Research Indicates Method to Prevent Birds From Striking Windows

The latest article published by bird-strike expert Dr. Daniel Klem, Jr. reports on a new type of add-on window covering that was found to prevent birds from striking windows.

"The novel film presents a pattern composed of UV-reflecting and UV-absorbing areas," said Dr. Klem, the Sarkis Acopian Professor of Ornithology and Conservation Biology at Muhlenberg University, Allentown Pennsylvania. "This film was developed in collaboration with Dr. Tony Port, a research and development chemist for CPFilms, Inc. in Martinsville, Virginia."

"My experiments reveal that this film is an effective deterrent, resulting in birds behaving as if they see and avoid windows covered with this film," Dr. Klem said. "The film is an exterior film, and the hopes of the company are that it can be used to retrofit existing windows in existing buildings worldwide."

Article abstract: "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. ..." from June issue of the Wilson Journal of Ornithology.

"My previous work reveals that lethal bird-window collisions are possible wherever birds and windows mutually occur, so all windows in all buildings are potential candidates for this protective film," Dr. Klem said. "Naturally, the highest image priority windows where regular and consistent fatal strikes occur should be recommended as the first application of this film, when and if it becomes available."

"CPFilms, Inc. is currently evaluating whether a market for this film exists. The marketing department of this company must be convinced that there will be clients that will purchase and use this film."

"I have tried to enlist the help of select colleagues who are concerned about this important conservation issue for birds and people to write CPFilms and advocate for their commitment to produce and offer the film for commercial sale," Dr. Klem said. "If they do this, the film can immediately address existing problem sites."

The address for the company, and where to send correspondence to their marketing department in support of commercial development of the window covering, is:

CPFilms

Box 5068

Martinsville, Virginia 24115

"The long term solution is to convince glass manufacturers to incorporate similar protective patterns as coatings on new sheet glass for use in new construction."  

"At least to date, no glass manufacturers have contacted me with a serious interest in developing such a bird-safe glass," Dr. Klem said. "There is a German glass manufacturer that has produced what they claim is a bird-safe glass called ORNILUX, but they have not released specifications of their glass such that I could compare it to those signals I have prepared, nor have they formally published in peer-reviewed scientific journals the effectiveness of their glass in deterring bird-window collisions. In advertising literature, they have described laboratory tests that they claim have produced effective deterrence.  

"I continue to work on this topic, gathering evidence of bird kills at windows worldwide, and by whatever means possible trying to encourage CPFilms and glass manufacturers to invest in products for commercial sale to save more bird lives from windows.

"As important a group to educate on this conservation issue are architects and other building professionals, so that they will create market demand for bird-safe windows and further convince glass manufacturers that such a product is worth their effort, from their commercial sale perspective and for the environmental ethic perspective; that is, the promise such products have to annually save billions of bird lives the world over."

The experiments reported by Dr. Klem in the current article, also indicate that "strike frequency at intensely monitored sites is likely to be incomplete and conservative because some impacts may not leave any evidence of a collision. Moreover, predators and scavengers may have removed some casualties that were not detected."

"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," according to the abstract of the article titled Preventing Bird-Window Collisions which describes in detail the rigorous scientific methods used to determine the professor's latest findings.

Dr. Klem has published numerous scientific and popular articles on this subject since 1976, and continues to investigate this world-wide problem.