Deer cull report doesn’t repudiate 4-posters

A just-released study focusing on managing white-tailed deer in suburban environments in no way repudiates the efficacy of 4-poster units, according to one of the report’s authors.

“We are not shying away from 4-posters,” said wildlife specialist Dr. Paul Curtis of Cornell University. “I still see these devices as just one possible component of an integrated deer management program in suburban areas [statewide].”

The reason the report doesn’t mention 4-poster units is its objective was to look specifically at means of reducing deer numbers and the negative impacts the animals have on plants and in causing vehicle collisions, he said.

What’s more, the New York State Department of Environmental Conservation so far has authorized use of 4-posters only on Long Island, Dr. Curtis said.

Other places upstate that have sought approval for the units have been turned down because DEC law, waived on Long Island, prohibits the feeding or baiting of deer. “To date, the DEC has been inflexible” about registering use of the units in other areas of the state, he said.

Four-poster units are baited with corn and as the deer eat, their necks are coated with the tickicide permethrin.

“Tick densities and the potential for tick-borne diseases, are an impact indicator we want to examine in the future if we can find research funding to support this,” Dr. Curtis said.

The current study, produced in cooperation with the United States Department of Agriculture, Cornell Cooperative Extension and Cornell University was conducted in Ithaca, New York and surrounding areas, all on Cornell-owned property.

As for the culling program, Dr. Curtis said he’s “not certain” it’s possible to “get deer densities low enough for tick populations to crash.” It’s why communities typically take a multi-pronged approach to the problem, he added.

Cornell’s study took a two-pronged approach to reducing the deer herd — sterilization and hunting.

Sterilization was employed using tubal ligation and ovariectomy around the campus where student population and building density would preclude hunting.

“Earn-a-buck hunting” on university-owned land relaxed rules that previously required hunters to take two anterless deer, generally female, before they were allowed to shoot a buck. That was changed to allow hunters to shoot a buck for every anterless deer they took. Hunters used bows, regular firearms and muzzle loaders. Radio collars and infrared cameras were used to track deer.

Among the conclusions drawn were that surgical sterilization as the sole tool for reducing high density deer populations is very expensive and not sufficiently effective, even when carried out over a 10-year period. Similarly, use of contraceptives has also been shown to be prohibitively expensive and difficult to administer.

“Those communities that started with sterilization only, have subsequently either embraced lethal deer management or allowed deer populations to persist at undesirable levels,” according to the report. It advises against using sterilization or other fertilization methods without also implementing lethal controls to cull herds. And unless a community has the money to bear the cost of sterilization for 90 to 95 percent of its female deer, the report recommends that the methodology not be implemented at all.

While the allowances in place for culling deer allowed hunters to take up to two anterless deer per day, researchers found that most hunters wanted to take only two or three deer per season, the study said. That prompted the conclusion that it would be necessary to identify many more hunters to tackle the job than were currently stepping forward.

That study’s findings on how many deer a hunter takes is similar to the situation on Shelter Island, where hunter Beau Payne has told the Deer & Tick Committee that normally he and his fellow hunters only kill deer for meat for themselves and their friends.

What works, according to the study is a bait and kill method.

Other alternatives — regulated commercial hunting and capturing and euthanizing are illegal in most places and tend to result in community court challenges, according to the study.

This past year, only Southold on the East End, engaged in a Department of Agriculture program allowing sharpshooters to hunt deer. Results were poor and largely blamed on a late start and local opposition to the use of sharpshooters. Other East End communities backed off from the USDA sharpshooters early on, largely because of local opposition.

Nonlethal controls such as growing non-native plant species has been found detrimental to areas where it was tried and use of repellents has proven ineffective as a permanent solution, the study said.

“Overabundant suburban deer populations continue to challenge natural resource agencies and local communities,” the Cornell study concluded. “Communities will need broad-based support and the political will to implement lethal deer control.”
The full Cornell report is available online at wildlifecontrol.info/deer/Documents/IDRM_12_5-2014.pdf.