A newly published final report on the five-year 4-Poster tick management study conducted on Shelter Island finds that tick populations significantly declined, for the most part, in areas where the deer-feeding devices were set up compared with the North Haven control site, where no 4-Posters were used.
The state Department of Environmental Conservation announced Monday that the exhaustive, complex and highly detailed scientific report on the study, which began in 2007, has been completed and is now available online.
4-Posters are plastic feeding stations affixed with four rollers on vertical posts that apply a solution of the common pesticide permethrin to the heads and necks of deer as they feed on corn. Ticks concentrate heavily in those areas of the deer, which are the primary hosts for the black-legged or deer tick, the dog tick and the Lone Star tick, which carry diseases includes Lyme, babesiosis and erlichiosis.
New York State has never approved permethrin for such a use, and it forbids deer baiting because it could spread chronic wasting disease. For those reasons, the DEC initially opposed any 4-Poster experiment. For the study to happen at all, it took a letter from Shelter Island resident and former Governor Hugh Carey to then-Governor George Pataki asking him to tell the DEC to relent as a matter of public health. The DEC soon began talks with citizen groups and public officials to develop a comprehensive plan for conducting and funding the study.
The study was conducted by Cornell University and Cornell Cooperative Extension in association with many other entities, public and private, including the Town of Shelter Island. The comprehensive final report was prepared by Cornell University and its Cooperative Extension service.
The program received $1.6 million in funding from sources including the state, county and town as well as private interests. It used 60 4-Posters in key sites on Shelter Island, which is continuing a limited 4-Poster program on its own using 15 feeding stations.
The study’s data, said project director Vincent Palmer of the DEC, “will enable DEC and DOH [the state Department of Health] to make fully-informed decisions with regard to the role this technology may play in reducing tick populations and the human incidence of tick-borne diseases.”
Some of the report’s findings have been previously announced locally and do not come as a surprise on Shelter Island, where the program was once a hot topic. Intense controversy over the experiment died down gradually after the study had been underway for a year or two.
A group of residents there in 2005 and 2006 lobbied town, county and state officials for the chance to try 4-Posters as a way to cut the local tick population and reduce the incidence of tick-borne disease. The device had been developed by scientists working for the U.S. Department of Agriculture in the early 1990s to reduce tick infections on grazing cattle in the Southwest.
Locally, hunters and some environmentalists feared the permethrin would contaminate the environment as well as the Island’s deer herd, threatening hunters who handled or ate them. Supporters argued that broadcast yard applications of permithrin solutions by commercial tick-spraying companies had already introduced the chemical into the environment.
The study did find permethrin on some deer hides and in neck muscles in both the treatment and control areas. No traces were found in any deer haunches, which were also tested for residues. The study cautions that the use of 4-Posters could be problematic in areas with chronic wasting disease, which biologists believe may be spread by deer coming in close contact, as they could do at a feeding station.