A pair of eyes caught in the headlights. A stab at the brakes. A sickening thud. A deer careens off your car and lies twitching on the side of the road.

Avoidable? Yes and no. Yes, if you slow down and drive cautiously where deer crossing signs are posted or you suspect the animals may be feeding. No, if you rely on animal warning devices called "deer whistles," according to researchers and state police.

Deer whistles, mounted on the fronts of cars, trucks, and motorcycles, allegedly produce ultrasonic frequencies and/or audible sounds from the wind rushing through them. These sounds are supposed to repel or warn animals, particularly deer, elk, moose and dogs, of oncoming vehicles.




The manufacturers claim that two European studies proved that the whistles work. Not so. They were initially tried in Europe about 25 years ago but research did not prove them to be successful. Now they are being sold in the United States with European claims. The study from Finland, which the advertisers refer to, states that from all of the experiments conducted "it was unsure that the animals were not disturbed by the approach itself, so that the whistle sound was the only disturbing factor." The second study from Switzerland concludes that the whistling sound, which is well within the human hearing range, is so weak that it is overlaid by the noise of the moving vehicle. A scientific advisory panel from the World Society for the Protection of Animals states, after extensive review, that there is no known data "that shows that such devices can actually stop an animal crossing the road, which is the main purpose of the device."

Even if the devices were effective, they would soon become clogged with insects and dirt (since they are mounted on the front of the vehicle) and would stop working.

The state police in Ohio, after months of testing, found no significant decrease in patrol car/deer accidents after the warning devices were installed. In fact, more accidents were reported by the officers after the whistles were installed than before for the same period of time and stretches of highway. Tests conducted in Utah, Georgia and Wisconsin also concluded that deer whistles don't work.

The odds are you won't hit a deer. Your best protection is to drive defensively, particularly as the sun sets. This is when most vehicle/deer accidents occur. Slow down when you see one deer. More often another is right behind it.

Until there is some solid evidence, other than personal testimonials, that deer whistles are effective, keep your money in your pocket.



--------------------------------------------------------------------------------

Leonard R. Askham former WSU Associate Professor and Associate Research Scientist, Vertebrate Pest Management, Department of Horticulture and Landscape Architecture.



Issued by Washington State University Cooperative Extension and the U.S. Department of Agriculture in furtherance of the Acts of May 8 and June 30, 1914. Cooperative Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, color, gender, national origin, religion, age, disability, and sexual orientation. Evidence of noncompliance may be reported through your local Cooperative Extension office. Trade names have been used to simplify information; no endorsement is intended. Published February 1992. Subject code 440. A