Feathers That Change Colors

Monday, I read a post on Birdfreak about Cedar Waxwings. Rick Wright, who writes Aimopila Adventures added a comment with a link to an ABA article called Tricks Exotic Shrubs Do - When Baltimore Orioles Stop Being Orange by Tom Flinn, Jocelyn Hudon and Dan Derbyshire. The article is from Birding Magazine in the September/October of 2007 issue. This post is about the article.

Balimore Oriole - Photo by birdfreak.com

In Toronto,Ontario there is a research station for birds. In 2005 a Baltimore Oriole that was banded had red feathers instead of orange or yellow. In 2006 more red Baltimore Orioles were found. They didn’t know why this was.

They had a theory it was because of their diet. There are yellow and red pigments found in plants called carotenoid pigments when birds eat certain foods it can change colors of there feathers. In the 1980s a red carotenoid called rhodoxanthin was found to be what made some Cedar Waxwings yellow tail tips turned orange.

Berries of introduced bushes were found to have this carotenoid. The birds have to eat this during the time there growing feathers to turn different colors. The introduced honey suckles were thought to be good wild life habitats in 2005 there was a lot of these berries around. Another bird that had orange pigment were ther should have been yellow. Birders should report different colored birds to there local bird club or state birding association to help track if it’s spreading.

Cedar Waxwing - photo by Birdfreak