Wednesday, February 5, 2014

butter butt

We only have a few more weeks of desolate winter to weather before the coming of vibrant spring. 

I find that by this time of the year, I long for color. The grays and browns of winter start to wear on me and sometimes just the briefest flashes excite.

Example: a species of warbler that spends its winter here in the valley, the yellow-rumped, spends it in its dingy winter plumage, that is except for its namesake bright "yellow rump."

Joy Baker recently captured one with her camera. And even though it is a ho-hum color, her photo (above) shows that its "butter butt" shines for all to see.

In a few weeks, Joy's warbler will migrate north to New England and the provinces of Canada where it nests. 

Breeding plumage Photo:wikimedia
It will also molt into its more dramatic breeding plumage (left), shedding its winter drab. But the yellow rump stays bright.

I understand why they molt into bland plumage to better blend into the dull winter background, and the intense contrasting colors of spring to attract a mate.

But here is the question: Nature is enormously practical, why keep the bright yellow rump in winter? To what purpose? Doesn't it make them more noticeable to predators like sharp-shinned and Cooper's hawks? 

To what advantage the butter on thy butt?

Thank you for the use of the photo, Joy.  


sarah in the woods said...

For happiness, and that's all.

Stephen Lyn Bales said...

Well now sarah of the woods, you may be correct. Seeing that yellow spot certainly makes me happy!