This is an entry from my blog, www.BirdmanofLauderdale.com . I'm posting it here because I'd really like to know if anyone else has an idea of what's happening to these birds, whether my theory of shrike strikes is bogus!
I think it was in October that I first noticed a black-capped chickadee with an odd haircut. It had a fringe of feathers at the back of the head, like one of the Three Stooges, and then short “hair” on the top and fairly normal length feathers above the eyes. Odd. I wondered if this was a molt issue, a disease, a mite infestation or the result of bullying by its peers (or rather, superiors). Then, last week we had a northern shrike in the yard. As I checked it out with the binocs, I noticed the body of a bird in the snow below it. The shrike bent down to pick up its kill by the back of the neck: a very limp black-capped chickadee. It wasn’t the one with the odd “haircut.” The shrike flew off with the chickadee in its bill. And just today, I saw a white-throated sparrow with a very similar crew cut…very short feathers on the top of its head but normal looking toward the back of its head and neck. I’ve read that the shrike kills its prey by whacking it on the back of the neck, severing the spinal cord. Could these modified head feather styles be the result of shrike near misses? Hitting the top of the head instead of the back of the neck? I’m not sure such a strike would cause a flat spot on the entire cap of the head. Mysterious. So, I’m left with a puzzle. Thanks for your comments, Clay Christensen ________________________ The Birdman of Lauderdale ---- Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net Archives: http://lists.umn.edu/archives/mou-net.html
