Coming soon: Christmas Bird Counts (and some southerly transplants)

Dr. Thomas T. Barnes / U.S. Fish and Wildlife Service

Seen one of these guys recently? For you non-birders, it’s a purple finch. And, according to Earth Gauge, your chances of seeing one of them in southern New England this time of year are far better now than they were a few decades ago, thanks to climate change.

Warmer winter temperatures are allowing the Purple Finch to winter 433 miles farther north than it did in the 1960s.

Here’s what that looks like in graphic format:

And purple finches aren’t alone:

Between 1966 and 2005, significant northward movement of 177 out of 305 observed species was documented. Not all species moved north and a few may be wintering a little farther south, but the general trend has been an average northward movement of 35 miles. More than 60 species are now wintering at least 100 miles farther north than they did in the 1960s.

Just how do we know all this? Well, one big source of information on the winter habits of birds are the Audubon’s yearly Christmas Bird Counts. For over one hundred years, the Audubon Society has been tapping into the enthusiasm of bird watchers to accomplish what scientists could never hope to do on their own – compile a comprehensive census of bird populations from the Arctic to the tip of South America in a tight, three-week window. Audubon estimates that over 50,000 people participate in more than 2,000 local counts. The enormous geographic scope of the Christmas Bird Counts and their annual repetition make the resulting data ideal for picking out long-term and large-scale trends … like climate change impacts. It’s citizen science at its best.

The counting period for the 2011 count begins tomorrow, December 14th, and ends January 5th. If you’re interested in joining the effort, there are dozens of opportunities around New England (four on Cape Cod and one each on Martha’s Vineyard and Nantucket) and, obviously, hundreds nationwide.