As discussed in recent posts by Tom Fiore, Angus Wilson, and others, early December can be an exciting time for finding unusual birds in the Northeast, and the upcoming CBC season is sure to feature many exciting discoveries.
The question of where our early winter avian novelties come from is surely fascinating. As long ago as the 1950s, Ludlow Griscom showed that a winter specimen of Yellow-breasted Chat from Massachusetts was actually an example of the western North American “Long-tailed” Chat (Icteria virens auricollis), not the nominate southeastern subspecies that is rare as a breeder even on Long Island. This is really neat when one considers that, although the vast majority of Chats winter deep in the tropics, a significant—and increasing—number are now wintering from Long Island to Nova Scotia. Thus, this question of connections between breeding origins and winter occurrences has been taken up by researchers investigating topics as disparate as how bird populations are responding to climate change and how vagrancy fits into the migratory ecology of birds. Juliette Goulet, a doctoral student at the College of Staten Island and the City University of New York, is studying some of these questions, using Gray Catbirds as a model. Unlike Chats, Summer Tanagers, and Rufous Hummingbirds, this species is a common breeder throughout New York State. Juliette would like to know if the increasing numbers of wintering catbirds in our region derive from local breeding populations, a variety of different breeding populations, or some specific breeding population other than our local one. It is possible that birds breeding, for instance, in the Upper Midwest, are colonizing a new wintering range in our region in response to environmental changes. One part of Juliette’s dissertation research involves using stable isotope analysis to determine the breeding origins of catbirds wintering in the Northeast. Anyone interested in these matters could greatly assist her in the following ways: 1. If you find a road-killed, window-killed, or cat-presented catbird between late November and early April, please contact either Juliette or me immediately so that we can arrange to salvage one to three tail feathers for analysis. 2. If you find catbirds wintering in places where banding is feasible, likewise notify us so that we might arrange to band the birds. By doing so, Juliette will be able to collect information concerning age and body weight, and also to collect a feather for isotopic analysis. We hold permits to band birds and collect feathers from the federal, NYS, and other regional state governments. If in doubt, please contact us! Shai Mitra Shaibal.Mitra AT csi.cuny.edu (note new email address) Juliette Goulet jgoulet AT me.com College of Staten Island Think green before you print this email. -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES Archives: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
