Friday, April 3, 2015

Wax on, wax off


This morning I watched a large flock of Cedar Waxwings (Bombycilla cedrorum) feeding on berries. 

It was intriguing to see how they foraged so closely to each other (see below)...although waxwings are known for being "social."  

I was also struck by how well their coloration the light and dark markings camouflaged them in the tree.  It was easy to lose track of individuals as their masks looked like the bark of the tree or shaded spots, and their pale bellies blended with views of the sky.


Here's another example (next image).  How many waxwings do you see?  You can click on the image for a larger version.  (Some of the birds are only partially in view.)


Below is another image with the birds that I found marked by yellow numbers.  Let me know if I missed any!



Waxwings are named for the red, wax-like droplets that develop on the secondary feathers:


You might have noticed that not all of the waxwings have "wax on their wings."  (See second photo of this post.)  The image below shows one waxwing with its wing lifted, making it easier to see the isolated red droplets at the tips of the feathers.  Birds with more red droplets are older, and tend to nest earlier in the season and have greater reproductive success, leading researchers to believe that the red markings have something to do with mate choice and social organization.  (Facts from The Birds of North America account by Witmer et al. 2014.)


Today I also noticed one bird with red markings at the tips of its yellow tail feathers:

 

Interestingly, I learned that there's only one breeding record for Cedar Waxwing in Sonoma County (in Kenwood in 2007).  In California, it's apparently rare for Cedar Waxwings to nest south of Del Norte and Humboldt counties.

Most Cedar Waxwings will leave this area during the next couple of months and then will return in the late summer or fall after nesting farther north.  So if you know of a berry patch nearby, enjoy the waxwings now while you can!

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