You have to wonder, What are the deer thinking? One minute, they’re standing around in a Fairfax City park with their pals, then they feel something sharp in their hindquarters. Then they wake up 90 minutes later and their bellies are shaved and something feels different inside. They’ve been spayed.

Fairfax City’s program to try to control its deer population by sterilizing the does, rather than killing them, began Friday night and will continue for the rest of this week. Overseen by Anthony J. DeNicola, a wildlife biologist with decades of deer experience who runs White Buffalo Inc., the program was aided by a raft of volunteers, many with Maryland’s Wildlife Rescue, who helped DeNicola transport the deer or helped veterinarians Jeffrey Newman of Fairfax Station and Steve Timm of Wisconsin with the ovariectomies, or aided DeNicola in returning the does to the woods. Fairfax City police helped DeNicola track and hunt the deer through the six-square-mile city’s various open spaces, staying away from private property and not using spotlights or helicopters.

It’s the first time this has been tried in Virginia. By the end of day three, the group had “darted,” spayed and returned 11 female deer. DeNicola is hoping to spay and tag at least 20 does by the end of the week, and he’s well on the way. He has also placed 20 motion-activated cameras around the woods to get a sense of how many deer are untagged and monitor the population, which he has estimated is about 50 to 75 total deer. He is running similar programs in Baltimore County, Cayuga Heights, N.Y., a small community in San Jose, Calif., and Town and Country, Mo. The cost of the Fairfax City program is estimated to be about $50,000, and is being paid entirely, for the first two years, by donors to Wildlife Rescue.

I tagged along on Sunday night/Monday morning, and the process seemed humane and largely painless for the deer. DeNicola said he saw a deer he had tagged early Sunday morning back out and about on Sunday night, munching on vegetation with her fawns, though now she has tags on each ear and a tracking collar around her neck, so they can monitor her occasionally and perhaps learn how she dies. One thing DeNicola found interesting:  none of the 11 does he’s caught so far were older than 6 1/2 years old. That may mean  they are dying younger in Fairfax City for unknown reasons, since there’s no hunting in the city and they’ve only had about 20 reported car-deer fatalities since 2006, Sgt. Michael Duncan said.

DeNicola uses a gun armed with tranquilizer darts, and rides with a Fairfax City officer through the parks, shooting the darts out the passenger side window.  The officers are also on hand to make sure no people are in harm’s way. The darts have a tracking device in them so after he shoots one, he can find the shot deer in the dark.

Around 11 p.m. Sunday, DeNicola was sitting quietly in Van Dyck Park and saw some deer on the wide open soccer field. Though he’d already darted and tagged nine deer, the word apparently had not gotten around among the deer to maybe not hang out in wide open spaces. DeNicola successfully darted two more. He found the first one, helped load it into a volunteer’s van, and drove it the short distance to Fairfax City police headquarters, where surgical tables had been set up in the sallyport.

Newman, who works for Caring Hands Animal Hospital vet clinics and also runs a neutering program for cats in this area, was trying out deer spaying for the first time. He said he’d studied the protocols used, and felt that with the steps taken to minimize pain through anesthetics and antibiotics, with almost no post-operative infections, “I’m impressed with it. These deer are going to be fat and happy.”

He also had help from Timm, who works with DeNicola and has assisted vets on dozens of such operations. He said he and DeNicola had been pondering whether sterilization would actually work, since vaccines still are not effective, and so far this seemed promising. In areas where the program has begun, deer population seems to be dropping by about 10 percent per year, but it’s still too early to judge. DeNicola said one of the things which has to be monitored is whether deer from adjacent areas move into areas where the sterilized deer have been slowly dying out. He said deer typically do not move like that, either because they don’t know that an area is less populated, or the area is still populated enough to keep new groups out.

I followed DeNicola back into the Van Dyck Park woods to find his second deer. He had a radio antenna and an earphone, to determine where the doe had fallen by the strength of the “ping.” We moved through some light brush and found her in no time. He checked to make sure she was immobilized, then loaded her into a van and back to the police station we went.

By this time, Newman and Timm had finished their third ovariectomy of the night. DeNicola loaded that deer, number “10” for the rest of her life, into the van and returned her to Van Dyck. There, he administered a “reversal” drug which negates the effects of one of the sedatives. We waited to see if it took effect, but did not stay around to see her return to full consciousness. “We don’t want to freak them out any more than we already have,” DeNicola said.

In addition to being very funny, DeNicola is quite knowledgeable about deer and  concerned about their welfare, and also a very good tracker and darter. He is agnostic on the whole issue of killing vs. sterilization, he just wants the research to judge which one might be more effective, and he’s willing to do both. This program was approved by the Virginia Department of Game and Inland Fisheries as a research project. DeNicola also said he has a friend with a fixed-wing aircraft and an infrared camera who was going to fly over 27 Fairfax County parks and try to get a sense of the deer population there.

Fairfax County has been “culling” (or “killing”) deer for years, and some still think that’s the way to go. Kevin Rose, a certified ecologist with the state game department, said that, “Sterilization does not immediately reduce the population, whereas hunting does have an immediate impact. With sterilization, the current population will remain high until natural mortality may decrease the population over time. This means that individuals complaining of damage will not receive immediate relief of damage caused by deer, but will have to live with inflated populations until the deer begin to die off. This assumes that the project is a success and this experimental method does reduce the population.”

Rose added, “At this time, the use of sterilization to manage deer in open populations is not a proven method. The program in the City of Fairfax is a research project to examine the use of these techniques. It is important to recognize that distinction between research into experimental methods such as sterilization and management using proven methods such as hunting and sharpshooting. The Department of Game and Inland Fisheries would not have issued a permit to allow an unproven technique to be implemented as management.”

DeNicola said that, for the government, “It’s mostly a political game of ‘Who Squawks the Loudest?’ Whether it’s the farmers, or the hunters, or the homeowners, the government just collects the data and responds who the loudest squawkers.” For now, Fairfax City is simply trying to find out what works, and is trying this approach before its deer population gets out of control, rather than after.