Apr 30 2010
We’ve moved down the underside of the bird, past the belly and brood patch and are almost at the tail where we find… undertail coverts.
Undertail coverts are the feathers that smooth the transition between belly and tail. On most birds they’re the same color as the tail (see magpies) or the belly (as in most birds).
Gray catbirds are an exception that proves the rule. The entire catbird is gray except for his rufous undertail coverts. They’re so noticable that I didn’t even draw an arrow to point them out.
And, good news! You’ll be able to see this for yourself because gray catbirds have just returned from their wintering grounds in Central America. Yesterday I saw my first of 2010 in Schenley Park.
(photo by Alan Vernon, from Wikimedia, Creative Commons license. Click on the photo to see the original.)