An ornithological mystery has been solved! Puzzling red feathers have been popping up in eastern North America’s “yellow-shafted” population of Northern Flickers, but they aren’t due to genes borrowed from their “red-shafted” cousins to the west, according to a new study in The Auk: Ornithological Advances. Instead, the culprit is a pigment that the birds are ingesting in the berries of exotic honeysuckle plants.
The Northern Flicker comes in two varieties–the birds of the west have a salmon pink or orange tinge to the undersides of their wings, while the eastern birds are yellow. Where the two populations meet in the middle, they frequently hybridize, producing birds with a blend of both colors. For years, however, flickers far to the east of the hybrid zone have been popping up with red-orange wing feathers.
“At one point considered valuable wildlife habitat and widely disseminated, the naturalized Asian bush honeysuckles are now considered invasive and undesirable in many states. This is clearly not the last we have heard of aberrantly colored birds,” says Hudon. “The ready availability of a pigment that can alter the coloration of birds with carotenoids in their plumages could have major implications for mate selection if plumage coloration no longer signaled a bird’s body condition.”
“This is the pinnacle of a lengthy series of papers on the pigments deposited in primary feathers. Hudon et al. make use of the most up-to-date spectrometric and biochemical analyses to identify and quantify the pigments,” according to Alan Brush, an expert on feather color and retired University of Connecticut professor who was not involved with the study.
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