The bander’s eye view: Flickers

After comparing data, the banding community identified a burning question: “Why do some eastern seaboard Yellow-shafted Flickers have orange, salmon pink or even red, major flight feathers in their wings and tails?” These birds could hardly be hybrids or intergrades because Yellow- and Red-shafted groups are only in contact during the breeding season in the Rocky Mountains, not here in Massachusetts. Also, because we note details of feather color and molt of the flight feathers after breeding, we were able to record that the same bird in later years might have either more or fewer reddish flight feathers among the normal yellow. In about 10% of more than 100 molting flickers at Manomet, reddish feathers were detected. Was diet the culprit?

To solve the mystery, we compared our flicker data with data from the Rouge River Bird Observatory in Michigan [side note: Julie Craves, who runs the Rouge River Bird Observatory and is a co-author of the paper mentioned below was a Manomet Bird Observatory in 1992.  She would have learned about molt recording in our lab. Our records show that she handled 156 birds in the Banding Lab that year.  19 Yellow-shafted Flickers were recorded in the lab in ’92, but no red feathers.] museum study skins from Canada’s Royal Alberta Museum, and academic feather analysts from universities in Pennsylvania and Massachusetts. In the analysis of our flicker feathers, the red pigment rhodoxanthin—derived only from introduced berry-bearing shrubs, mostly Bush Honeysuckles (Lonicera spp.) from Asia—was the cause of the change. In addition, flickers in molt seen in our banding lab grew only yellow feather shafts after the honeysuckle berries were gone for the season. Finally, older museum specimens from before the introduction of Bush Honeysuckles showed no red feathers.

Thanks to a team of experts working across North America the mystery was solved! To read the full paper published in The Auk, click here.

Birds are highly dependent on the foliage and plants around them. Every year, millions of migrant songbirds pass through the forests of the northeast on their way to southern lands. As they travel, they scour leaves and trees for food and eat the sugar-rich berries of native plants to fuel long-distance migrations.

We study birds for their uniqueness, but they also reveal something deeper about the world we live in. The data our banding lab collects improves our ability to understand the lives of migratory birds, and address long-term population changes and the effects of climate change.