming in anyway.  By now, 36 of the 37 likely species of warblers have been recorded in the area; at least one and probably two Kirtland's Warblers were near the east end of the Magee Marsh boardwalk on Wednesday, May 9.  Only Connecticut Warbler (typically a late May migrant) has not yet been found this season, to my knowledge. 

As of today, the mix of species is still shifting over from first-wave to second-wave migrants.  Yellow-rumped Warblers are still very common, and second-wave birds like Magnolia Warblers are nowhere near peak numbers yet.  I expect this to change over the next couple of days.  Tonight (Thursday night) the winds are almost calm, the sky is clear, and the radar indicates that many birds are migrating.  I think that on Friday morning we'll see noticeable turnover, possibly with fewer birds around than today.  However, Friday night the winds should be southerly to southwesterly all night, and even though they won't be associated with a major frontal system, I think that a lot of migrants will come in overnight.  Saturday morning, May 12, there should be diurnal migrants flying along the lake shore (flocks of Blue Jays, goldfinches, and others).  Early in the morning, many nocturnal migrants such as warblers should be moving along the lake shore as well, shifting location as they seek the best habitat in which to spend the day.  By midday Saturday there may be a small flight of hawks, although most of the migrant hawks have gone through already.

Saturday's birding should produce an excellent mix of migrant songbirds, with species such as Magnolia, Bay-breasted, Chestnut-sided, Blackburnian, and Cape May warblers becoming common, and the first real push of Blackpoll Warblers and American Redstarts.  All five of the expected brown thrushes should be around, plus most of the vireos, more flycatchers than earlier in the month, Lincoln's Sparrows, and others. Late on Saturday the wind is probably going to shift around toward the northwest, so many of Saturday's birds are likely to be present still on Sunday, although perhaps less concentrated near the lake shore.

Birders in the area the last couple of days have noticed many large swarms of tiny insects over the marshes and woods near the lake.  Over the Magee boardwalk, their swarms in some places were large enough to create a loud whining hum.  These insects are midges (family Chironomidae).  They are completely harmless, unable to bite or sting, and they are very important as a food source for migrant songbirds.  They represent another reason why the wooded areas among the western Lake Erie marshes are so valuable as stopover habitat for migrants!  If you happen to see and / or hear these swarms of midges, don't be alarmed; just be glad that the migrating birds will be able to fuel up for their next flight. 

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