Christopher,

Saw your posting on tweeters about the Peregrine Falcon (Falco peregrinus)
harassing a Red-tailed Hawk (Buteo jamaicensis) at the University of
Washington campus.

Sorry for the delayed response, I'm on Digest mode.

Two (three?) weeks ago the adult female peregrine named "Freeway" returned
to her winter territory centered around the I-5 Ship Canal bridge for the
eighth time (she has fairly distinct plumage and a silver USFWS band on her
right leg). As you know the campus and Ship Canal bridge are within <2
kilometers distance of each other. Peregrine winter territories are defended
from other birds of prey. We see this in the downtown pair, we saw it in the
adult female who used to winter downtown before establishment of the nesting
territory. I have seen Freeway harass red-tails over UW campus several times
in past years. I'm willing to bet it was "Freeway" you saw, up to her usual
stuff.

In the past Freeway has had her caches of left-over food, stashed on beams
below the bridge or in the towers, pilfered by red-tails. This may explain
her particular dislike of red-tails and harassing them "all the way" over UW
campus. I put all the way in parenthesis since UW campus falls well within
Freeway's normal winter territory. Over the years we (FRG) have found it
extends from UW campus (including Husky Stadium) and the highest building in
the area, the SAFECO tower, all the way west along the Ship Canal to the
power towers west of the Aurora Bridge (by Falcon Research Group members
referred to as the R(ed) H(ook) B(rewery) towers. Last winter we once found
Freeway at the Grain Terminal just north of downtown along the waterfront;
in the past she's also been seen at Green Lake, to the NW. Probably these
last two sites are well outside her winter territory, although probably
within her winter home range.

When you drive the I-5 Ship Canal bridge, look at the power towers west of
the bridge. Freeway often perches in the top at the end of the horizontal
crossbars, practically sitting over traffic. Another typical behavior for
her as territory owner. Other peregrines use the bridge and towers,
attracted by the abundance of pigeons, but in my experience hardly ever act
like they own the place and sit prominently in the highest perches
available. All of them perch lower in the towers or beneath the bridge,
something Freeway also does.

Martin Muller, Seattle
MartinMuller at email.msn.com