Quirks & Quarks

Wolves can reduce collisions between cars and deer, saving lives and money

The reintroduction of wolves to a landscape may be the cheapest and most effective method for reducing car-deer collisions

In Wisconsin when wolves returned deer started avoiding roadways, cutting accidents by a quarter

Wolves like this one in Wisconsin are reducing the number of collisions between cars and deer (Wisconsin DNR)

A new study suggests the presence of wild wolves on the landscape in Wisconsin is indirectly saving human lives and billions of dollars in damages by reducing the number of collisions between cars and deer.

More than a million car-deer collisions occur in the U.S. every year causing many injuries and deaths, and with an associated cost of about $10 billion US, according to the researchers. And while national statistics aren't available in Canada, there are likely tens of thousands of similar collisions on Canadian roadways. 

The new study by Jennifer Raynor, a natural resource economist at Wesleyan University in Connecticut, and her colleagues, looked at how accidents declined in Wisconsin, one of the few states with a wild wolf population, as wolves returned to the landscape.

Wisconsin wolves

Wolves were eradicated from most of the United States by the 1960s thanks to an aggressive bounty program. A small population that survived in northern Minnesota gave rise to the current population of 1,200 wolves found in Wisconsin today. 

Wolves hunt the state's 1.6 million deer and preferentially use open space like roads and trails to move efficiently. When wolves are present in these areas the deer learn to retreat to the safety of forests. As a result, deer are much less likely to be hit by cars.

Deer are driven away from the danger of roads by their fear of wolves (Shutterstock / Gert Hilbink)

The not-so big, bad, wolf

Over 22 years, Raynor found an average of just under 20,000 collisions per year, which includes nearly 500 injuries to humans and eight deaths. 

However, the number of collisions has decreased by 24 per cent in recent years in areas in counties in which wolves moved in. This amounts to a saving of about $11 million US per year. Raynor points out that this figure is much larger than compensation that is paid out to farmers and ranchers every year for the loss of livestock to wolves. 

Raynor said her study suggests the financial benefit of wolves may be worth considerng when planning future reintroductions to areas where they are likely to interact with humans. Currently, there are a variety of methods for reducing car-deer collisions, including signage and fencing, but the introduction of wolves may be the cheapest and most effective.


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