Wednesday, November 10, 2010

One year old Cedar Waxwing

Cedar WaxwingCedar Waxwing, Forest Grove, Oregon on 21 October 2010 by Greg Gillson.


One final post on the many Cedar Waxwings I photographed in a hawthorn tree in October.

Post 1 showed 2 views of a waxwing feeding on hawthorn berries.

Post 2 discussed the molt and aging of this same adult bird.

Post 3 talked about an juvenile waxwing and discussed the waxwing's first description to science.

Today's post goes back to molt.

Perhaps after reading Post 2 you can see the patchy back plumage on this bird and discern a couple of pin feathers in sheaths on the cheek of this bird. Most obvious are the outer tail feathers that are still growing in. So this bird is undergoing a full prebasic molt into its first definitive basic plumage.

Why can we say this bird is attaining its first fully adult-like plumage?

If you look at the wings you will see some fresh dark inner primaries, and some very faded, worn, brown primaries. Those brown primaries are the remnants of juvenile plumage, the first (non-down) feathers this bird ever grew. Those tattered wing feathers are now over a year old. And that is the age of this bird--perhaps 16 months old. Once those feathers in the wing and tail are fully replaced and grown, probably before the end of November, it will no longer be possible to tell how old this bird is by looking at its plumage.

Here is a link that will bring up all my blog posts having to deal with molt.