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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

Maggie Heino cradles a cub. Heino has tracked bears in fall and winter for 20 years. © James C. Bishop, Jr.

December 2004

Where sleeping bears lie

For 20 years, Maggie Heino has tracked the roving black bear population across northern Wisconsin.

James C. Bishop, Jr.


Maggie Heino cradles a cub. Heino's research covers bear habitat use, population growth, survival rates and more.

© James C. Bishop, Jr.
The annual fall and winter routine | Moving on
Tools and timing of the bear research trade

At the base of a snow-covered hill a few miles west of the village of Clam Lake, a group of bear researchers waited for a tranquilizer drug to take effect. A few minutes earlier they had injected a sow bear with just enough drugs to put her to sleep. The team of an Ashland schoolteacher, a DNR wildlife specialist, two University of Wisconsin- Stevens Point students and Margaret "Maggie" Heino, quietly stood by.

Fifteen minutes later the snoozing sow and her two cubs were removed from their hillside den, weighed, measured, given health checks and tucked back into their winter home. The animals were in good hands.

The team leader, Maggie Heino of Sanborn, has been researching bears since 1985 as a volunteer. Following the passing of researcher and mentor Professor Ray Anderson of UW-Stevens Point in 2000, Heino was named Field Coordinator for black bear research throughout northern Wisconsin. Her willingness to work helped ensure that Anderson's many projects would continue.

"At the time, DNR's Big Game Specialist and the Wildlife Bureau Director (Tom Hauge) supported the decision for me to lead the winter research," Heino said. "They knew that I had the equipment, the frequencies for the radio-tagged bears and I knew the resource."

DNR Wildlife Specialist Bruce Kohn, who has since retired, served as the interim bear project scientist working with Heino and Tim Ginnett, an incoming Associate Professor of Wildlife. They decided to take on a big task – removing collars from the Stockton Island bears in the winter of 2001 and replacing collars on the mainland bears under study.

The college's Associate Dean of Academic Affairs, Professor Christine Thomas, met with state agencies to discuss removing radio-collars from bears on Stockton Island and removing or re-collaring denned bears on the mainland that were tracked in long-term research.

She was also dedicated to continuing this invaluable work. Heino has handled bears in more than 500 den sites in Wisconsin. The collective research has examined the role bears play on our landscape including habitat use, population growth, survival rates, effects from translocating bears and the effects of activities like hunting bears with hounds. Such research is valuable in determining how to sustain bear populations while reducing conflicts in areas where they live close to people. Regulated bear harvests have increased the state bear population mainly in northern Wisconsin even as more people move into rural areas.

Nuisance encounters, like bears tearing down bird feeders, getting into garbage cans and breaking into cabins for food, have been on the rise too. Heino's research data along with other surveys, are used by wildlife managers to determine harvest quotas and maintain a healthy bear population. Heino along with state and federal agencies continue to educate people on how to reduce conflicts with bears around homes and cabins.

At this particular bear den, where you can hear the roar of vehicles from Highway 77 only a short distance away, Heino is concerned about a particular sow. In a check last year this sow was missing a front leg and infection had set in. The injury could have been from a bullet or a vehicle collision.

For this year's checkup, Heino brought along a veterinarian, who gave the animal an injection of antibiotics.

"Last year the sow weighed 115 pounds, down from 165 pounds when we checked her in 2002. We were all delighted to find her today at 235 pounds with two healthy cubs," Heino happily reported.

This research and similar projects on the Hanson Forest near Mellen and in the Ashland area are supported by a host of donors and volunteers including the UW-Stevens Point, the Wisconsin Bear Hunters Association, Safari Club International, the Rocky Mountain Elk Foundation, the Paul Family Foundation, the Whiskey Jack Camp, Ashland High School, the Department of Natural Resources and some anonymous donors.

Heino is reimbursed by the university for her expenses and receives a small honorarium. She owns a bit of the research equipment, but the bulk of it belongs either to the DNR team or the university.

The annual fall and winter routine

On any particular winter hike into a den site, the bear researchers may invite a small group of observers to tag along. These might include school groups, members of the nearby Whiskey Jack Camp or the media. The team moves in on snowshoes and prior to heading out, Heino briefs the visitors.

She explains that bears are only handled or processed during the denning season or as newly captured animals. The scheduled visits begin in October when bears start getting drowsy and look for a place to hibernate.

Heino monitors radio-tagged bears during the hunting season in September to determine which ones survived, where they are located and whether they left their home ranges. After reviewing hunting harvest reports, she locates remaining bears then tunes in their radio collar frequencies again after the November gun deer season to determine if bears have settled into their winter dens. Once Heino locates a bear in the same spot three times during her travels, she considers it "denned up" for the season.

After Christmas, she walks into the sites and marks them. Dens with sows that are expecting to have cubs are visited last. Heino listens closely for whimpering cries and other vocal clues.

Once all the dens are checked, she sets up a handling schedule based on the numbers of dens, locations, and den type (single bear, sows with yearlings, or sows with cubs). Heino will come back later in the winter to ensure the transmitters are functioning properly and the bears are still at their den sites.

Moving on

The bears leave their dens in spring, usually after a heavy rain or thaw. They will be on the move until mid-October, and Heino's crews periodically tune-in to follow their ramblings.

Sows are a bit easier to track. Research shows their home ranges average about eight square miles. Boars move in a wider swath covering about 61 square miles on average.

The females leave a scent trail that the males can follow. As three-year-olds, both males and females sexually mature and mating takes place in June and early July.

At about four years of age, sows produce their first litter of cubs in late December and January. Cubs den with their mothers until they are yearlings in the following spring, when Heino says the sows "kick them out." Yearlings can stay in the same vicinity and share the same home range, but the sow won't allow them to stay with her. This cycle continues and sows go into estrus, breed and produce cubs every other year.

Tools and timing of the bear research trade

A sample of yearlings and sows get radio collars when they are captured or found in their dens. During spring and summer, some bears are captured in barrel traps or snares for research or are removed if they become a nuisance to people.

Collars are sized to the animal and equipped with leather spacers designed to break away after 18 months. This prevents injury when researchers are not able to recapture the bear before it outgrows the collar.

Each collar transmits a unique frequency so individual animals can be followed with either a hand-held antenna or a larger antenna mounted to a vehicle. Depending on the terrain, bears can be detected up to a mile away with hand-held devices and longer distances with a vehicle-mounted antenna on flatter terrain.

A bear emerges from its winter den. Medical researchers study how bears' kidneys process waste during hibernation for clues in treating human kidney disease and preparing astronauts for long-term space travel. © Gerard Fuehrer
A bear emerges from its winter den. Medical researchers study how bears' kidneys process waste during hibernation for clues in treating human kidney disease and preparing astronauts for long-term space travel.

© Gerard Fuehrer

The animals will be followed by radio until they are harvested, their collars fall off, the units quit transmitting, or the bears die of natural causes.

In a typical year up to a dozen active dens are found and revisited as part of the research project. For example, in 2000, thirteen dens were visited in three weekends. A total of 39 bears were processed including 10 adult sows, three sub-adult females, 17 yearlings and nine cubs. Depending on the project Heino's workload can get even busier.

During a population dynamics study from 1984 to 1994 up to 50 dens were visited. "That was every weekend and sometimes three-day weekends processing three dens per day," she recalled. "It was exhausting." A total of 133 bears were captured, collared and followed year-round.

The dens, like the one outside of Clam Lake, may consist of dug holes or be nothing more than a pile of brush. Research shows that 34 percent of the dens were total excavations, 26 percent were brush piles, 17 percent were partial excavations, nine percent were rock caves, and four percent were hollow trees as well as other types. Only about four percent of the dens are reused and rarely by the same bear.

Boars and sows do not den together although Heino observed there have been instances where boars denned in the same area as sows that produced cubs that year.

Most dens are located away from human habitation making travel into them a "healthy walk," especially with equipment, so having a few other "assistants" can be handy.

Once visiting observers are briefed, Heino and the core team share the load of hauling two weighing poles, antennas, saws, and bags of gear to the observers. Most enjoy taking something in as part of the team.

The weighing poles are about five feet long and made of aluminum. When the poles are assembled, four people can lift a bear in a net off the ground. A scale suspended between the poles provides an accurate reading of the animal's weight.

Before the entourage gets within 150 feet or so of the bear, the researchers leave the observers behind and approach the den quietly. Bears are not true hibernators and have been known to flee.

"On one occasion, after a 20-minute snowmobile ride, we hiked in on a boar for 1 hours on snowshoes in the Bibon Swamp near Mason," Heino recalls, "only to have him get up and walk away. He was in a nest bowl on top of the ground. Two weeks later with the temperature well below zero, we made another attempt. He had moved a quarter mile away and again when we were within 50 yards of him, he got up and left. We were unable to change his collar that year. The next year, he was in a normal den – a dugout under an old snag and we processed this 400-pound male without any problems. It's pretty disappointing when they flee, especially when you're carrying all that gear."

Fortunately the three-legged sow near Clam Lake stayed put. Bruce Prentice, a high school biology teacher from Ashland, took aim with a flashlight in one hand and dart gun in the other, found a fleshy spot on the animal, and shot.

When the sow was safely sedated the observers were called in. Prentice and the students gently withdrew the cubs and handed them to waiting arms. The lumps of black screaming fur were kept warm inside coats until Heino placed them into a wool hat to be weighed. They were also sexed and a hair measurement taken.

Cubs weigh about eight ounces when born. These two weighed between four and five pounds. Yearlings can weigh up to 40 pounds and must be sedated like their mothers.

"Handling cubs in the winter dens has no effect on their fear of humans in subsequent meetings," Heino said.

Whether working on small or large bears, following routines keeps the job pretty safe. In all her years as a researcher Heino had only one incident where a large bear scratched a researcher. "The incident was pretty minor and no one was hurt," she said. At most, small cubs scratch a bit or may nip a chin.

Observers get a choice of assisting or simply watching the researchers work. Visitors may help weigh the bear or observe as researchers take a stethoscope and monitor the sow's heart rate, respiration rate or take the bear's temperature. Like a thorough tailor, a team member uses a flexible tape to measure and record each bear's chest and neck girth, total length and footpad size.

Ear tags and lip tattoos serve as permanent identification numbers. Once collars drop or if ear tags fall off, a bear that's recaptured or killed during a hunting season can be identified with the lip tattoo.

"In 1989 we trapped and collared a 400-pound boar," Heino said. "During den processing in 1991, it weighed over 500 pounds. We lost track of it when its collar fell off in the Bibon Marsh during the winter of 1992. Then on September 24, 1998 a hunter harvested the bear and it weighed 678 pounds! It was the largest bear we ever processed and we determined it was 24 years old."

Over the years, she has followed generations of bears as the sows and yearlings are collared and marked. "We captured sow number 105 many years ago, her granddaughter number 241, and great-granddaughter sow number 75. They all are still on the air," Heino said. Bears can live to be 35 years old.

When the bear management program started in 1985, the state's bear population was estimated at about 4,750 animals. Their range and population have been rising steadily and now number between 11,150 and 14,000 bears.

Keith Warnke, DNR big game ecologist, said that prior to 1985 anyone could harvest a bear with a big game license. That year the Legislature let the department set seasons, sell special bear hunting licenses and regulate harvests.

By 2004, nearly 4,700 permits were sold with the goal of harvesting 2,500 bears. Over 56,000 hunters applied for harvest permits using a cumulative preference system. This is a far cry from a time when Heino was growing up on a farm south of Ashland.

"Even though we had fewer bears back then, farmers shot nuisance bears nearly at will," she said. "It was one of the reasons for the declining populations that led to more protective management."

Today she lives outside of Sanborn with her husband Jerry, a few miles from where she spent her youth. Last April she retired from the U.S. Park Service where she worked full-time as a budget technician and volunteer coordinator.

During her 20 years as a wildlife research volunteer, Maggie Heino has worked on state and federal studies of white-tailed deer, bald eagles, elk, woodcock, ruffed grouse, gulls, cormorants, and amphibians.

"In Bayfield, they called me the 'Frog Lady,'" she said, referring to an independent three-year study she did on frogs and toads of the Apostle Islands National Lakeshore. Her data provided the baseline information on eight frog species and Wisconsin's one toad species. She wrote the monitoring plan, conducted surveys and submitted the final results in a report to the National Park Service.

But it is bear research that Heino still finds most fascinating. She enjoys knowing that the background information the collared bears signal can be used to benefit the animal.

"At den sites like this or following bear around a forest, basic biology leaves the textbooks and becomes a real experience," she said. "I'll keep doing it as long as I'm needed, I'm healthy, and there is work to be done."

The three-legged sow soon begins to come out of her drugged state. Researchers quickly finish their work. Before sliding her into the hole, they dab a little Vaseline on her nose, covering any remaining human scent from the recent handling because the tranquilizing drug affects her short-term memory. The sow will remember nothing of the experience as she is tucked into the den next to her cubs.

Branches, pine boughs and grass are placed over the entrance to hide it and keep out light. After the next snow, few people passing by will know that a sleeping bear and her two kids are awaiting spring's arrival.

But Maggie Heino would know. A little beep from a radio signal will help the researcher keep an eye on this speeping crew.

James C. Bishop, Jr. is Public Affairs Manager for DNR's Northern Region in Spooner.