Tuesday, July 11, 2006

Chickadees, Titmice, and DNA

The current issue of Birding magazine has some interesting notes about recent research on chickadees, titmice, and other members of the Paridae family. (The report in Birding summarizes a study published last year in The Auk.) Researchers determined that the genus Parus, which used to contain all chickadees, titmice, and related species, should in fact be broken into multiple genera. The suggested division includes Poecile (chickadees) and Baeolophus (titmice) in North America. Eurasian and African tits are now divided into Parus, Lophanes, Periparus, and Cyanistes. The split of New World chickadees and titmice into the Poecile and Baeolophus genera is not new; the AOU recognized the split in 1998.

For North American birders, the results regarding chickadees are intriguing. Though the black-capped chickadee and carolina chickadee interbreed and are similar enough in appearance to make identification difficult, they are not as closely related as one might think. Instead, black-capped is more closely related to the mountain chickadee. Among carolina chickadees, there are significant genetic differences between the two subspecies, the eastern extimus and the carolinensis subspecies in Louisiana. Whether that would be enough to call for a species split is not addressed in the Birding summary.

1 comment:

Peter Vankevich said...

One of the ornithologists noted in this article is Beth Slikas, a former President of the DC Audubon Society! She took on these duties while doing research at the National Zoo. One of my favorite birding trips sponsored by the chapter occurred during her tenure. It was the great Chickadee quest that took place on the C&O Canal in March when chickadees were singing. We started at Noland's Ferry in Frederick County and observed and listened to the chickadees all deemed to be Carolinas. The next stop was Hancock, MD around mile 125 in Washington County. Interestingly, many of the chickadees at this stop had a three-note song, unlike the 4-notes of the Carolina Chickadee and the 2-notes of the Black-Capped Chickadee. Finally, we ended up in Little Orleans, Allegany County where the chickadees had 2-note songs. If I recall, these are the Appalachian race which are a bit smaller and drabber than the Black-cappeds farther north.
Peter Vankevich