Hi friends! Sorry I disappeared for a bit. Being a second-time college student and full-time music teacher, I am currently in the midst of finals and concert season, so it’s been pretty hectic around here. I’m hoping to be back to writing more frequently in the next few days.
Instead of doing the normal Woodpecker Wednesday profile post, I wanted to share an interesting woodpecker study. There was a woodpecker mystery that was recently solved by scientists. The mystery: red feathers in Yellow-shafted Northern Flickers. The answer was not what scientists were expecting.
The Northern Flicker is the most abundant woodpecker in North America. Although pretty common, they are probably the most unusual of woodpeckers. They mainly feed on the ground on ants, are weak tree excavators, and even roost in trees less than other woodpeckers. Another unique feature is their intricate plumage, which is brown and tan or light peach, with black belly spots and a “zebra-back”.
When John Jame Audubon first saw Northern Flickers in 1843 at Yellowstone, Wyoming he was puzzled. He saw five Northern Flickers that all varied dramatically in plumage color. Some were red, some were yellow, and other were in between. He didn’t know it at the time, but he was in what is now considered “the hybrid zone”.
There are two subspecies of Northern Flickers: the “Red-shafted” Flicker of the west and the “Yellow-shafted” Flicker of the East. They frequently hybridize in the Great Plains region of the United States, south to Texas and north to Canada. This hybrid zone is at least 4,000 years old. Unless you live in the hybrid zone, you are most likely to see either one subspecies or the other.
Over a century later, scientist were puzzled one again about Flicker plumage. Starting the the 1960s, some biologists began to notice that there were Flickers over a 1,000 miles east of the hybrid zone with red feathers. But there weren’t quite as bright as the western “red-shafted” plumage, they were more of a copper color. Some ornithologists speculated that the color was being cause by genes from the red-shafted being spread to the yellow-shafted population. Something wasn’t quite right with that explanation though, so studies continued.
But now the mystery is solved! A recent study published on October 12, 2016 in The Auk revealed what was causing the color change. And it turns out hybridization has nothing to do with it.
The answer: honeysuckle berries.
Red-shafted Flickers have red feathers because of 4-keto-carotenoids, a type of pigment. The “red” Yellow-shafted Flickers get their color from a pigment called rhodoxanthin. Rhodoxanthin is rare in the wild and only found in certain plants. By eating berries from honeysuckle plants, particularly the Morrow’s, Tartarin, and their hybrid Bell’s honeysuckles, they are ingesting this pigment. These “red-yellow” Flickers are eating this food source around when they molt and acquire new plumage.
So why did it take scientist so long to solve this mystery? The Northern Flicker’s diet consists heavily of ants and other insects. Since berries is a smaller portion of their diet, the pigment they are eating is usually not as obvious, so it took scientists a longer time to notice.
Although this mystery is solved for the moment, there are so many other ornithological enigmas to the study (how about the mystery of the Ivory-billed Woodpecker?). But that’s the great thing about ornithology and other biological sciences: there are so many fascinating and exciting discoveries just waiting to be found.
If you want to read the actual study you can read it here:
What kind of Northern Flickers do you see? Tell me about them in the comments.