Jan 29 2010
Here’s a bird who’s a natural for today’s anatomy lesson.
Not only is this bird showing off his namesake but you can see a V of gray-edged dark feathers below his rump that overlap like shingles on a roof. These are his upper tail coverts, the feathers on the top side of his body that cover his tail. The pink arrow is pointing to them.
Upper tail coverts are usually bland feathers shorter than the tail, but peacocks have overturned that rule. Their fancy “tails” are actually very long upper tail coverts that they raise during courtship display. When they do this, they reveal a relatively small tail.
While our yellow-rumped warbler is paused, let’s use him to review some earlier anatomy lessons.
Can you see his nape? It’s plain and gray compared to his mantle which has long dark stripes on a brown background. If you look closely you can see the scapulars on his right wing, edged in brown. They’re draped over his primary upper wing coverts whose feathers are edged in white.
This yellow-rumped warbler is in basic (i.e. winter) plumage and is posed in a way that hides the field marks on his sides and head that indicate his sex. If he’s a male, he will molt his brown feathers and become black and white in the spring – but he’ll always keep his bright yellow rump.
What a cooperative bird! Chuck Tague photographed him in Florida where yellow-rumped warblers are very common in winter.
(photo by Chuck Tague)