The Problem with Wildlife Crossings: Why Some Animals Are Scared to Cross the Road

Written by HLRBO - Alexandra Carter| 2/6/2023

Are the wildlife crossing signs set up with the intention of helping protect animals actually causing them harm? New research suggests many animals are actually fearful of using wildlife crossings.

For the recent UCLA study, a group of researchers studied an underpass wildlife crossing in Alberta, Canada, to see how animals used it. Video from the crossing showed some deer and elk would suddenly stop foraging for food and become fearful when cars passed at the crossing — some fled entirely. The researchers concluded that animals that looked the most scared or vigilant were the least likely to use the crossing, while other animals, including rodents, would cross without thinking twice. One of the researchers clarified that these rodents, like raccoons, may be so used to human activities they have grown comfortable with it, while others who are not around humans often are more cautious.

The study reinforces how animals respond dynamically to human behavior, so much so that it influences if and how they use wildlife crossings.

What the researchers ultimately found was there is no universal set of behaviors for animals, meaning there is no one-size-fits-all solution when it comes to designing wildlife crossings.

The research team said that it comes down to whether each animal views the crossing’s structure as protective or obstructive. Animals that consider shrubs and bushes as safe havens and hideouts will use covered wildlife crossings. But on the other hand, other animals may view the covering as dangerous.

“On these wildlife crossings, different species behave differently, and we need to think about designing crossings, as other people have already realized, we need to think about designing crossings to sort of be bespoke for the species you’re dealing with,” co-author Daniel Blumstein, a UCLA professor of ecology and evolutionary biology said.

The researchers hope this study will help inform the construction of wildlife crossings around the country.

“If we can figure out ways to leverage wildlife behaviors, we may be able to make wildlife crossings more effective,” co-author Eric Abelson said. “For example, walls to dampen sound or to reduce the visual effects of passing headlights may encourage the use of crossing structures. We hope that this study is just one of many that will examine different wildlife species and levels of traffic to better develop tools that increase the use of crossing structures by wildlife and, ultimately, protect the lives of humans and wildlife.”

Each year, the Federal Highway Administration estimates between 1 to 2 million accidents involve drivers and wildlife on U.S. roadways. Annually, 200 people die in these crashes, and 30,000 people are injured, costing our economy $8 billion.

Vehicle collisions can prevent wildlife from reaching food, water, seasonal habitat, or mating opportunities, while fish can get blocked by bridges and culverts that are clogged, too small, or poorly designed. This is why animal crossings are so important. But if they are not working effectively or, worse, having a detrimental effect on wildlife populations, the study authors urge it’s time to rethink how they’re designed.

Optimizing wildlife crossing design is also at the top of President Joe Biden’s list. In 2021 he signed The Infrastructure Investment and Jobs Act, which includes a comprehensive wildlife crossing program in this bill that includes job training, research, and $350 million toward wildlife crossings and fish passages like bridges, tunnels, and culverts.