Deer and Disease

When it comes to polarizing creatures, perhaps none is as divisive as the white-tailed deer

It's not only wild animals that suffer from living too close to people. We have our own concerns about living in such proximity.

Even if you appreciate that bats eat pest insects and help pollinate plants, you probably don’t want them living in your attic, says Linda Huebner, the former assistant director of advocacy at the Massachusetts Society for the Prevention of Cruelty to Animals who oversaw its Living with Wildlife program for six years. “Although the risk is very small, bats are still the source of nearly all U.S. rabies cases in humans,” she says.

Raccoons not only tear apart garbage bags, they also shed a roundworm in their feces that’s potentially fatal to humans, she says. And although harmless in most locations, beavers can flood out septic systems and roads with their impressive dams.

Potential problems like these don’t just create human-animal conflict—they also spark human-human conflict, says Huebner, who received a master’s degree in animals and public policy from Cummings School in 1996. “You know who always seem to own homes right next to each other? Someone who wants to see wildlife every day—and someone who doesn’t,” she says.

Sam Telford

Sam Telford. Photo: Alonso Nichols/Tufts University

When it comes to polarizing creatures, perhaps none is as divisive as the white-tailed deer.

“Deer are evil. You can quote me on that,” says Sam Telford, an expert on tick-borne diseases and a professor at Cummings School. An animal lover, Telford says he’s a public health official at heart—and that Bambi’s offenses speak for themselves.

Telford has spent 30 years studying how the deer population is related to the number of ticks present in an area—he’s found as many as 300 ticks on a single deer. “That’s only one week’s accumulation,” he says, “and if half of those are female, that’s 150 ticks, each enjoying a meal that will allow it to lay another 2,000 eggs.”

Deer ticks can carry five different infectious diseases that affect people, Telford says. The alarming growth in Lyme disease cases alone—they nearly doubled between 2004 and 2009, when almost 38,500 people were diagnosed in the U.S.—is reason enough to be grim about ample deer populations. “Car accidents [involving deer] are a public health issue, too,” notes Telford.

Most communities in eastern Massachusetts have about 20 to 25 deer per square mile, according to Telford. Rutberg notes that in the Mid-Atlantic states, including New York, Pennsylvania and Maryland, there can be 30, 40 or more deer per square mile.

To curb the incidence of Lyme disease alone, Telford and Rutberg say the deer population needs to be reduced to five or fewer animals per square mile. This could be best achieved through an increase in hunting, Telford says, because it’s a free solution. However, in the densely populated Northeast, fewer and fewer suburbs have land open to hunting with firearms. “Out of two square miles, there might be 50 or 100 acres where you can discharge a gun,” putting more than 90 percent of the land off-limits, Rutberg says.

As a result, public discussion in many communities has turned to an expansion of bow hunting. Throughout the eastern U.S., town meetings about deer control draw equally large numbers of hunting supporters and opponents.

Such was the case in Hastings-on-Hudson, N.Y., a small village 16 miles north of Manhattan. As a result, the mayor opted for a radically different approach to reduce the 120-deer herd that has overrun the town’s two square miles: the country’s first birth-control study of free-roaming deer.

Rutberg will lead a team seeking to inject 40 to 50 does with a contraceptive vaccine over the next two years. The community hopes the vaccines—which work for at least two years with one dose and have no harmful side effects—will reduce the deer population by 40 percent.

“It won’t be easy, but we wouldn’t be attempting it if wasn’t doable,” says Rutberg, who has studied the effectiveness of birth control in deer and wild horse populations for more than 20 years. “We’ve shown that we can reduce deer populations in relatively confined spaces” by 30 to 60 percent, he says.

More than 50 residents volunteered to assist with the research project. Children and adults will track the movement of deer in their neighborhoods and report to an online database. Others will monitor whether deer consumption of seedlings declines as a result of the program. The local high school environmental studies class is helping set up fenced areas to assess how deer grazing affects local vegetation.

Rutberg says that he’s impressed by the extent to which community members have been involved in the birth-control project. “There’s a lot of concern these days about what is known as nature-deficit disorder,” he says. The term was coined by the journalist Richard Louv in his 1995 book Last Child in the Woods, in which he argues that kids’ behavioral problems are on the rise because they’re spending less time outdoors. The Hastings-on-Hudson program, Rutberg says, “has provided an extraordinary opportunity for people to get more engaged with wildlife and their own habitat.”

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