Humans and Nature: Hunting Serves the Environment By Controlling Overpopulation, Study Shows

A wild boar in the Alytus regon of Lithuania. A new study highlights the role of hunting in controlling overpopulation of wild boars in Spain. Petras Malukas/AFP/Getty Images

As most U.S. citizens living in 2017 know, hunting is controversial. As a recreational sport, hunting is considered reprehensible by some people and completely natural by others. The issues at play are thorny and heated, and recent news—such as the revelation that poachers scan scientific studies for the locations of rare species or the news of Donald Trump, Jr. shooting prairie dogs in Montana—do not bring us closer to understanding what useful role, if any, hunting may play in our interaction with our surrounding environment.

A new study from Europe may provide some useful middle ground. Researchers found that when it comes to problematic abundance, hunters may serve their ecosystem well. By regulating populations, hunting may help regulate the environment.

Wildlife researcher Pelayo Acevedo and colleagues at the Catalonia Institute for Energy Reserach, part of the University of Barcelona, wanted to know whether hunting could effectively control the wild boar population in northewestern Spain. In the province of Asturias, hunting is traditional among the rural locals, and the wild boar known as Sus scrofa are plentiful.

To measure the impact of hunting on the wild boar population, the researchers gathered data on the number of wild boars killed at several game reserves and hunting estates in Asturias. They hypothesized that the total bag—that is, the number harvested from the wild—after a ban would be greater than before the ban. The difference between the pre-ban bag and the post-ban bag, the researchers write in their study, just published in European Journal of Wildlife Research, "could provide an indication of hunters' relative contribution to wild boar population regulation."

The investigators, led by Francisco Quirós-Fernández, found that the number of wild boars hunted increased during the study period, from 3,723 in the 2000 to 2001 hunting year to 7,593 in the 2013 to 2014 season. Before any bans were instituted, the mean annual increase in the hunting bag was 8.46 percent. But after a ban lasting between one and three years, the bag grew by more than 40 percent at six of the hunting sites. Following that spike, the annual rate evened out and sometimes decreased, indicating "that hunters are indeed able to reduce wild boar abundance, at least in this study area," the researchers write.

A hunter attends a big game hunting in western France. A new study found that hunting may help control wild boar populations in northwestern Spain. Jean-Sebastien Evrard/AFP/Getty Images

The study also theorized about how the Asturias wild boar population would have grown in the absence of hunting: exponentially. They acknowledge that this projection is "obviously fictitious," but does suggest the important role that hunters play in regulating the wild boar population.

In Europe, the Sus scrofa population has been increasing by 20 percent each year. That could pose problems. The overpopulation of wild ungulates, a group that these boars are part of, is implicated in traffic accidents, agricultural damage, conservation challenges and health risks (although all the studies highlighting these problems were published by the same journal).

How translatable are these findings to the U.S.? "It's complicated," says Paul Curtis, a wildlife specialist at the College of Agriculture and Life Sciences at Cornell University, "and the article oversimplifies it."

Curtis says that hunting can help but is often not enough to control the damage wrought by animal overpopulation. White-tailed deer are a prime example. In the northeastern U.S., this burgeoning population is diminishing biodiversity. These deer eat native trees and wildflowers that other animals rely on, but hunting has not been able to reduce this impact, says Curtis. The current white-tailed deer population in the U.S. is estimated at 30 to 35 million animals.

Still, he says, "hunting can help reduce the damage." In rural areas, deer hunting, says Curtis, "may come close to stabilizing deer numbers but won't control them." Other experts agree. "Without a doubt, legalized hunting is one of the most cost-effective tools for maintaining wildlife populations in check that lend themselves to harvest," says Billy Higginbotham, a wildlife specialist at Texas A&M University. Suburban areas, where the deer population has proven exceedlingly difficult to control, offer an insight to what happens in the absence of hunting.

Curtis also emphasizes that hunters don't always help. He cites the example of wild boar in Tennessee. When the state listed the population occupying parts of Great Smoky Mountain National Park as a game animal, the intention was to prevent hunting: shooting game animals in the park is illegal. But the designation was too tempting to recreational hunters, who transported animals out of the park so they could be legally hunted. "It's a double-edged sword," says Curtis.

On the flipside, Curtis wonders about the diminishing interest in hunting. "It's questionable whether there will be enough hunters in the future to really manage wildlife populations," he says. Higginbotham also notes the health benefits for humans. In Texas, the annual deer harvest averages 450,000 animals, providing up to 14 million pounds of boneless venison, which is much leaner than beef. With wild boar populations on the rise in the U.S., some hunters may have yet another food source and a way to take care of the environment.