Prince Edward Island (Canada) is hosting its 3rd ever Black Vulture for the past week or so.
http://www.surfbirds.com/cgi-bin/gallery/display.cgi?gallery=gallery10 Mike Cooper Ridge, LI, NY ----- Original Message ----- From: Kevin J. McGowan To: NYSBirds Sent: Wednesday, March 24, 2010 10:26 PM Subject: RE: [nysbirds-l] Brooklyn BLVUs From: [email protected] [mailto:[email protected]] On Behalf Of Angus Wilson Sent: Wednesday, March 24, 2010 8:13 PM To: NYSBirds Subject: Re: [nysbirds-l] Brooklyn BLVUs . The Times They are A-Changin': This is an exciting time for students of bird demography, what with Common Raven's building nests in Queens (unimaginable a few years ago), and Sandhill Cranes now a frequent sight in much of the state. Maybe Black Vultures will continue to expand and nest on Long Island also? The perennially question to ponder is why these changes are happening. At a recent Queens County Bird Club meeting somebody suggested the expansion of Common Raven into low-lying areas might be to fill a niche created by the effects of West Nile Virus on American Crow populations. I don't know if there is data to support this, but the idea is an interesting one. Perhaps vultures would also benefit from the increased availability of carrion (e.g. road kill) that isn't being snapped up right away by a super abundance of crows? Interesting things to ponder. But it is appropriate to point out that Common Raven has undergone a HUGE range expansion in New York (and elsewhere) in the last 20 years, as evidenced by the recent NY breeding bird atlas data, well before the appearance of West Nile Virus (WNV). The raven went from being a "wilderness" specialist to being present in 35% of the blocks in the state. It was missing only from the lowlands of the Ontario plain and the coastal regions. I believe that in the raven species account I suggested that it would soon reach those areas too. The raven trend is bigger than New York, occurring before WNV, and in areas that were not really affected by the disease. Not to say that WNV couldn't play a role, but ravens don't seem to have much regard for crows anyway, pretty much doing whatever they damned well please. Fish Crows, on the other hand, might be taking advantage of the American Crow die-back. They seem to do pretty well in areas with American Crows, but they definitely are submissive and might be kept out of potential breeding areas that the WNV effect would open up to them. (Fish Crows are only half as susceptible to WNV as American Crows.) Black Vultures also have been increasing in NY for a while (not present at all in the 1980-85 atlas). But as the Atlas species account (ahem, also written by me) points out, they have not really expanded out of the rocky southeastern part of the state since moving into there. Despite some criticism (!), in the Atlas accounts that I wrote I attempted to speculate on what past trends might mean for future distribution patterns. Black Vulture was a toss up. Its history indicated that it should continue spreading, and its wide habitat tolerance and huge distribution outside the US would suggest that it should be capable of inhabiting the entire state. And yet, after it appeared here it never seemed to go outside the realm of the rock-slide caves of the Catskills and lower Hudson Valley. It could, it should, but will it? For anyone who thinks that bird distributions are static and well known, PLEASE go buy a copy of The Second Atlas of Breeding Birds in New York State (Cornell University Press). (And I do not get any royalties or kickbacks from shilling this book either. It's just a great resource, IMHO.) Kevin **************************************************** Ithaca, NY 14850 [email protected] http://birds.cornell.edu/crows/ ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.437 / Virus Database: 271.1.1/2768 - Release Date: 03/24/10 19:33:00 -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ --
