Hi Rob and Bill,

If you haven't read any of Bernd Heinrich's books on ravens I highly recommend them (Ravens in Winter and Mind of the Raven). Bernd describes why ravens will recruit others to kills-they are young birds that are trespassing on an adult raven pair's territory and need "safety in numbers" to get to the resource. Of course he was perplexed at first why an individual bird would want to share with many more but better to share than not have any at all (by get chased off by a resident pair). Perhaps you have already read about this but it is fascinating work. I am guessing crows are doing this for some different reasons than ravens (the crows may all be related within a block) since ravens are more territorial. Aren't corvids cool?

Simone Lupson-Cook
Seattle, WA
Zingie at aol.com