Wednesday, November 3, 2010

Catharus mug shots

In the field, spotted Catharus thrushes can sometimes be challenging to identify, especially when the bird is unwilling to allow more than a furtive glance through dense cover. Here at the Tortuguero CCC bird banding station in Costa Rica, these thrushes (especially Swainson's Thrush) are the bread and butter of the banding station this time of year. In the hand, they are surprisingly easy to identify.

I get lots of Swainson's Thrushes (I banded about 30 individuals of this species yesterday morning), some Gray-cheeked Thrushes, and an occasional Veery. Hermit Thrush doesn't come down this far, it winters in the southern and eastern United States, Mexico, Guatemala and western El Salvador. Bicknell's Thrush winters in the Greater Antilles.

At the top, a Swainson's Thrush (left) and Veery (right). Note the difference in tone color and eye ring.

Here, the same duo from above. Even then it is easy to tell which is which.

Here another duo. Our reference bird, the warmer, eye-ringed Swainson's Thrush in back, the colder Gray-cheeked Thrush in front.

Side by side, the differences between these three species are substantial, and immediately obvious.

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