Molting and Bird of the Week Number 5

Five males and one female in flight

Female

Bird feathers are made of a substance very similar to your fingernails. Feathers are constantly wearing out and must be replaced and most birds are constantly replacing some feathers and this process is known as molting. Molting occurs in response to a mixture of hormonal changes brought about by seasonal changes. The entire process is complex and many questions remain regarding how the process is controlled. It takes a lot of energy to build new feathers. Molting is, therefore, often timed to coincide with periods of less strenuous demands, such as after nesting or just before migration.

When Do Birds Molt?
Most birds molt but once per year. Several, though have two molts every year. Some birds experience more wear and tear on their feathers - whether it is from long migrations or foraging through trees and brush - and require that extra molt to keep their feathers in shape.

As far as the actual timing of the molt, there is much variation from one species to another, and even within individual species. The exact dynamics and mechanics of the process are still not fully known; what is known is that molting does tax a bird’s energy. Therefore, it always takes place during a relatively uneventful time of the year.

Ducks go through their first molt of the year in early summer. Male ducks, or drakes, molt first. Females, or hens, molt later, when their ducklings are older. Many times, drakes get together in large groups to molt. They pick a safe place to stay, usually a large wetland. Molting is a dangerous time for ducks. They can't fly while their new wing feathers are growing in. So, molting ducks spend most of their time hiding in tall grass or floating out in deeper waters.

So, this brings us to the bird of the week. Some clues are that this is a sea duck and they do not range in Oregon. I went on a pelagic trip out into the Bay of Fundy off the coast of New Brunswick, Canada this past week and we came across several rafts of these ducks. This time of year the males and females separate and we came across some rafts of each. The males had already molted and were flying. The females were still in molt so they could not fly, and as the boat approached  they had to swim really fast to get away from us. The video is a bit shakier than usual due to the movement of the boat but you can see the birds fairly well.   It was an awesome site to see them.

http://youtu.be/NnGvz-Z0s0Q