Preventing Bird-Window Collisions

To: <>
Subject: Preventing Bird-Window Collisions
From: "Stephen Ambrose" <>
Date: Wed, 24 Jun 2009 10:57:22 +1000
Dear All, 


I've been in regular communication with Professor Dan Klem Jr of Muhlenberg
University, Pennsylvania over the last 18 months about bird collisions with
buildings and other structures, as part of a long-term ecological
consultancy project I'm involved in. Professor Klem is recognized as an
international expert on such issues and has published many scientific papers
on bird collisions and mortality. He is presently lobbying architects to use
glass window panes that are coated on one side with a special UV-film, which
birds can see but humans can't. The use of this film in experimental trials
in the United States has reduced bird collisions with window panes
significantly. There are also other techniques that are effective in
reducing bird strikes at windows (e.g. the use of ceramic frit glass and
UV-reflective decals). The abstract of the latest scientific paper that I
received from Dan by email this morning [published in the Wilson Journal of
Ornithology, Vol. 121(2), June 2009] is shown below:


Preventing Bird-Window Collisions no access

Daniel Klem Jr
pg(s) 314-321

 <javascript:showAbstract('10.1676/08-118.1','08-118.1');> click this button
to openAbstract


Birds behave as if clear and reflective glass and plastic windows are
invisible, and annual avian mortality from collisions is estimated in the
billions worldwide. Outdoor flight cage and field experiments were used to
evaluate different methods to prevent collisions between birds and windows.
Stripe and grid patterns of clear UV-reflecting and UV-absorbing window
coverings presented an effective warning that birds avoid while offering
little or no obstructed view for humans. Birds used UV-reflected signals to
avoid space occupied by clear and reflective sheet glass and plastic. Window
coverings with effective UV-reflecting and UV-absorbing patterns as warning
signals can prevent unintentional killing of birds from collisions with
windows. One-way films that made the outer surface of windows opaque or
translucent were successful in deterring bird strikes. Ceramic frit glass
consisting of a visual pattern of densely spaced 0.32-cm diameter dots, 0.32
cm apart was an effective collision deterrent. Uniformly covering windows
with decals or other objects that are separated by 5 to 10 cm was completely
or near-completely effective in preventing strikes. Twice the number of
window strikes occurred at non-reflective sheet glass compared to
conventional clear panes. Continuous monitoring of windows revealed one in
four bird strikes left no evidence of a collision after 24 hrs and, without
continuous monitoring, 25% of bird strikes were undetected.


The chemical company that has provided Dan with the UV film for his
experiments, CP Films Inc., has a marketing department that needs to be
convinced that there is a viable market for such a product. Therefore, Dan
has asked me to invite as many people as possible to write to CP Films Inc.
to convince them of the importance of using UV film on windows to prevent
bird strikes and that there would be a ready market for the product. So, if
you could lobby the company about this and perhaps pass on this email to
architects, construction companies, housing authorities, councils, other
government agencies, and other relevant people for them to do the same, it
would be greatly appreciated.


Dan indicated that all correspondence should be sent to Dr. Tony Port, CP
Films, Inc., P.O. Box 5068, Martinsville, VA 24115; email =
 Apparently, Dr Port is the chemist that has been
working in collaboration on Dan's experiments.





Dr Stephen Ambrose






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