Carrol was at Bob Farmes Pool road at the Agassiz National Wildlife Refuge on Sunday, June 6, 2010. He noted that this great crested flycatcher had an exceptional amount of aberrant yellow plumage over its back and and a very yellow breast. Carrol said, "The bird was pecking persistently at a large timber wolf dropping in the middle of the road in order to remove a beakful of snowshoe hare fur which I assume it was using to line its nest. Recycling at its very best."
I love it. As if finding a flycatcher with excessive amounts of yellow wasn't cool enough, he ups the ante by mentioning that its gathering nesting material from wolf scat. Here are some photos of a great crested flycatcher that Mark and Roger got while banding birds at Mr. Neil's so you can see what it should look like:
Here's the back of a flycatcher--there's a bit of yellow edge along the wing feathers, but nothing like Carrol's photo above. Many people have heard great crested flycatchers, but may not see them. Here's what they sound like.
And here is the front of the flycatcher--note they do have some yellow on the belly, but nothing like what we see in Carrol's photo. I thought the photo was a perfect time to talk about an AWESOME book that came out this spring.
This is one of my favorite bird books to come out in the last year. It's by National Geographic and it's called Bird Coloration Geoffrey E. Hill. The book is a user friendly guide to the hows and whys of bird coloration. It uses illustrations and photos along with an engaging text to explain why that tanager is such an intense red.
They really went the extra mile with this book to make it approachable and interesting. This is a great book for birders of all levels--rom the great pop out tips for beginners to the hard core information like "psittacofulvin pigments."
I looked up yellow pigment to see if I could shed any light on the excessively yellow great crested flycatcher. On the flycatcher's back, it should have phaeomelanin--this creates the earth tone colors you see in birds. Birds can have intricate patterns of phaeomelanin in their feathers but since the flycatcher above has yellow on the back--it would appear that something went haywire in its genes and patches of its feathers are lacking phaeomelanin.
The book mentions that colors like orange, red and yellow in birds come from carotenoids. It mentions that birds with carotenoids tend to have patches of it on the body--like on the crown or breast and not intricate patterns (think about birds with red, yellow or orange--like orioles, cardinals, tanagers and goldfinches). "No bird shows an intricate within-feather pattern of red an yellow, a circumstance suggesting that fine control of carotenoid deposition in feathers is not possible. Most patterns are created by carotenoid pigmentation when entire feathers are either pigmented or not pigmented."
So, could the bird's genes have gone so haywire that some phaeomelnin is missing and replaced by carotenoids? We can't know for sure but it's fun to speculate on this bird.