Three deer stand frozen in a sunlit clearing at the Middle Patuxent Environmental Area, watching a visitor who appears around a bend in the path. After a few moments, two turn away and head for the woods, while the one in front — a slender creature standing over 3 feet tall — won't take its eyes off this late-morning intruder crouching some 45 paces away.

About a minute goes by before the deer turns and bounds into the trees, its white tail flashing. The clearing by a picnic area is left to the grass, breeze and birds.

The human visitor in this instance is armed with only a pen and notebook, but in a few weeks, otherts will come with bows and shotguns as Howard County begins the annual whitetail deer hunt here and at five other parks. From dawn until noon on 30 days between early October and early February, these six county parks will be closed to visitors and opened to some 130 hunters chosen by the county Department of Recreation and Parks, which runs the program and just announced the hunt schedule.

If this season's hunt goes as others have in the past, the hunters will kill about 180 deer in those 30 days, mostly does but some bucks as well. The effort is meant to maintain ecological balance between the deer and their immediate surroundings, and to protect trees and other park vegetation.

Official estimates show that the program that began in 1998 has so far fallen short of reaching what is considered an ideal deer-to-square-mile ratio. When the hunts began, there were about 100 deer per square mile in the parks, says Philip C. Norman, who runs the deer management program, and now there are between 35 and 50. The ideal number, he says, would be 15.

Animal welfare advocates say the effort falls short in another respect, as they insist this approach to managing the deer population causes the animals needless suffering.

Both Norman and Brian Eyler of the Maryland Department of Natural Resources say benign ways of controlling deer populations are too expensive or impractical, or both.

Eyler, the DNR's deer project leader, says the deer contraceptive vaccine GonaCon was approved for use in Maryland two years ago, but no one has asked for a permit to use it. He says the vaccine is not expensive, but it has to be injected into each animal, and that runs into money.

"The drug itself is cheap, but it's the manpower, it's the labor," Eyler says. The price, he says, can be "easily $500 per deer."

Several deer management projects around the country have tried capturing and sterilizing female deer, but such efforts have been conducted on only a small scale. Eyler said the cost can run from $800 to $1,300 for each animal. Two projects conducted since 1996 in Montgomery County involved shooting deer with darts loaded with contraceptives, but the drugs have to be readministered every few years.

Enid Feinberg of Baltimore County, the volunteer president of Wildlife Rescue Inc., helped arrange an effort to surgically sterilize female deer near the Loch Raven Reservoir. The animals are lured in with food, shot with a tranquilizer, carried to an operating table where they're spayed, then returned to the outdoors.

The privately financed pilot project has sterilized 50 female deer. Feinberg says the cost can be trimmed by using more volunteers.

Both Feinberg and Ann Selnick, the former president of Animal Advocates of Howard County, say that even if Howard County rejects such nonlethal methods as too costly, it could take a more humane approach to killing deer. Both say the county could use sharpshooters rather than conventional hunters, arguing that they would be better able to kill the animals quickly without causing them undue pain.

"I don't think animals should suffer any more than they have to," Feinberg says. She sends by email several photographs showing deer that survived being shot with arrows.

In one instance, Feinberg says in an email, "we received a frantic, hysterical call about a deer in a neighborhood running around with an arrow in its head coming out of her mouth." A deer injured this way was found dead two weeks later, and Feinberg took pictures of it.

Norman says all the hunters who take part in the program are screened by a three-member panel of agency employees. The applicants are questioned about the rules of the county program as well as their hunting experience and knowledge. Norman says they're asked how they would handle encounters with residents and animal welfare advocates who might be protesting the hunt.

Hunters are required to present a state-approved certification of shooting ability from a range, Norman says. Norman says the county's standard for bow hunters is more strict than the state's, as archers have to show they can hit a 6-inch-diameter target three of four times set at distances between 10 yards and 25 yards. Under the county program rules, archers cannot shoot from more than 25 yards away from a deer, shotgun hunters from no more than 80 yards, Norman says.

Along with the hunters — who pay a $15 application fee and $50 registration fee once they're accepted into the program — the county's deer management approach also includes a team of three sharpshooters who are county employees, including Norman himself. The sharpshooters, who have been part of the program since 2004, operate between December and March in areas "where a managed hunt is not feasible" because they're too close to homes or schools, he says.

While rifle hunting in the county is barred by state law, Norman says the sharpshooter program is conducted in cooperation with the state DNR. Working at night, the sharpshooters use bolt-action and semiautomatic rifles fitted with noise suppressors.

Asked why the county doesn't use sharpshooters alone, Norman says it would be too expensive and complicated to cover an expanse such as the 1,000-acre Middle Patuxent Environmental Area. The hunt is also conducted at Alpha Ridge, Blandair, David Force, High Ridge and Schooley Mill parks.