Researchers carrying dart guns and deer birth control fanned out across Head of the Harbor last week, part of a study that trustees hope will gradually shrink a population estimated at 200 to 250 that is now consuming much of the landscaping and natural undergrowth in this village’s 3 square miles.
Now in year two of six, the study is intended to test delivery methods and technologies for a long-lasting form of the immunocontraceptive PZP (porcine zona pellucida), which costs about $500 per deer to administer, plus $100 for dart-delivered annual boosters. State and federal authorities only permit its use in research, though restrictions could be eased in the future.
But some residents — including several officials — say the village is at a breaking point now and should employ lethal means like recreational hunting or a cull by professional hunters.
“Is it legal for me to stab a deer? Because that’s how angry I am,” said Leighton H. Coleman III, the village’s normally mild-mannered historian, at a Feb. 26 trustees meeting. The plants on the bluff outside his home had been eaten down to dirt, he said. “I’m just shocked every time I go outside.”
Another resident, Michael Fishkin, said “it’s like Agent Orange has been sprayed” on the once lush woods around his house. He and his wife no longer let their grandchildren play on the lawn because of deer droppings, and three of their neighbors have been diagnosed with tick-borne diseases often associated with deer, he said.
Residents have tried expensive plastic netting, stale perfume, motion-activated sprinklers and products like Deer Scram, a substance that supposedly smells like dead deer to live deer. “They get used to all of it,” said Joseph Bollhofer, chairman of the village’s zoning board of appeals. Even supposedly deer-safe plantings are no longer immune. “They’re eating things they never used to eat,” he said.
Fishkin and Bollhofer said they favored a cull by professional hunters and believed many of their neighbors agreed. But Head of the Harbor prohibits shooting firearms or bows, and trustees have not forgotten the response to a 2015 proposal to lift the prohibition: scores of outraged residents turned out at public meetings, including parents who said they feared for their children’s safety.
“That was an unmistakable message,” said Deputy Mayor Daniel White, at the trustees meeting. Mayor Douglas Dahlgard, in an interview, said a cull this month at Fire Island National Seashore “sounds pretty bloody and brutal.” Dahlgard, who is running for reelection this spring, said those who supported killing deer would have to unseat him first: “It’s not going to happen as long as I’m mayor.”
Expert opinion on PZP is mixed. Allen Rutberg, a Cummings School of Veterinary Medicine at Tufts University professor who is leading the study, said in an interview that “right now reduction of population is not a primary objective for us,” though it could be a side effect: “We know the vaccine works, we know the vaccine works for multiple years, and we know we can reduce populations with it,” he said.
Cornell University natural resources professor Bernd Blossey, who published a 10-year study of deer management strategies in 2019, described PZP work as “a giant appeasement project and some research.” His team found that even a 90% sterilization rate failed to lower deer population. While some of the methods of a professional cull, like shooting over bait or at night, proved successful when continuously applied, he advocates an aggressive approach that includes opening the recreational hunting now permitted in New York State to permit buying and selling of venison, along with the reintroduction of predators like wolves and mountain lions in rural areas.
In Hastings-on-Hudson, a Westchester village of about Head of the Harbor’s size where one of Rutberg’s earlier studies is winding down, former Mayor Peter Swiderski said there appeared to be fewer deer-vehicle collisions and fewer deer overall. But for PZP to work as a solution to the deer problem, he said, it will need approvals from Environmental Protection Agency and New York State environmental officials, and the cost must fall.
His prediction for Head of the Harbor: “Five years down the road, they will see” a deer population drop. “Then they’ll face the same issue we’re facing, which is, can we institutionalize this, is it being done in a sustainable way?”
How PZP works
- When administered to a female deer, the porcine zona pellucida vaccine causes her to produce antibodies that bind to the protein envelope surrounding the egg, blocking fertilization.
- Costs about $500 per deer to administer, plus $100 for annual boosters.
Source: Tufts Center for Animals and Public Policy at Tufts University