Subject: Re: window kills
Date: Sep 9 11:36:51 1994
From: Scott Finet - scottf at ASTRO.OCIS.TEMPLE.EDU

This discussion inevitably raises the issue of preventative measures. A
previous discussion on BirdChat concluded that silhouettes were largely if
not totally ineffective as a means of preventing window kills.

A (Canadian?) documentary about the decline in songbirds recently circulated
amongst several Chatters included a sequence filmed in Toronto that
suggested that darkening tall buildings during the migration seasons would
help to prevent window kills. Has any research been done to prove or
disprove this? Are there proven measures that would help to prevent
window kills?

Scott Finet
scottf at


From: Eric Anderson Campbe Miller <eam2e at FARADAY.CLAS.VIRGINIA.EDU>

In the 1970's, the CN Tower in downtown Toronto, Ontario, was
killing thousands of migratory birds. Granted, the CN Tower, a
needle-shaped object whose builders boast that it is the tallest
free-standing structure in the world, is not in every sense
comparable to the average, broad, tall, glass-skinned commercial
tower. But when local environmentalists got the CN Tower to
reduce its lighting and to replace its continuously glowing
illumination with flashing signals, the number of birds killed
each night dropped radically.

Tall office buildings in the general vicinity of the CN Tower
continue to destroy fairly large numbers of birds. In order to
solve the problem, whole blocks of buildings would have to be
darkened-- if one tower attracts migrants, the others form a
labyrinth that characteristically confuses the birds, most of
which subsequently die not from an initial collision high up
the face of a tower, but rather down at lobby level among the
ornamental shrubbery. If a bird is stunned, gulls or rats find
it easy prey; and the unavailability of food gradually weakens
those birds that avoid intracranial haemorrhaging or predators.
By morning, throngs of office workers throw the unfortunate
survivors into continual panic.

Eric Miller


From: "Byron K. Butler" <BBUTLER at>
Subject: Re: Radio Antennae Kills

On Sat, 10 Sep 1994 13:25:08 GMT-6 Michael `Taylor' said:
>the fact that a radio anntennae in Wisconsin was in a migratory route
>and killed 5,000 birds in one night. Has there been research on the
>use of lights or noises to deter or warn them of the hazard?

Mike, you may find these sources useful, though they may not directly address
the above specific question. Byron Butler

Banks, Richard C. 1979. Human mortality of birds in the United
States. USDA Fish and Wildlife Service Special Scientific Report
- Wildlife No. 215, Washington, DC. 15 pp.

Avery, Michael L. 1978. Impacts of transmission lines on birds
in flight. USDA Fish and Wildlife Service FWS/OBS - 78/48
September, 1978. 151 pp. *** This publication contains a very
good bibliography on avian mortality ***


From: keith reid-green <kreid-green at ROSEDALE.ORG>

This is in response to Scott Finet's question about window kills. I'm not
sure of the efficacy of this solution as it applies to large buildings, but I
have one that works on my house.

In the Spring, we would take several hits on the living room picture window,
because a tree was reflected in it. A few hermit thrushes were killed. We
tried tacking up streamers, but that was not completely effective. Then I
hit upon the idea of building a frame that fits inside the outer window frame
and covering it with plastic insect screen (this is not screen made of
plastic insects :-} ). Not a bird has hit the window since I put it up three
years ago.

keith reid-green, Princeton, NJ
kreid-green at