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ask joanne

I'm hearing about drivers crashing into animals more and more recently. It has me wondering whether I should take precautions. Do deer whistles actually work to prevent these kinds of accidents? – Marie in St. Albert, Alta.

Thankful though we are for our beautiful land and wild country, the highway, unfortunately, is where human and wildlife populations often collide. Data from Transport Canada reveals that an average of more than 100 large animal and vehicle collisions occur across the country each day. Quite an astounding number.

But could these accidents have been prevented by the whistles you mention? They're purported to function by producing ultrasonic noise when a vehicle exceeds certain speeds.

"Unfortunately, there is no hard evidence that deer whistles work – that deer can actually hear the whistles or, if they do, that they're turned away from the road," says Russ Rader, spokesman for the U.S. Insurance Institute for Highway Safety.

Rob Found, a PhD candidate and wildlife researcher associated with the University of Alberta, agrees that whistles are marketed on flawed evidence. "The bottom line is they don't work.

"They've done a number of tests on these whistles, and a lot of them are actually outside the range of the hearing of deer or other ungulates that would be on the roads. Another problem is they tend to be a low frequency, and the volume really blends into the noise of the vehicles and the highway noise in general, so they really don't jump out as an alarm."

So what can you do to avoid a collision?

Understanding when you're most likely to hit a deer is important.

"Night isn't actually such a bad time to be driving, but dawn and dusk are horrible. That's when deer and other ungulates are most active and focused on eating, so they're not paying much attention to the roadway. For a motorist, visibility is also terrible at that time if you're driving into the sun," says Found, who is currently studying elk behaviour in Banff.

Avoiding deer also means considering the particular times of year when they're most active. "In places with a seasonal climate, such as Edmonton, we see a peak in collisions in June near the calving season for deer because the mothers have to eat a lot to nurse their young," he said.

"But in all jurisdictions where these collisions are recorded, they find a major peak in late fall and early winter. That's the mating season for deer, movement rates increase dramatically and the males tend to get so focused on mating that they're really reckless near roads."

Maintaining a speed appropriate for driving conditions is always important, and this includes peak wildlife periods.

"From an individual driver standpoint, the best thing you can do is be alert in areas where deer are prevalent, and during peak periods," says Rader.

"The most important thing you can do is slow down, because crashes are often unavoidable and slowing down helps prevent a more serious crash from happening after the impact with the deer. A lot of the serious crashes involving deer happen in the subsequent impacts when vehicles go out of control and hit other things, or go off the road and roll over," says Rader.

"Remember, if you're driving and see one deer, chance is there are more. If one crosses your path, you need to prepare recognizing that other deer are likely to follow."

There are precautions we can all take to reduce wildlife collisions, but are the authorities helping us out?

There are other ways, says Found, to help ensure the safe co-existence of wildlife and automobiles. He's conducted studies that show that more selective placing of wildlife-crossing warning signs would help.

"I had the idea that the warning signs, because they're cheap and easy to install, were being overused. An analogy would be the overuse of penicillin: it's used so often to fight infection that the effect is lost. My experiment looked at using historical locations for deer-vehicle collisions, and modelling these hotspots – where they were being hit the most, and with new roads where they were likely to be hit the most – and only placing the signs there, rather than just putting them up anywhere. I did find this significantly reduced deer-vehicle collisions at those hotspots."

The best way to prevent deer-vehicle collisions, Found says, is to have a place where wildlife can safely cross the road whenever they want.

"Formalized wildlife crossings are quite rare; the top place in the world for them that I'm aware of is Banff. It's an ongoing experiment as they've been adding not just wildlife underpasses but actual overpasses all through Banff National Park.

"Because there's so much wildlife here, they've fenced off the Trans Canada Highway all the way to Lake Louise, and that's significantly reduced these collisions. But the fencing is incredibly expensive and the crossings can be hard to install, so most jurisdictions just can't afford it."

Rather than rely on whistles, I'd use sound judgment for the timing of your trips, speed control and knowledge of peak local wildlife periods.