Deer Whistles; do they work?

Insurance Institute for Highway Safety – Deer season means animal strike season on the roads

Do deer whistles work? Well, it depends who you ask. How do deers respond to sonic and ultrasonic sound waves or do they even react at all. The studies can’t seem to determine anything other than more studies are needed. One thing is clear, deer respond to electric shocks.

Animal-strike-related insurance claims are more than twice as frequent as the yearly average in November, when the search for a mate keeps the big bucks on the move, according to an analysis of claims from 2006 to 2018 conducted by the Highway Loss Data Institute.

The data does not include information about the type of animal. However, both the timing of the spike in crashes and the greater damage they cause suggest that most of these collisions involve deer, rather than smaller animals.

Deer Solution Blog

A famed researcher named Dietland Muller-Schwarze compares a deer’s hearing capability to that of a satellite dish. Both of a deer’s ears works independently, by comparing the sounds of each ear and detecting the direction of the source of the whistle.

“Sounds are alleged to repel animals by several mechanisms: pain; fear; communication ‘jamming’; disorientation; audio-genic seizure; internal thermal effects; alarm or distress mimics; and ultrasound. After time, most animals adjust and ignore a new sound, a process called habituation.”

Sonic Deterents in Animal Damage Control: A Review of Device Tests and Effectiveness

Bomford, M. and O’Brien, P. H. (1990). Sonic Deterrents In Animal Damage Control: A Review Of Device Tests And Effectiveness. Wild. Soc. Bull. 18: 411.

Ultrasonic Sounds – Both sonic and ultrasonic sounds have been found to be ineffective on deer. Emitting a high pitched noise that is inaudible to humans, ultrasonic deterrents are believed to be within the hearing range of a lot of animals.

“There is little data that mammals are repelled by ultrasonic devices. In fact, there is almost no evidence that any animal (vertebrate or invertebrate) avoids ultrasonic cues for more than short periods of time”

Deer horn

Researchers with the Georgia Fish and Game Department have pointed out several reasons for ultrasound devices not to work as advertised

  • Some deer whistles do not emit any ultrasonic sound under the advertised operating conditions (typically when the vehicle exceeds 30 mph).
  • Ultrasonic sound does not carry very well. It does not travel a long enough distance to provide adequate warning, and also is stopped by virtually any intervening object, so any curves in a road will block the sound.
  • Little is known about the auditory limits of deer, but current knowledge indicates that deer hear approximately the same frequencies as humans, and thus if humans can’t hear a sound, deer probably can’t either.
  • If deer could hear ultrasound, it is unknown if it would alarm them or induce a flight response.

The research paper

Of the fourteen repellents that were screened, 9 were found to be effective. These 9 repellents were investigated further under field conditions and only 1 repellent was found to be reliable and consistent in reducing deer feeding. 

A vertical electric deer fence was effective in repelling deer at field sites The fence offers producers a low-cost alternative to the 2.4 m woven wire fence.

Underground Snax opens on Quinpool Road in Halifax

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