Subject: Bird Use at the Aurora Bridge
Date: Nov 24 11:04:03 1999
From: Scuderi, Michael R NWS - Michael.R.Scuderi at NWS02.usace.army.mil


Hi Tweets,

I received three replies for our inquiry concerning peregrine use at the
Aurora Bridge in relation to the proposal to light the bridge. As a point of
clarification, the proposal before the Corps is for permanent lighting. The
information provided in the replies will be used in the permit decision.
As promised, I am providing copies of the messages for your information
(below). I am trying to do some searches of the tweeters archives to find
information about previous discussions on the lighting project and impacts
of lights on migratory birds. If anyone can key me into a date around which
those discussions occurred, that would help.

Mike Scuderi
Seattle District Corps of Engineers
P.O. Box 3755
Seattle, WA 98124-3755
michael.r.scuderi at usace.army.mil
(206)764-7205
FAX (206)764-4470


MESSAGE 1

Mike/Lori, I got a call from a man at the Corp of Engineers last year about
peregrine use of the Aurora Bridge, though this was in reference to seismic
retrofitting rather than lights. I do the record-keeping for peregrine
reports in Seattle, which is why he contacted me.
There are no peregrines nesting under the Aurora Bridge. In the past eight
years of observing and keeping records, we've only had sporadic reports of
peregrines using the bridge. All these sightings were of birds using the
light standards on top for hunting perches, and all were in fall and winter.
(I *have* seen Red-tailed Hawks under the bridge - suspect they may nest in
the nearby greenbelt).
There is a peregrine pair that nested unsuccesfully under the West Seattle
bridge this past year. The ledge is inaccessible except to avian predators,
and we *suspect* that a Great Horned Owl got the eyasses. I don't think that
a light shining directly on and illuminating the ledge would be a good idea,
though I don't know of any studies about this.
Our resident pair in downtown Seattle nest on a ledge that has lights on it,
but the lights don't shine directly on the nest box, and the light closest
to the box is turned off during the breeding season.
So far, there haven't been any peregrines nesting on the Ship Canal or
Ballard bridges, but I suspect it's just a matter of time, as the birds use
them the rest of the year.

Ruth Taylor

MESSAGE 2

Hi Mike,
There are no PEFA nest boxes on the Aurora Bridge. At present, there are
two nesting pairs in Seattle, the one at Washington Mutual and another on
the West Seattle Freeway Bridge. The latter failed last year.
We also put a box up on the I-5 Ship Canal Bridge last summer but it is
not occupied as yet. We expect use there soon however. Again, we have NOT
put any boxes up on the Aurora Bridge.
As for raptor use, in the 70's there was a pair of GHOWs that hunted
pigeons there regularly and may still. Merlins are often seen perching and
hunting from the top light posts during the day. As for use by other
species, including PEFAs, you want to have your associate contact Ruth
Taylor. She may have contacted you already. If not, give me a call and I
will give you her phone number. She has the most extensive data on this.
Best regards,
Bud


Bud Anderson
Falcon Research Group

MESSAGE 3

Mike Scuderi,

I'm responding to your message on tweeters requesting opinions on the
intended lighting of the Aurora Bridge.

I am a member of the Falcon Research Group, the volunteer organization
involved with monitoring Peregrine Falcons around Seattle. However, I do not
occupy an official position (as in Dept. of Fish and Wildlife for instance),
so my opinion does not carry any weight other than by virtue of what I've
learnt from extensive observation of the birds here.

First of all, there is no peregrine nest on the Aurora Bridge. I was one of
the people working with State and City agencies getting nest boxes placed in
a variety op locations, but not on this particular bridge. Over the years we
have seen birds around the Aurora Bridge, although I'm not sure the birds
have actually landed in the bridge superstructure. Some birds use the towers
carrying cables across the Ship Canal farther west, and there is a known
winter territory that includes both these towers and the I-5 Ship Canal
bridge to the east, so peregrines do fly around the Aurora Bridge regularly.

Second, the peregrines at the WAMU building downtown do just fine in their
highly urban setting with the many lighted structures in downtown all around
them. From our observations we believe they may even use the city lights to
do some nighttime hunting, although this is based on circumstantial evidence
and should not be construed as a positive effect of the lights. In order to
video tape the birds' behavior the lights on WAMU were kept on at night
during the nesting season and this did not appear to influence the birds'
behavior (they sleep perched sitting on light boxes with the lights on) or
productivity.

As you know we as a society have a tendency to focus on a few "popular"
species when we make decisions that affect a broad range of species. It is
good that the proposed lighting project's impact on nighttime activity of
birds is being reviewed, but I would like to see all birds that show
nighttime activity included. The most important thing is that the lights are
aimed at the bridge very carefully, so as to minimize the amount of light
that shines into the night sky past the structure. Migrating birds are
easily confused by strong lights during overcast or foggy nights. Since
Aurora Bridge is not the highest lit structure in this particular area (the
broadcast towers on Queen Anne to the south are much higher for instance), I
do not believe that PROPERLY AIMED lights at this bridge will add much to
the impact city lights have overall.

My understanding is that the lights aimed at the bridge are only temporary
(Martin Luther King Day to Earth Day 2000). Last I heard the current street
lights (aimed at the bridge deck) will also be replaced with more energy
efficient lights as part of the "festivities". I believe that this last
aspect, in the long run, has a valuable positive impact on our environment.
I only wish the "celebration" included installing energy efficient lights
everywhere, instead of lighting up structures of rather unappealing
architectural value.

I hope this is of help. Please don't hesitate to contact me if you have any
questions about this.

Sincerely,
Martin Muller, Seattle