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When People and Wildlife Collide

19 December 2013
Published in Science and Society
Written by  Julie Kiefer
When People and Wildlife Collide donjd2/Flickr

Each year, thousands of vehicles collide with deer and elk that are trying to get across Utah’s highways, often causing major property damage, and even death. To protect both people and wildlife, scientists are investigating the safest, most cost-effective ways to get big game across the road.

Carol Niles was driving her SUV at 75 miles per hour along Interstate 70 just west of the San Rafael Swell, when an elk suddenly jumped in front of her car. “I hit him square on and killed him instantly,” recalls Niles. “The bag came out in my face. I was on a mountain highway with a drop-off immediately to the left lane and it took me an enormously long time, I thought, to stop be able to stop my car.”

Luckily, she wasn’t seriously injured, but the collision caused $15,000 in damages. Even so, she can’t help feeling sorry for the elk. “I see him always. I see him in slow motion going up over my head, and he was so beautiful! It was a really bad, bad, feeling.”

Utah State University (USU) scientists estimate that there are 20,000 collisions with deer in Utah each year. That number doesn’t include elk, which are typically larger and cause more damage.

Collisions are particularly frequent in winter, as these animals try to navigate across highways that cut through migration routes that have been in place for generations. This is just one of the ways in which roads are hazardous to wildlife.

“They [roads] decrease the amount and quality of habitat that’s available to wildlife. We obviously have increased mortality from collisions with vehicles. Roads limit access to resources and impede movement,” explains Ashley Green from the Utah Division of Wildlife Resources (DWR). “Then of course roads can fragment populations and break up large populations into smaller, vulnerable populations.”

Utah has 44 highway crossings built specifically for wildlife, as well as thousands of other structures that they could use, such as bridges, tunnels, and drainages. Until recently, no one knew how much animals actually used any of them.

In a unique collaboration with the Utah Department of Transportation and scientists at USU, the Utah DWR launched the largest, most comprehensive study of its kind in the U.S. “As you’re building an underpass that costs hundreds of thousands to millions of dollars, and constructing fencing, you’ve really got to know that that stuff is working and it’s in the right place, and the type of the structures and the size of the structure that you’re putting on the landscape are really effective,” says Green.

To find what works best, USU wildlife ecologist Patricia Cramer placed motion-sensing cameras at 35 structures of all kinds on highways across the state. When an animal gets close, the camera snaps a series of pictures documenting whether it makes it through to the other side. Cramer and her team have sifted through nearly 1.5 million pictures over the past five years. It may sound tedious, but Cramer considers this the best part of her job.

“I like the stories that the pictures unfold,” says Cramer. “The bear, the mountain lion and her young coming through. The deer chasing the coyote through, which I thought was a great one. The mule deer encountering the skunk at the entrance and turning around and saying, ‘I think I’ll wait on that one.’ That’s kind of how I do it.”

Mule deer made 25,000 successful crossings over three years, more than any other animal. The two structures they used most were built specifically for wildlife. Both are on I-I5, south of Beaver.

“They went in in 2004 and I have documented over 18,000 times mule deer have passed through those two structures in a few years,” says Cramer. “Engineers did the math and those structures paid for themselves in reduced vehicle collisions in less than three years.” They’ve reduced collisions in the area by 90%.

But deer are picky. Only 4% of all deer crossings were through existing underpasses that were not made for wildlife. By looking at characteristics of structures that deer use most, Cramer learned they like ones that are wide, high, and short in length.

“If you know about prey animals, that makes perfect sense,” Cramer explains. “They want to be sure they can run through it without a mountain lion being perched somewhere in it, and then they like to have a left and right escape zone.” Her recommendations are already being used to design wildlife crossings across the country.

Cramer is also finding that not all species are comfortable using the same type of structure. In the first phase of the study, her cameras recorded only 45 successful elk crossings compared to tens of thousands made by deer.

That’s why she was surprised to see entire elk herds using a structure at the west end of I-70 this fall. She says they are just learning how to use the three-year-old wildlife crossing, which has a high arch-style opening they seem to prefer. Cramer thinks these latest findings will show how to safely move elk across highways.

“When you’re a scientist who sort of borders on an advocate, this is a great field because you can do something that is so applicable and see changes that help save wildlife lives,” she says.

Her work impacts not only animals, but also people. It’s been eight years since Niles hit the elk on I-70, and she still can’t shake the experience. “It’s really scary for me to drive through that part of the country,” says Niles. “I sometimes just have my husband [drive], especially if it’s at dusk or something like that when you know the animals are going to be out.”

As part of the study, Cramer documented a need for a new deer and elk friendly crossing along the same stretch of highway where Niles had the accident. The Utah Department of Transportation is taking the recommendation under consideration.

 

Photo credit: Patricia Cramer

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