It’s been a head-scratcher for quite some time.  What’s with the yellow-shafted Northern Flickers in the eastern U.S. bearing some orange feathers? (As in the photo above, courtesy of C. Hansen)  The birds in question weren’t anywhere near the mid-continental hybridization zone where they could fraternize with their western red-shafted brethren.

New research in The Auk: Ornithological Advances appears to have zeroed in on the culprit. During their fall molting period, this population of Flickers has become fond of feasting on the ripened honeysuckle berries. In particular, the birds are picking up a pigment called rhodoxanthin from two invasive varieties of honeysuckle, as revealed through spectrophotometry and chromatography.

In a press release, lead author Jocelyn Hudon from the Royal Alberta Museum commented, “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.” Further, said 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.”

Written by Meredith Mann
The lowly Red-winged Blackbirds in suburban New York triggered Meredith Mann's interest in birds. Five years later, she's explored some of the the USA's coolest hotspots, from Plum Island in Massachusetts to the Magic Hedge in Chicago to the deserts of Fallon, Nevada. She recently migrated from the Windy City (where she proudly served as a Chicago Bird Collision Monitor, rescuing migrants from skyscrapers and sidewalks) to Philadelphia, where she plans to find new editing and writing gigs; keep up her cool-finds chronicle, Blog5B; and discover which cheesesteak really is the best. And she will accept any and all invitations to bird Cape May, NJ.