Anatomy: Feathers wear out

Recently molted remiges of Black-legged Kittiwake (photo from Wikimedia Commons)

After nesting is over, what’s the next big item on a bird’s agenda?  

It molts.

Birds lose their old feathers and grow new ones because their feathers wear out. 

Shown here are four primary feathers (remiges) molted by a black-legged kittiwake.  It’s easy to see that these feathers are no longer in good shape for flight.  Their edges are not smooth.

Notice how eroded the white barbs are compared to the black ones.  That’s because pigment adds strength to the feather.  The darker the pigment, the stronger the feather.  For this reason many sea birds have black tips on their white flight feathers and some birds have completely black primary or secondary feathers.

Check out these images of a lesser black-backed gull, an American white pelican and snow geese, to name a few.

For more on feather wear and how it affects the appearance of shorebirds, see this very helpful blog (written from Malaysia).

(photo from Wikimedia Commons.  Click on the caption to see the original)

3 thoughts on “Anatomy: Feathers wear out

  1. I clicked on the Less black backed gull link above expecting just a picture and instead got a great love story! I “love” the March 9, 2009 “love conquers all” blog ! Thanks for linking to it for those of us new to your blog this year!

  2. Thank you for the feather lesson. I have learned a lot from your posts. Over the years I have collected feathers of different birds, and now I know why they molt.

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