Town official: Too early to draw conclusions from recent tick data

In two successive presentations, town Animal Control Officer Beau Payne outlined progress in gathering data he hopes will eventually shed light on what’s working and what’s not to control Shelter Island’s tick population.

Reporting first to the Deer & Tick Committee on December 7 and then to the Town Board on Tuesday, Mr. Payne cautioned not to draw conclusions from early data since it’s too soon to see trends that would be meaningful.

What’s evident from the charts he produced is that tick drags conducted in various areas of town show a slight increase this year from previous years, but while that’s true for all six sites scattered around the Island, it’s not the case for drags conducted at Mashomack Preserve.

Why not?

“I don’t really have an answer for that,” Mr. Payne told Deer & Tick Committee members when asked about the discrepancy.

He’s working to set up more sites where drags can be done, particularly in areas at a distance from where 4-poster units are deployed during spring, summer and fall months. A number of studies in other municipalities have shown that the 4-posters — feeding stands that brush deer with a tickicide, permethrin — appear to have little effect in lessening ticks in areas more than 300 hundred yards from the units, said Deer & Tick Committee member Marc Wein.

When the Cornell University-Cornell Cooperative Extension pilot program operated here between 2008 and 2010, there were 60 4-poster units deployed throughout the Island. This year, there were fewer than 40 units, including those at Mashomack Preserve.

Some critics saw the 60 units as overkill for what was needed here, but others have argued that more than 40 units is necessary to have a major impact on tick drag results.

Mr. Wein — once a proponent of the units, who has switched to calling for more effort and money to cull deer herds — said tick drag results in North Haven that haven’t used 4-posters, and  those on Ram Island, where there are fewer units, haven’t been much different than areas of Shelter Island where units are deployed.

Mr. Payne said he couldn’t draw conclusions yet, but agreed there’s a need for more tick drags to be conducted at sites a suitable distance from the 4-posters.

“We’re doing the best we can,” Committee Chairman Mike Scheibel intervened. “It takes time.”

Shelter Island officials have been encouraging a follow up study by Cornell on the Island to determine both the long-term effectiveness and safety of permethrin. Cornell’s response has been more money is needed to conduct a follow up — money the town doesn’t have and neither Suffolk County nor New York State is is eager to fund, according to Councilman Jim Colligan, liaison to the Deer & Tick Committee.

Because of drought conditions this year, Mr. Scheibel said he had anticipated fewer ticks when the drags were conducted, but that hasn’t been the case.

There has been an increase in the use of corn used to attract deer to the 4-posters, Mr. Payne said. But he dismissed suggestions that animals other than deer were consuming large quatitiies of the bait.

A family of raccoons isn’t going to eat as much corn as one deer, the animal control officer said.

Vehicle collisions with deer are up slightly this year, Mr. Payne reported. But Police Chief Jim Read said that’s an insignificant number that wouldn’t shed light on just how many deer are on the Island.

Mr. Payne and committee member Dr. James Bevilacqua have also embarked on a venture with Island doctors and the Shelter Island Pharmacy to begin to track prescriptions for Doxycycline, the most frequently prescribed drug for Lyme disease.

Numbers collected so far in this project, beginning in 2006 before 4-posters were used on the Island, were high and declined sharply by 2009, one year into the pilot 4-poster program. Through the years since then, they have fluctuated, but always at much lower levels than they were since 2006.

Again, Mr. Payne, joined by Dr. Bevilacqua, urged that no conclusions should be drawn yet. Mr. Payne noted there have been changes in doctors on the Island and also in protocol where once Doxycycline was given to patients diagnosed with Lyme Disease. But now, it’s being given to patients who have been bitten by ticks even if they haven’t been confirmed to have Lyme.

Also, other drugs are sometimes being prescribed for Lyme, the two men said.

Dr. Bevilacqua said comparing the numbers through the years isn’t like comparing apples to oranges, but more like tangerines to oranges. But more information would be needed before a conclusion is reached whether tick-borne diseases are declining or increasing, he said.