Chapter 1: The Role of Wolves in Wisconsin

The wolves inhabiting Wisconsin may unwittingly be providing a significant service, potentially preventing numerous accidents involving deer. Each year, approximately 19,757 residents of Wisconsin encounter deer on the roads, resulting in around 477 injuries and eight fatalities. Jennifer Raynor, a natural-resource economist from Wesleyan University, suggests that without the presence of wolves, these numbers could be even higher. “Some lives are spared, injuries are lessened, and a considerable amount of damage and time is saved due to the presence of wolves,” she explained.

Wolves typically roam near human-made pathways, including trails and roads. By hunting deer in these regions or by instilling fear that keeps deer away, they may help reduce deer presence near vehicles. An analysis conducted over 22 years by Raynor and her team revealed that wolves in Wisconsin have contributed to a 25% decrease in deer-related vehicle accidents, saving the state approximately $10.9 million annually in damages—an amount significantly greater than what is compensated for lost livestock or pets. “The best part is that wolves carry out this crucial task all year round at no cost to us,” remarked Liana Zanette, an ecologist at Western University, who was not part of the study. “It seems beneficial for the counties where wolves are present.”

However, the presence of wolves often stirs up debate.

By the mid-20th century, European settlers had nearly wiped out the gray wolf population across the continental United States. Following legal protections, wolf populations began to rebound. They have naturally returned to certain areas, such as Wisconsin, and have been intentionally reintroduced in places like Yellowstone National Park. Yet, the impact of wolves on surrounding ecosystems remains a contentious issue. The species has frequently been removed from and reinstated under the Endangered Species Act. In November, Colorado voted to allow wolves back, but the decision was a close one. As my colleague Michelle Nijhuis once described, they are “the most political animal.”

Raynor’s research, if confirmed, could introduce three crucial aspects to the ongoing discourse surrounding wolves. First, most studies on wolves have taken place in national parks like Yellowstone and Isle Royale, which are largely insulated from human impact. Such studies provide limited insights into how wolves might behave in more populated regions filled with towns and farms. For wolves to thrive in the U.S. or even be reintroduced in more states, they must learn to coexist with humans in environments that resemble Wisconsin rather than Yellowstone.

Second, Raynor pointed out that those who appreciate the existence of wolves are often not the same individuals living in areas where wolves roam. Urban wildlife enthusiasts may find comfort in the knowledge that wolves exist, but rural residents face the harsh reality of livestock and pet losses. While the advantages of wolves may be abstract for urban dwellers, the costs are concrete and distressing for rural inhabitants. Nevertheless, deer-vehicle collisions occur in both urban and rural settings, meaning that rural communities also indirectly benefit from wolves, often without realizing it.

Third, public discussions tend to emphasize the potential negative economic effects of wolves on local communities, according to Rebecca Niemiec, a social scientist at Colorado State University studying conservation attitudes. However, she asserts that Raynor’s findings present “compelling evidence” that wolves can also serve as a positive economic asset by preventing accidents.

Critics might argue that there are simpler solutions to prevent deer from colliding with cars than reintroducing wolves. Raynor acknowledges that alternatives exist, but many come with drawbacks. Inexpensive solutions, like standard warning signs for drivers, have proven ineffective. More effective options, such as constructing overpasses for deer, are prohibitively costly and can only be implemented in areas with severe collision rates. “What about everywhere else?” Raynor asked. “Wolves provide a cost-effective solution compared to multimillion-dollar investments that only address isolated intersections.” Notably, collisions involving wolves are rare; only 21 were reported between April 2019 and April 2020, while deer-related accidents average around 20,000 annually. It seems almost absurd to propose, but the challenge of deer-vehicle collisions might be addressed effectively by the presence of wolves.

To substantiate this claim, Raynor and her co-authors, Corbett Grainger and Dominic Parker, compiled various pieces of evidence. They observed that since the 1990s, when wolf populations in Wisconsin began to increase, deer numbers stabilized in 29 counties with wolves, while they continued to rise in 34 counties without them. When wolves first entered a county, the rate of road accidents involving deer typically declined. Although deer-vehicle collisions are notably less frequent in areas with wolves, other types of collisions do not show a similar reduction. These trends imply that wolves have indeed contributed to safer roads in Wisconsin, regardless of other variables. “While establishing direct causation is beyond the study's scope, the evidence strongly supports the notion that wolves play a pivotal role,” Zanette stated.

However, Guillaume Chapron from the Swedish University of Agricultural Sciences, who studies large predators, believes that the research team has not sufficiently detailed their statistical methods or uncertainties, making it difficult to replicate their findings. “They may have uncovered a new dimension to the role of wolves, but their paper lacks critical evaluations,” he commented. “I’m sure it will be well-received by wolf advocates, but less so by statisticians.”

Adrian Treves from the University of Wisconsin at Madison, who also examines large carnivores, reviewed the study and considers it a “valuable contribution, but it needs further validation.” He suggested focusing on counties with varying wolf populations while controlling for factors like traffic patterns and deer numbers. “This is just the beginning of understanding a potentially significant biological and economic relationship,” Treves noted.

If wolves are indeed enhancing road safety, an important question arises: How? Raynor’s statistical analysis suggests that wolves are lowering collision rates disproportionately compared to the number of deer they consume. She posits that their presence primarily induces fear rather than resulting in direct predation. Their mere existence fosters an environment of apprehension, which deters deer from approaching roads and other heavily trafficked areas. “This makes perfect sense,” Zanette remarked. “Predators typically instill fear in prey far beyond their actual predation capacity. This principle is increasingly recognized in ecology.”

Conversely, Matthew Kauffman from the University of Wyoming remains skeptical, drawing from experiences at Yellowstone. Since 2001, some scientists have claimed that reintroduced wolves benefit the park's aspen and willow trees by scaring away overpopulated elk. Kauffman later complicated this narrative, showing through GPS collar data that elk seldom flee from wolves and that their behavior does not significantly affect aspen survival. He concluded that wolves might alter their prey's behavior in more nuanced ways. In Wisconsin, they may be selectively hunting the least cautious deer, which are more likely to dart in front of cars. To confirm this, Kauffman stressed the need for direct observation of deer and wolf behaviors through tracking collars, something Raynor's team has not yet pursued.

The economic analysis presented by Raynor’s team also has limitations. They estimate that wolves prevent $10.9 million in damages annually linked to deer collisions, while costing $174,000 in compensation for injured pets and livestock—a ratio of 63 to 1. However, Raynor acknowledges that these figures are not directly comparable; collision costs are calculated comprehensively, while compensation figures overlook the emotional toll of losing animals, stress-related impacts on livestock productivity, and expenses incurred by farmers to protect their animals. Although wolves appear to provide benefits significantly greater than their costs, “I can’t determine what the ratio would be with a more thorough accounting,” she admitted.

Even if benefits and costs were equal, the advantages would still be substantial and could save lives. Raynor also notes that wolves might offer additional economic benefits. By either predating on or instilling fear in deer, they may keep these animals away from agricultural areas. As part of an ecological network that includes coyotes, foxes, small rodents, and ticks, wolves could also help reduce the incidence of Lyme disease. While these ideas remain speculative, they warrant investigation, especially in discussions about potential wolf reintroductions in various regions of the country.

“There’s a significant need for this type of research,” asserted Peter David of the Great Lakes Indian Fish and Wildlife Commission, representing 11 Ojibwe tribes in Wisconsin and neighboring states. “It sheds light on a new realm of previously unrecognized benefits that wolves bring to ecosystems, even those heavily influenced by human activity.” David also reflected on Ojibwe teachings about humility: “We should proceed cautiously, recognizing and valuing all components of our ecological landscape, even those we don’t fully understand yet.”

Chapter 2: Addressing Deer-Vehicle Collisions

This video discusses the impact of deer-vehicle collisions in rural areas and explores potential solutions involving wildlife management.

This video outlines strategies to avoid deer collisions, emphasizing awareness and wildlife conservation efforts.