How many whitetail deer are on the South Fork?
The question seems reasonable, and the answer fundamental to making decisions about managing deer populations in the region.
But, despite recent discussions about controlling the deer population in East Hampton and Southampton towns, it’s simply not clear what that population is. Counting deer is an inexact science—it’s not possible to tally each and every one—and estimates vary depending on the type of survey being used.
Southampton Town hasn’t tried to count its deer, but East Hampton has—and the results have provided ammunition for both pro- and anti-culling contingents.
An aerial survey in 2013 reported 877 deer throughout East Hampton Town. A distance sampling survey in 2006 estimated the population as 3,293. Some argue that the difference shows that the population decreased significantly. But the town planning director, Marguerite Wolffsohn, is among several who say the two surveys simply cannot be compared.
Flyover surveys can miss deer hidden by trees, while distance surveys, which extrapolate an overall number based on sample sections of habitat, can fail to account for the movement and irregular dispersion of deer. On Shelter Island, for example, an extrapolation survey estimated 1,868 deer, while an aerial survey reported 131. Cornell University’s wildlife specialists estimated the true number of deer on the island to be between 600 and 800.
Time of year also will make a difference, according to Mike Scheibel of The Nature Conservancy, who manages the Mashomack Preserve on Shelter Island. Populations peak around Memorial Day, after the fawns are born, then taper off and bottom out after hunting season in winter.
“There’s fewer today than there were this time yesterday morning,” as deer fall to motor vehicles, hunters and other mortal encounters, until new ones are born the next spring, Mr. Scheibel said.
According to the Department of Environmental Conservation, deer nearly vanished from New York State in the mid-19th century because of over-hunting and loss of habitat. The population rebounded after hunting was restricted and peaked at an estimated one million statewide between 2000 and 2002.
Hunters themselves topped out statewide in the mid-1980s. Their number has since been declining, according to the DEC’s deer management plan for 2012 to 2016.
The DEC estimates roughly 25,000 to 35,000 deer on all of Long Island, according to spokeswoman Aphrodite Montalvo, who could not narrow that number down by county or township. Deer need a habitat with shrub and cover, and assuming about one-third of Suffolk County to be too developed to be hospitable, the DEC estimates that the remaining habitat supports an average of 35 to 50 deer per square mile. Ms. Montalvo called that “a conservative estimate” based on density surveys in East End towns.
She did not have comparative estimates for 10 years ago, but said, “It can be safely assumed that deer population numbers have increased based on deer harvest numbers and westward deer migration.”
The deer population remains fairly dense as far west as the pine barrens, according to Paul Curtis, a Cornell Cooperative Extension wildlife specialist and coordinator of the wildlife damage management program, who said there are deer in eastern Nassau County as well.
Counting deer is expensive and difficult, with varying degrees of confidence in the results. “Really, it’s the impacts to people that are more important than the actual number of deer,” Mr. Curtis said, making a point echoed by Ms. Woffsohn and Mr. Scheibel as well.
When it comes to deer management, the DEC assesses the extent of damage that deer inflict more than how many there are, Ms. Montalvo said.
Quantifying problems like motor vehicle accidents, tick-borne disease and damage to the ecosystem is more productive when making decisions about how to manage deer, according to Mr. Curtis. “That way you’ve got measurable goals.
“People just get hung up on [numbers],” he said. “It’s clear: If there weren’t too many deer, people wouldn’t be talking about these issues.”
State Farm Insurance ranks New York 24th out of the 50 states in terms of the likelihood that a vehicle and a deer will collide, an uptick from the previous year, when it ranked 25th, during a period when the likelihood nationwide went down. New Yorkers have a 1 in 157 likelihood of striking a deer with a car, according to the insurance company, which does not break down the state into smaller geographical areas.
Southampton Town Police recorded 185 motor vehicle accidents involving deer in 2013, with three people injured. There were 192 in 2012, with three injuries; 177 in 2011, with five injuries; 177 in 2010, again with five injuries; and 125, with four injuries, in 2005. There were no human fatalities in those collisions.
The numbers weren’t much different 13, or even 18, years ago: there were 113 accidents involving an animal in 2000, and 135 in 1995. At the time, Southampton Town Police did not distinguish motor vehicle accidents involving deer from those involving another kind of animal, such as a dog, although Lieutenant Michael Zarro said it was his guess that the vast majority of those accidents involved deer.
In East Hampton Town, 81 motor vehicle accidents involving deer were reported in 2013; 101 in 2012; 106 in 2010; and 108 in 2005. According to the East Hampton Town Police Department, there were 70 in 2000 and 68 in 1995. The number of people injured in those accidents was not available.
According to the East Hampton Town Deer Management Plan, the town’s Highway Department removed 334 deer from the roadside in 2008 and 231 in 2009, with another 200 estimated to have been removed from state roads in each year.
Whitetail deer are often implicated when it comes to Lyme disease, which after all is transmitted by black-legged ticks, also known as deer ticks. According to the Centers for Disease Control and Prevention, however, the role deer play in the spread of Lyme disease to humans is not entirely clear.
Ticks become infected by feeding on infected animals, such as mice and other small mammals, early in life. They then can transmit that infection to other, uninfected animals like humans in the following year. Deer themselves cannot become infected with the Lyme disease bacteria, according to Kiersten J. Kugeler, an epidemiologist at the CDCP’s Division of Vector-borne Diseases.
In adulthood, however, most ticks feed on deer, as well as other medium to large mammals, which is where they get their “final blood meal, before dropping off the deer and laying eggs that will hatch the following summer into new, uninfected larval ticks … and the cycle begins again,” Ms. Kugeler said.
Deer fuel tick reproduction by providing a meal to the adults, as well as helping to spread ticks so that eggs can be laid in new places where the adults dropped off the deer, the epidemiologist said.
“There have been several studies that have examined the role of deer population reduction on abundance of black-legged ticks, and with mixed results, Therefore, the jury is still out on whether deer population reduction should be considered a Lyme disease prevention measure,” she concluded in an email.
“Of course, deer overpopulation can be a problem for other reasons including crop damage and motor vehicle accidents,” Ms. Kugeler added.
“Deer are one of those species that are a driver of the ecology,” said Mr. Scheibel of the Mashomack Preserve, whose staff have been studying the effects of overbrowsing with “exclosures” protecting small sections of the forest from hungry deer. “They can have a profound effect not only on plants but on other animals.”
The East Hampton Town Deer Management Plan contains photos of what some call “the Hamptons haircut”—hedges mowed back roughly the height of a deer, and roadsides stripped of saplings and wildflowers. Over-browsing takes a toll on biodiversity by creating a parklike forest without the understory that certain plants, insects and animals need to survive, both the management plan and Mr. Scheibel point out.
“Certain birds, certain small mammals … [like] voles, rabbits, shrews need protective cover,” Mr. Scheibel said. “Oven birds, black and white warblers tend to nest in those lower [areas].”
“These are things that the public in general doesn’t see,” said Mr. Scheibel, who was in the process of reading Al Cambronne’s book, called “Deerland,” which notes that many people today “don’t have a good idea of what the forest should look like” anymore.
In an attempt to discover “the way it might more normally look if we had a number of deer that were not having such a profound effect,” Mashomack removed them completely from the equation by creating exclosures, beginning in 2000, as well as by continuing to thin the herd outside them with hunting, aiming for a density of about 20 deer per square mile.
Indicators such as seedlings and saplings, flowering herbaceous plants and vines have been monitored for 13 years now. “When we started, there were essentially no saplings,” Mr. Scheidel said. “You have a situation here in 2000 where we had a fair number of small seedlings, 2, 3, 4 inches in height … they would be browsed off and never reach the next stage of life, so there’s this void: fairly small trees and large trees in this particular forest that’s close to 200 years old, and nothing in between.”
They had tried thinning some areas of the nearly 2,000-acre preserve at first, to see if more direct sunlight would help the lower plants, but they were still not getting the regeneration they’d hoped for.
Now, wildflowers like woodland asters that had not been seen for some time are beginning to return, seedlings are growing into saplings and a tree called hophornbeam, which had not previously been seen at all, has sprung up.
“Phenomenal things are happening in there that we would never have envisioned,” Mr. Scheidel said of the exclosures. “Once they were given protection from the deer, they just rebounded.” It was astounding, he said, that there were still seed sources in the ground.
Even outside the exclosures, he said, “we are making some progress” in reducing forest damage, in particular through recreational hunting and the use of deer damage permits, “In the forest, deer browse is down significantly from 10 years ago,” he said, “so there’s some reason at least for optimism here.”
Still, he said, the number of deer continues to be high on the preserve, which they can enter from elsewhere on the island or even by swimming. As long as they damage the preserve, it doesn’t matter whether there are 250 or 100 of them, he said: “My pat answer for many, many years is, there’s too many.”