A Pile of Intrigue

This past fall we had several northern flickers migrate to or through our backyard. While flickers are year-round residents here, we usually see an influx in the fall. Seeing multiple flickers land in the yard and start probing for insects is one of the joys of fall.

eBird map of yellow-shafted northern flicker for June and July (http://ebird.com/map)

eBird map of yellow-shafted northern flicker for October through December (http://ebird.com/map)

We also have a lot of hawks moving through in the fall and occasionally they will take a bird in the yard. One day we found this pile of feathers in the lawn, a sure sign someone, probably a Cooper's hawk, had taken a flicker and started removing the feathers. While sad that there is one less flicker around, this is the circle of life and it allows another bird to continue living.

 

It is quite interesting to see what must be the belly feathers with the dark spots on the ends and how loose and fluffy they are compared to the more commonly found flight feathers.

And speaking of flight feathers. There were several of those here too. What we found really interesting was that not all of them had the yellow-shaft that the local yellow-shafted race (https://www.allaboutbirds.org/guide/Northern_Flicker/id). There is a red-shafted race common in the western US but those have all red. In the field guides they will show intergrades where the two races mate but those tend to be orangeish in color. So what causes the mix and red and yellow?

A mix of red-shafted and yellow-shafted feathers from the same bird 

Some internet searching led us to an article by David Sibley in Bird Watching magazine where he talks about the various color forms of northern flickers. This mix of colors apparently stems from the birds eating non-native Asian honeysuckle berries while growing in the feathers that are red. The birds can process most carotenoids to make yellow (for the yellow-shafted) but they are unable to properly process something in the honeysuckle so it always produces red. 

Quite an interesting tidbit about these fascinating birds and another example of how non-native species can bring new chemicals and conditions into an ecosystem that the local populations aren't able to properly handle. At least this time, it seems to have a pretty neutral impact.

Note: it is illegal in the US to collect wild bird feathers. The above feathers were only brought together for the photographs.