On the Ground, Counting Deer
Aaron Houston for The New York Times
A deer freezes in the spotlight during a count conducted at South Mountain Reservation.
DARKNESS was falling and people were settling down in their homes for the night when Susan Predl, who was just starting her workday, drove her van into the wilds of the South Mountain Reservation here.
In the van were an assistant, Amy Schweitzer, and some important tools — two powerful spotlights, a laser range finder and a notebook for jotting down observations. Ms. Predl, a senior biologist with the New Jersey Department of Environmental Protection, was about to count deer.
The 2,047-acre reservation, spread through Millburn, Maplewood and West Orange and owned by Essex County, had been overrun by deer for years. Last year the county authorized its first hunt organized to cull the herd, and over nine days in January and February sharpshooters stationed in trees killed 213 deer. The controlled hunt in this densely populated area has spurred controversy among residents and people who consider hunting cruel, who have urged the county to find other ways to control the deer population.
But now, weeks later, in the relative calm after the hunts, it was Ms. Predl’s task to estimate the number of deer remaining and help the county formulate plans for next year.
This was actually her seventh run this season at formulating a census, using a method called distance sampling. During six previous trips, Ms. Predl and an assistant had scanned the woods with spotlights and spotted from 19 to 40 deer, at various distances from the van. Feeding the numbers into a software program, Ms. Predl calculated the reservation’s current deer density at 29 to 35 deer a square mile. The night’s results would prove comparable, showing that the South Mountain Reservation still had too many deer. And this was taken a month before the surviving females would start giving birth.
Ms. Predl’s rides through the quiet reservation — off limits to humans after dusk — provided a quiet counterpoint to the noise of the protests and hunts.
For years, anti-hunt forces staged demonstrations urging officials to find nonlethal alternatives to thinning the population. Sometimes, they hired lawyers to make their point. The county listened and experimented with a number of costly options, including an effort to trap the animals and ship them out of state.
One such project involved sending the deer to a farm in upstate New York, but the “farm†turned out to be a slaughterhouse, and embarrassed officials halted transports. The deer, meanwhile, multiplied, in this, one of the last open areas of a congested county.
In September 2007 Joseph N. DiVincenzo Jr., the county executive, finally announced there would be a hunt. “I don’t like hunting at all, but in this situation there’s no alternative,†he said. Protesters demonstrated on Northfield Avenue in West Orange, holding signs saying, “Please don’t turn South Mountain into the killing fields.†But when the hunt actually started on Jan. 29, it drew only a handful of demonstrators.
“It’s a tough emotional issue, but the majority of people realize something has to be done,†Ms. Predl said before starting her final inspection trip. “I think what helped Millburn officials make their decision was a woman suffering terribly from Lyme disease.†The disease is caused by bacteria that are spread by tiny, infected deer ticks.
Counting deer is an imprecise science, and yet so much rides on the results, namely whether and where the county authorizes future hunts. On April 2, Essex County conducted an aerial survey by a helicopter with thermal infrared sensors. That method is expensive, but some believe it yields the most accurate count.
Ms. Predl isn’t sure. “There really isn’t a preferred method of estimating the deer populations out there,†she said.
By day New Jersey’s white-tailed deer are nearly impossible to spot, given their excellent camouflage of brown and gray. At night though, caught in the glare of a three-million-candlepower spotlight in a forest still bare of leaves, it’s a different story.
“When you shine the spotlights, their eyes almost glow back,†said Ms. Predl, a 25-year veteran of the Fish and Wildlife Division. “In the dark you’ll see pairs of eyes looking back at you. Up here, besides the deer, we’ve seen a lot of raccoons and red fox here. One night I think I saw a coyote and a screech owl. Each animal has eyes that glow a slightly different color. It’s kind of amazing and fun.â€
For two-and-a-half hours she drove the van through the deserted park at about 10 miles per hour, holding a spotlight out the driver’s window with her left hand and steering with her right. Ms. Schweitzer, a state wildlife technician, held the second spotlight out the passenger-side window.
“There’s our first Bambi, no, wait, there are three of them,†said Ms. Schweitzer, picking up the greenish glow of three pairs of eyes 60 yards away.
So it went, over rutted roads near long-neglected picnic groves and campgrounds, and on busy perimeter roads like South Orange Avenue. There, as speeding cars and a New Jersey Transit bus whooshed by, Ms. Predl put on her hazard lights and drove while Ms. Schweitzer peered into the woods. The van posed a strange sight. Some drivers slowed down to gawk. “Are you all right?†one asked.
At the end of the night Ms. Predl headed for home, in Warren County, eager to tabulate her findings.
Essex County officials plan another hunt, and have embarked on a program to restore South Mountain’s ravaged understory with plants and build “deer exclusion areas.â€
The reservation will never be entirely clear of deer, nor should it be, said Dan Bernier, a Union County parks official who is a consultant for Essex. Union County has used hunts to thin deer from its largest park, the Watchung Reservation, since 1999 and estimates it now has 20 deer a square mile, close to the ideal number, he said.
“You know you’re where you want to be, when you get it down to a point where people can grow tulips and tomato plants, and you don’t end up with a lot of deer carcasses on the road,†Mr. Bernier said. “We’re also seeing the beginnings of a recovery in the reservation. Shrubs have begun to leaf out in the area four feet or lower from the ground.â€