** Michael Pr asked -

> So, what would be the advantages of this system of mass-roost, radiation
> from that site to forage areas? If it didn't confer some advantage, a smart
> animal like a crow wouldn't do it. I'm missing something obvious here. Help!
> Any ideas?

Get a copy of Berndt Heinrich's "Ravfens in Winter". He discusses this in some
length. Excellent book that should be required reading by all birders and
budding biologists.

- Jack



Jack Bowling
Prince George, BC
jcbowling at mindlink.bc.ca