An Intergrade Yellow-shafted/Red-shafted Flicker!
On the 27th of August, the 2015 fall banding crew captured one of these exciting specimens—causing a couple of our otherwise serious scientists to leap with excitement.
So what is so exciting about this intergrade species?
Because it may not be an intergrade after all.
Northern Flickers are a type of migrant woodpecker. There are two color-types found in North America, Yellow-shafted and Red-shafted. Yellow-shafted Flickers are found from the Rockies to the East Coast, while Red-shafted Flickers are native west of the Rockies. However, ornithologists have seen flickers, mostly in a narrow zone where the two color-types meet, with both red and yellow-shafted flight feathers. Many assume that this intergrade form is caused by a genetic mixture of the two.
An example of an Intergrade Yellow-shafted/Red-shafted Flicker at Manomet
Yet all the way on the East Coast, Manomet’s banders have found many Yellow-shafted Flickers with reddish pigmentation within their major wing
and tail feathers. According to our dataset, an astonishing 37.5% of our 168 presumed resident flickers (from 1966-2015) had at least one red feather.
While these genes could have been passed down through some serious east/west migration, Jocelyn Hudon, the Curator of Ornithology from the Royal Alberta Museum, and Robert Mulvihill, an ornithologist at the National Aviary, recently questioned whether these red feathers seen in flickers on the East Coast could have more to do with diet than genes.
Last fall, we caught 5 flickers in one net run, but none of them were intergrades.
Hudon and Mulvihill have been looking through our rich flicker dataset, consisting of over 900 individuals dating back to 1966. Although the findings are not conclusive yet, there is cause to believe that a concentrated diet of certain red berries, consumed as birds are molting and re-growing their feathers, could be contributing to unusually red feathers sometimes detected in flickers, Cedar Waxwings, Yellow-breasted Chats and Baltimore Orioles at Manomet.
Another major study on our property will provide an insight into how this phenomenon is occurring. For two years, Amanda Gallinat, a Ph.D. candidate from Boston University, has been visiting our property twice a week in the fall to see when and how long berries are available for birds and, through the careful analysis of any bird droppings left in our bird bags, who has been eating what.
With these data and a deeper dive into our own molt cards, we hope to pinpoint when flickers are growing each of their wing and tail feathers and how that timing corresponds with the local berry availability.
It’s a great story of how our detailed observations can contribute to a scientific discovery and a deeper understanding of the birds around us!