Sunday, February 24, 2013

Chick-a dee-tails

Black-capped Chickadee in Massachusetts on 24 February 2013


Although Black-capped Chickadees are common songbirds across much of North America, I tried to find a few fun details that you might not be as familiar with:

- Males and females are generally indistinguishable, but males tend to have longer wings and tails, deeper blacks, brighter whites, and broader black bibs.

- Most of their flights are apparently less than 15 meters (49 feet) long.  They tend to avoid crossing large open gaps.  I'll admit, I haven't ever thought of estimating chickadee flight distances myself (have you?), but it would be interesting to see if this measurement generally holds true!

- Individuals tend to join winter flocks and stay within the same flock throughout the winter.  They may also re-associate with the same flock in subsequent winters.

- Within winter flocks, there is a linear social dominance hierarchy — males tend to dominate over females and older birds tend to dominate over younger birds.

- Black-capped Chickadees embed information about predators in their calls — if all you've thought you were hearing was a simple chick-a-dee call, you might want to listen more closely the next time.  They'll call more often and add more "dee" notes for smaller, more threatening predators.  And they'll respond more quickly and call more frequently for predators that are closer rather than further away.

(Facts above from Birds of North America account by Foote et al. 2010.)
 

[Black-capped Chickadees aren't common in California.  I'm still new enough to The Golden State that I'm not totally familiar with their status in the 3rd largest of the U.S. states, but it looks like they only occur regularly in the northwest corner of California, primarily in Del Norte and Siskiyou counties (edging into Humboldt and Trinity counties).]

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