On a stroll through the park (and not seeing much beyond "the usual")
I was returning home along the "holloway" that runs parallel to
Federal Ave E in the along the southeastern side of the park.

A large number of crows were making their frantic mobbing calls in
tree (pine?). By the time I got there at noon there were 80+ in and
around the tree with a lot of head-down cawing. I suspected a raptor
and thought it was most likely to be a Cooper's Hawk (there have been
an adult and a juvenile COOPER'S HAWK active on Capitol Hill for the
past few months).

The crows pointed me in the right direction and I spotted through
binoculars a half-awake BARN OWL at the cut end of 6" diameter branch
in the pine(?) tree about 30 feet above ground. Without bins the owl
blends very nicely into the background (which suprised me for such a
light colored bird).

The crows took about 5 minutes to build up to their peak of 80+ birds
and a lot of noise. They kept that up for 10 minutes until a
significant fraction decided to leave (perhaps 30 to 40 birds). Over
the next 5 to 10 minutes the number of crows mobbing the owl dropped
to about 10 in the same tree with the noise decreasing sharply (at
the end just one crow cawing).

The tree in which the BARN OWL was perched/roosted is adjacent to a
yellow house and a wood chippings pile from the cleanups from the
recent storm. It is about 100m north of the stairs up to the holloway
from E Prospect.

Given the way he "rode out" the mob I suspect he may be there until
dusk and hunting becomes a possibility.
--
Kevin Purcell
kevinpurcell at pobox.com