Tuesday, November 20, 2007

Patterns of winter irruptives

First, the almost-winter-finch: Bohemian Waxwing. The first for the Cayuga Lake Basin was reported yesterday by Chris Wood and Tim Lenz. Chris's photos here (note his flickr name).

Matt Young the winter finch guru has posted some more notes on winter finch patterns reposted here with permission (thanks Matt!).

I'd be willing to bet the Bohemian Waxwing found near Long Pt. yesterdy is an early record for the basin.

And in a recent post someone had wondered about Pine Grosbeaks arriving in the Ithaca area before Bohemian Waxwing-- For those of you that don't know, I believe this has to do with origin of irruption. Bohemian Waxwing appear to have a more west to east trajectory, first showing up in numbers to the north in Maine. Birds appear to backfill in from Maine to NY. So, they head west from say Alberta to Maine/Nova Scotia and then backfill in from Maine to NY. Their core zone of appearence in NY is the northern 1/3 of the state from say Watertown to Champlain Valley and points north. During irruptive years they're often found in northern NY in mostly "pure" Bohemian flocks in Jan --usually only a few Cedars are found at all during such years in the winter in northern NY. Bohemian Waxwing is more a Jan bird in northern NY and more a late Feb-early April bird in Ithaca. Then from say Watertown to Syracuse across to Albany many mixed flocks appear and some smaller pure flocks of both species appear.

South of Syracuse we primarily find Cedar flocks with just a few to a handful of Bohemians. South of NY, any Bohemian is quite rare.

Pine Grosbeaks invade the state more from North to South (especially the Maritime ssp.) and from the NW to SE (the Canadian ssp.). So, during the rare years Pine Grosbeaks make it into the Ithaca it is not at all uncommon to find them before Bohemian Waxwings since Bohemians are usually not found in the "basin" until Feb. I believe there were a handful of nearly pure Bohemian flocks in the Ithaca area March 2002. I've also heard about Steve Kelling seeing a pure flock of 20-30 on Mt. Pleasant in Jan back in mid 90's?

Matt Young

No comments:

Post a Comment