Anthony DeNicola, standing next to a sleepy deer on a stainless-steel table, wasn’t used to such surgical luxury. The lights were bright, the imaging equipment was state-of-the-art and, on a recent December dusk, DeNicola’s team settled in comfortably for a long winter’s night of removing the ovaries from white-tailed does.
“It’s going to be hard going back to the old folding card table,” said DeNicola, who is president of a conservation nonprofit that promotes surgical sterilization as a way to control deer populations. He often finds himself working in more rustic conditions. Earlier this year in Fairfax City, Va., he operated in a police garage.
But the National Institutes of Health in Bethesda, Md., was proving to be a dream gig in DeNicola’s effort to promote his technique, which is still considered experimental in some states. Not only did the agency provide a professional veterinary surgical suite, but the research institute immediately understood the procedure’s potential, he said.
While its long-term effectiveness is still unclear, surgical sterilization seems to be gaining popularity in this white-tailed-rich region. The procedure, less invasive than dog and cat spaying, is an alternative to controlled hunting, which provokes opposition from animal-welfare activists, and to immunization, which requires yearly doses of a dart-delivered contraceptive vaccine.
DeNicola has already spayed a herd in a Baltimore suburb, where a population boom has stabilized. And in Fairfax City, he conducted Virginia’s first ovary-removal program when his team operated on 18 female deer in the police garage. The procedures, which cost about $1,000 per doe, are being paid by private donors.
Researchers will not have population numbers until next year, but DeNicola said a similar project in a San Jose neighborhood has coincided with a 40 percent drop over two years in the deer population.
“It’s still really about the science,” said DeNicola, who has a doctorate in wildlife biology. “The more locations we work in, the better we understand the technique.”
The 322-acre fenced NIH campus makes for an appealing field study. A herd of nearly 40 deer lives on the grounds, co-existing with more than 18,000 employees and contractors during the workday. The herd is mostly enclosed, though some wily bucks and does apparently slip in and out, probably through entrance gates.
“I’m sure there is some movement in the wee hours of the morning,” DeNicola said. “That’s how they got in there to begin with.”
In the maddening world of deer management, the free movement of the animals can be a significant obstacle in population control. White-tailed deer do not naturally wander far from their birthplace, but they move in search of food or out of fear.
A recent experiment in sterilizing deer at Cornell University — using tubal ligation — backfired when the reduced birthrate was offset by randy males moving onto campus. The bucks didn’t stop there, researchers found, because the treated does stayed in heat longer than those who got pregnant, creating a group of “buck magnets.”
Under the spaying technique in use at the NIH, females don’t go into heat at all.
DeNicola thinks sterilization could help reduce the number of deer in nearby Rock Creek Park, where sharpshooters cull the herd each year. Deer have proved elusive there, taking refuge in adjacent neighborhoods where hunting is less practical.
They also may have migrated to the 578-acre campus of the National Institute of Standards and Technology in Gaithersburg. There, a Humane Society program has cut the deer count in half since the late 1990s with dart-delivered birth-control vaccines that require a yearly booster, leaving a population of almost 200. Surgical sterilization, while more expensive, is permanent.
At the NIH, agency officials said that deer have been around for years but that the herd’s slow growth became a concern about three years ago as commuters found themselves sharing the roadways with more bucks, does and fawns. A few staffers expressed fear of the animals, especially when the yearly rutting season produced more aggressive bucks.
White-tailed populations have exploded in East Coast suburbs as predators have disappeared and housing developments have pushed into the woods. In the Washington area, that means a lot of federal facilities are now in the middle of deer country.
A spokeswoman for the General Services Administration said it does not keep spending figures for deer control at federal agencies. But it is an expense at many government facilities, including military bases, experimental farms and office compounds. In 2012, the National Park Service approved a controversial plan, including regular hunts, to whittle the deer population in Rock Creek down from more than 70 per square mile to 15 or 20 per square mile.
NIH officials consulted with the Maryland Department of Natural Resources, which recently approved surgical sterilization as a deer-management technique. The NIH alerted staff that female deer would be darted and spayed. With fewer baby Bambis next spring and with a natural mortality rate of about 10 percent, the NIH herd should begin to shrink.
“We had overwhelming support, with many employees applauding what they saw was a humane approach to our problem,” NIH spokesman Bradley Moss said.
And so, over two nights earlier this month, DeNicola found himself stalking the dark Bethesda campus with a dart rifle, worried about being taken for an armed intruder. He avoided passing any window where he might be seen and wore no camouflage.
“You just want to look like a working suburbanite,” he said. “You don’t want to be ominous in any way.”
DeNicola, who has darted close to 4,000 deer during his career, methodically hit one female after another, knocking them out for about 90 minutes. The darting was timed so that the last deer to go down would be on her feet before morning commuters began pouring through the gates.
“We didn’t want a bunch of calls that deer were stumbling all over the place,” DeNicola said.
After each darting, the females were taken by pickup truck to the NIH’s veterinary operating suite. There, DeNicola’s vets demonstrated their deer-spaying technique to a team of NIH vets. But while NIH vets can do the operations next year, no one thought it would be a good idea to send them out on the crowded campus with tranquilizer rifles. “We decided I would still capture the animals,” DeNicola said.
They put radio collars on 10 does for future monitoring, tagging each with a warning not to eat the venison because of the tranquilizing agents. (The meat is safe again after 45 days, DeNicola said). The team managed to capture all but two of the herd’s females.
“Don’t worry,” DeNicola pledged, “we’ll get those next year.”