The past several weeks we’ve experienced an unusually frequent series of storms with easterly winds and rain. Birding them has been interesting: we’ve watched the age distribution of Lesser Black-backed Gulls shift from older to younger from one storm to the next (full adults were 20/36 at RMSP on 13 April but 0/24 on 26 April); we’ve picked up some oddities (a very early Common Tern on 13 April, a Black-legged Kittiwake on 21 April, and a Black-headed Gull on the 24th); but mostly we’ve been enjoying an interesting start to the spring shorebird migration.
Since Pat and I began birding together in April 1999, our overall pattern of coverage has been fairly uniform; even this year, while restricting ourselves mostly to southwestern Suffolk County rather than ranging more widely from Staten Island to Rhode Island, we feel that we’ve obtained a good feel for the tempo and mode of the migration. One thing we’ve noticed over the years is a pattern of correlation among some of the scarcer migrant shorebirds. Our first spring together, 1999, is a good case in point: one or both of us recorded American Golden-Plover, Pectoral Sandpiper, Stilt Sandpiper, Ruff, and Red-necked Phalarope; Whimbrels were found in better than usual numbers by others. Furthermore, it was a good spring for Lesser yellowlegs—a more numerous species but one that shares habitat preferences with most of the species just named and like them is much more numerous in fall than spring. Apart from Lesser Yellowlegs, these species are scarce enough in spring that Pat and I tend to detect them during ca. 30-50% of springs, in the course of our habitual field work (Ruff in 6/20 springs through 2019, with hope remaining in 2020). Their apparent co-occurrence in “good springs” and mutual absence in “bad springs” has been a topic of discussion: assuming it’s genuine and not an artifact of small samples, is it driven by year to year variation in habitat conditions or by variation in weather and migration dynamics? April 2020 has been a very good spring for this cohort so far, and probably my best ever for Lesser Yellowlegs (a conservative estimate of 50 at Captree Island on 24 April is an exceptional number for spring on LI). In discussing this with Doug Gochfeld the other day, he noted that all of these species undertake long flights northward and even northeastward over our region, making them prone to grounding by easterly storms. I agree with this interpretation, and note further that other rare-in-spring shorebird species, whose spring migrations from southeastern north America are oriented sharply westward rather than northward, have been absent this year: Black-necked Stilt, American Avocet, Marbled Godwit, Western Willet, Long-billed Dowitcher, Western Sandpiper, and Wilson’s Phalarope. Shai Mitra Bay Shore -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME.htm http://www.NortheastBirding.com/NYSbirdsRULES.htm http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birding.aba.org/maillist/NY01 Please submit your observations to eBird: http://ebird.org/content/ebird/ --
