Rolan:
There's still plenty to be learned about crow roosts and my answers are
mostly based on observations and studies in the Seattle area over the last
few years - I'll be interested to see if there are other replies as well
(I get the digest).


My questions are: What is the usual size of a crow roost?

In this area, from the 100's into the 1000's - counts at the Foster Island
roost at the Arboretum have been above 10,000 in wintertime. I have heard
of roosts in the Midwest that have hundreds of thousands of crows.

Are they permanant? Seasonal?

Most crows seem to go to one of the big roosts between October and March.
>From April to July/August breeding crows and their young tend to stay on
their territories. However, some (presumably) non-breeding crows go to
the same big roosts year-round - counts at Foster Island in the summer are
in the hundreds. I have noticed some smaller, possibly temporary roosts
in September/October before all the crows start going to the big roosts.

Why were they so low here Sunday? Was weather a factor?

I have definitely noticed crows flying closer to the ground if they're
going into the wind. Don't know about other weather factors.



> Rolan Nelson
> Burley, WA
> rnbuffle at yahoo.com
>
>

-John
University of Washington, Seattle