Monday, April 13, 2009

The Turkey Vulture and Global Warming

On my way to a friend's cottage at White Lake, Ontario, I drove by this field where I spotted a crow and several turkey vultures [Cathartes aura] huddled around this dark object. By the time I opened the car window and had the camera ready the crow had flown away. These vultures were feeding on the carcass of a fairly large raccoon that the right-most vulture, in the picture, is standing on.

My first bird book, Birds of North America, Robbins, Bruun, and Zim, (1966) showed the range of the Turkey Vulture to be no farther north than a latitude of the middle of Lake Erie or about 400 km (250 mi.) south of here. As a youth and active birdwatcher back in the 60's and 70's I had never witnessed a Turkey Vulture anywhere in the area around Montreal where I grew up. The newer bird books -- and I referred to four; Stokes, Royal Ontario Museum, Kaufman and Sibley -- consistently show the Turkey Vulture range is now well north of North Bay, Ontario to a point over 200 km (125 mi.) north of here. I have personally seen them as far north as Otter Lake, Quebec on one of my drives there. I would say that this is real evidence of global temperature change wouldn't you say?


Anonymous said...

Pieter - We were just talking about the turkey vulture here outside Milwaukee a few days ago as we have seen many sailing along the ridge in front of my parent's home. "A Field Guide to the Birds (Roger Tory Peterson), 1980 edition, shows the Turkey Vulture on map M176. The breeding range extends nearly as far north as Ottawa (north of New York state), with a note that "actual breeding range in north (is) poorly known"

When I as growing up here outside Milwaukee in the 1960's, the turkey vulture was generally unknown. Since my parent's were birders, I assume they would have observed it had it been here. It has been frequently noted since the early 1980's. If Peterson is right, and there is no reason to doubt him, the Turkey Vulture must have been breeding as far north as north central Wisconsin in the mid-to-late 1970's for it to be noted in a book published in 1980.

I don't know what this implies about global warming.

P.M. Leenhouts

Woodlot_Manager said...

Peter - there is an undoubted change in the geographic pattern of the bird, just from personal observation, as there is with others such as the cardinal, another bird I never ever saw in my early birding days in Montreal. There has got to be some sort of a change going on.