Roger Schaeffer used his right hand to shield his eyes from a steady barrage of snowflakes Sunday as he strained to look across the open field.

"There they are," the Columbia resident said, pointing to a herd of deer.

Nearly three dozen bucks and does were sprinting through a swamp in Muddy Run Recreation Park, heading toward a corner in the park's fence along Route 372 in Martic Township.

With a line of people slowly approaching them, the deer had no choice but to run toward Schaeffer's team of men and women.

"Here they come," Schaeffer called out to his crew stretched out across the field. "Get ready to count."

About 70 volunteers turned out at Muddy Run on Sunday afternoon to participate in the annual census to estimate how many deer are living on Exelon Corp.'s 800-acre property in Martic and Drumore townships.

According to park manager Dave Byers, 230 deer were counted Sunday — 179 does and 51 bucks.

That's up from the 175 counted last year.

To count the deer, the volunteers broke up into three groups and systematically walked in lines through the entire park property.

"I have to thank everyone who came out here on behalf of Exelon, because we couldn't do this without the volunteers," Byers said.

Volunteers were instructed to count only deer that passed by their right side to avoid counting the same deer multiple times.

Any deer with one or two antlers on its head was counted as a buck, while those without antlers were counted as does, even though at this time of year some bucks may already have shed their antlers.

Bucks shed their antlers each winter and then grow a new set during the summer.

Ed Radesky of Willow Street braved the sub-freezing temperatures and the falling snow Sunday to participate in the deer count for the first time.

"I figured I'd come out and see some deer," he said. "You don't see too many out in the wild any more."

Ben Fisher of Intercourse figures he's volunteered with the count five times, including the past three counts.

"It's a nice day — something to do outside," he said.

The annual count is the best way park officials can estimate the property's resident deer herd, said Schaeffer, who has helped organize the count for the past 20 years.

"The park can only support so many deer," he said. "This is how they monitor the population."

When he first started volunteering at the count, Schaeffer said there were nearly 500 deer in the park.

That number declined slowly over the past 20 years, but then took a sharp drop last year to 175 from about 250 the year before.

Schaeffer said he's not sure what caused the decline, but named a number of possible factors, including hunting pressure inside the park, predation by coyotes and deer leaving through holes in the fence.

"It's probably a combination of things," he said.

In the past, a series of three controlled hunts was held inside the park each year.

One was open only to handicapped hunters, another allowed only archery hunters to participate and the third was open only to hunters using flintlock muzzleloaders.

Those hunts annually netted about 40 deer, according to Byers, who oversees the hunting in the park.

In the wake of last year's low deer count, Byers discontinued all hunts for the 2008-09 deer season.

He said he expects the closure to last at least another year — and possibly two years — to allow the herd to rebound.

"After that, we'll take a look at things and see what we want to do from there," he said.

Byers said he would like there to be about 350 deer in the park before hunting resumes.

Email: preilly@lnpnews.com