By KIRSTI MAROHN
St. Cloud Times via Associated Press
CAMP RIPLEY, Minn. (AP) -- Brian Dirks stands on a gravel road lined with dense forest, a radio antenna in his outstretched hand.
He punches the frequency of his target into a receiver hanging from a strap over his shoulder, aims the antenna toward an overgrown swamp and listens, ignoring the low booms of artillery fire in the distance.
For a few minutes, nothing. Then Dirks hears what he's been waiting for: a faint but distinct sound that tells him the young male gray wolf is nearby. With a couple of readings, a compass and a map, Dirks can use simple geometry to pinpoint the wolf's exact location.
A Humvee rumbles by, and Dirks steps to the side of the road to let it pass. Here, working with and around the military is a way of life.
The research began 16 years ago after gray wolves were first spotted in Camp Ripley near Little Falls, the St. Cloud Times reports (http://on.sctimes.com/NuPQn7).
The 53,000-acre military training facility is also a wildlife refuge. Although some areas are heavily used for troop training, much of its vast forests, swamps and hills have little, if any, human activity.
This is the southern edge of the range for gray wolves, which were hunted, trapped and poisoned until fewer than 700 remained in Minnesota by the 1970s. In 1974, they were federally protected as an endangered species.
Since then, wolves have made a steady comeback. Wolf tracks were first discovered at Camp Ripley in 1993, and pup sightings were reported soon after.
Federal officials wanted to know how the protected wolves were affected by military exercises, and whether training activities would need to be restricted. In 1996, the U.S. Department of Military Affairs began funding the Department of Natural Resources to capture some of the wolves, fit them with radio collars and release them so they can be monitored and tracked.
The study has provided researchers with valuable knowledge about the size of the packs, how far wolves travel and how they coexist with humans.
Since the start of the study, 41 of Camp Ripley's wolves have been captured and collared, although few are still alive. Researchers are currently monitoring four collared wolves.
In January, gray wolves near the western Great Lakes were removed from the federal endangered species list. The DNR adopted a plan to manage the wolf population in Minnesota and is working out details for a hunting season this fall that will allow 400 wolves to be harvested. Wolf hunting won't be allowed at Camp Ripley, but the animals sometimes leave the camp's borders.
The recovery of gray wolves is good news for the researchers who have spent years studying the animals' movements. They say the focus of the Camp Ripley wolf study might change, but its importance won't diminish.
"The program's really been successful," said Jay Brezinka, Camp Ripley's environmental supervisor.
They nicknamed Wolf No. 18 "Lucky," because he seemed invincible.
Captured in 2001 and fitted with a radio collar, Lucky was the alpha male of a wolf pack living on the northern end of Camp Ripley.
He survived mange, porcupine quills and injuries that caused him to lose several toes.
His luck ran out in January 2006, when he left the camp and was killed by a car on Minnesota Highway 371.
Throughout the study, there consistently have been at least two wolf packs on the camp, one in the northern part and one in the southern part near Miller Lake, said Dirks, the DNR animal survey coordinator who oversees the study.
The packs number six to eight wolves each. The pups tend to stay with the pack for one to three years, then strike out on their own, Dirks said.
The camouflaged animals can be difficult to spot from the ground, especially in Camp Ripley's dense underbrush, so researchers often use airplanes or helicopters to locate them from the air.
One of the biggest surprises has been the wolves' remarkable tolerance for humans, despite truck traffic and loud artillery fire that frequently shakes buildings miles from the camp.
"Wolves didn't care," said David Mech, senior research scientist with the U.S. Geological Survey, who helped establish the program. "It was certainly contrary to what anyone would think."
The packs often build dens within the camp's impact areas, which are closed to humans due to the risk of unexploded artillery shells.
"That showed just how tolerant wolves can be if people leave them alone," Mech said. "The point is they really don't require the wilderness that we used to think they did. They just require to be left alone."
Having wolves on camp hasn't affected military training at all, Dirks said.
"The wolves have adapted to living on the camp really well," he said. "We're lucky if we see one."
Wolf No. 16, known as "Sue," was captured and collared in 2001 when she was a year or two old.
In April 2002, she left Camp Ripley and headed northeast, following the shore of Lake Superior into Canada.
The following September, she was found shot to death in Michigan's Upper Peninsula.
What researchers have learned is that once they leave Ripley's boundaries, the wolves are much less likely to survive. Many of the monitored animals have been shot, trapped or hit by a vehicle.
Illegal shooting has been the biggest mortality factor, Dirks said. About half of the dead, collared wolves recovered by researchers had been shot.
"Truth is, when they leave camp, they're moving into a much more hostile environment," he said.
Wolves have the "problems of success," Brezinka said. Due to their recovery in areas with higher population density, there's more likely to be conflicts with humans.
"The wolf is an animal that you love or you hate," Brezinka said.
Hunting of wolves won't be allowed within the camp. But researchers realize that some of the wolves from the Ripley packs -- including those with collars -- might be shot outside the camp borders.
The DNR's plan divides the state into two management zones. In northern Minnesota, killing a wolf will be legal if it's posing an immediate threat to pets or livestock. In the rest of the state, the animal doesn't have to be posing an immediate threat.
"There will be some people who will take that fairly liberally," Dirks said.
Still, Dirks is convinced that gray wolves needed to come off the endangered species list, and he has no doubt that the population will continue to thrive.
He notes that wolves surpassed the state's population goal of 1,500-1,750, and there are now an estimated 3,000 gray wolves in Minnesota.
"That's a recovered population," Dirks said. "They're well established in the state."
Wolf No. 11, a female, left Camp Ripley alone in March 1998 and headed eastward. She wore a satellite collar that allowed researchers to track her movements beyond the camp.
To their astonishment, the wolf made it all the way to Green Bay, Wis., before eventually circling back and returning to Ripley.
Over six months, she traveled a total of 2,641 miles. It was the longest journey by a gray wolf ever documented.
The Camp Ripley program isn't the largest research study of gray wolves, or even the lengthiest. Researchers have studied the wolves on Isle Royale for more than 50 years, Mech noted.
Still, the study has provided valuable insight into how wolves live, die and can co-exist with humans, the scientists say. It's also confirmed the importance of large tracts of undeveloped land as habitat for wolves, Mech said.
"Any kind of wild areas that are large enough to sustain wolves become reservoirs for them, and it helped establish the population in the area," he said.
The study has generated publicity over the years, including a National Geographic crew that filmed footage about the wolves last year for a documentary about the Mississippi River. The researchers occasionally have allowed the media and even school groups to observe a capture, when they tranquilize the wolves to check their health or replace their collars.
Still, misconceptions about the study persist. Some people think the DNR is responsible for planting the wolves at Camp Ripley, Dirks said, rather than just monitoring them.
However, there have been very few complaints from nearby landowners about the wolves killing livestock or pets. Dirks speculates that's because with plenty of deer on the refuge, there's little need for the wolves to seek food elsewhere.
With the de-listing of wolves comes a shift in the program, but it won't be the end of the study.
The federal government wants to continue to monitor the progress of the wolves' recovery and the impact of de-listing for the next five years. Because they won't be actively hunted, the Ripley packs will serve as a sort of control group for researchers to compare to wolves in areas where hunting is allowed, Dirks said.
Having collared wolves will be of value in helping researchers understand the interaction between hunters and wolves and how easy or difficult it is to shoot one, Mech said.
After the five years is up, the focus probably will shift to studying another plant or animal -- possibly red-shouldered hawks or Blanding's turtles, Dirks said. Studies on black bears and fishers are already under way.
The researchers at Camp Ripley already are looking ahead and hoping for similar success.
"It provides us another opportunity to target another species," Brezinka said.
Information from: St. Cloud Times, http://www.sctimes.com
Copyright 2012 The Associated Press.