I have a pair of deer whistles that I have yet to install on my truck (because I do not have my truck back from the repair shop after a collision with a deer). My son-in-law generously sent them to me, and I’d like to know if I will have a reasonable expectation that they will reduce the chances of a future collision.—Robert Bourke, via email
Sorry. You’re better off having no expectations. Everyone we asked—the experts at the British Columbia Conservation Foundation and at Eco-Kare International, among other groups that look at human-wildlife conflict mitigation—pointed us to research that disputes deer whistle effectiveness.
Deer whistles are designed to emit sound in a frequency range that deer can hear (but humans can’t). There hasn’t been a huge amount of research on the topic, but the published scientific studies have largely looked at deer hearing capabilities; for example, how sensitive are deer ears to the range of signals that whistles produce?; can deer separate that noise from other noises?; and whether the whistles—or tones at the same frequency as what deer whistles typically produce—actually change deer behaviour.
The results of all this research are inconclusive at best. (Well, one 2008 study in Austria—where deer whistles were invented—found that a “stimulus system” that consisted of a high-pitched sound in combination with a strobe light reduced collisions by 85 to 93 per cent. But, as a 2019 report from the U.S.-based Human-Wildlife Conflict Working Group points out, “this effect has yet to be replicated.”) Plus, even if deer can clearly distinguish the sound of a whistle from ambient sounds, and even if they react to it as a threat, there’s no reason to believe that effect would last. Deer are like pretty much every other wild creature: after a while, they start to ignore sounds that initially scare them.
Science has spoken. When it comes to deer whistles, “there’s no demonstrative effectiveness,” says Keith Munro, the wildlife biologist with the Ontario Federation of Anglers and Hunters. “So, as a result, they don’t appear to be a way to reduce deer-vehicle collisions.”
They get good reviews online. And you already own these deer whistles. Nothing wrong with installing them on your truck once it’s back from the shop, right? Except…if that were to make you more confident driving in deer country and, therefore, less attentive, your truck might end up back in the repair shop. And that could be a best-case scenario.
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This article was originally published in the June/July 2022 issue of Cottage Life.