Waking a sleeping giant
Bear den checked as part of predator-prey study
KENTON — There better be a good reason to tranquilize a dormant black bear — which had three cubs — and drag it out of its den into the snow on a frigid winter morning.
Wildlife research would be a good reason.
The Michigan Department of Natural Resources and Mississippi State University are cooperating in a predator-prey study to estimate the survival and cause-specific mortality of white-tailed deer fawns and does. That study involves estimating the proportion of fawn mortality attributable to certain predators.
A Wednesday visit to a bear den located in Houghton County near Kenton in the Ottawa National Forest was part of that goal, even though there wasn’t a fawn in sight.
Jerry Belant, a professor of wildlife ecology at MSU, helped with Wednesday’s den visit.
“What we’re doing is looking at the role of winter weather, aspects of habitat and predation on white-tailed deer populations,” Belant said. “One of the potential predators of white-tailed deer, particularly young fawns, is the American black bear.”
Wednesday’s effort involved going into dens.
“Part of what we do is maintain a sample of each population of carnivore in the area,” Belant said, with those carnivores being black bears, coyotes, bobcats and wolves. “Doing the den inspections like we do every year is a means of them checking on the status of the animal, replacing the collars with a Global Positioning System collar so that when these bears exit in the spring we are monitoring their movements.”
That will give researchers marked samples for when fawns are born.
Belant said the 11-year study is being performed in three phases, which represent low-, medium- and high-snowfall zones in the Upper Peninsula.
The study is in the second year of the third phase.
The Wednesday visit was in the high-snowfall zone in Houghton, Baraga and Ontonagon counties.
Different amounts of snow, Belant said, can have a marked influence on deer populations as well as potential deer predators.
“The relationships between winter weather habitat and predation in relation to white-tailed deer is actually quite complicated, and we need to cover the range of conditions that we see here in the U.P. to better understand what mechanisms are driving white-tailed deer populations,” Belant said.
The DNR and MSU provided some background on the predator-prey study.
Many factors, including disease, predation, weather and hunter harvest, influence deer survival, which in the U.P. is especially influenced by winter food supply and cover.
Deer seek out landscapes with a high proportion of confier trees like cedar and hemlock to find shelter from snow and wind, and the availability of these habitats affect over-winter survival in the U.P.
Although some predators like coyotes can take deer of any age, black bears, for example, can catch fawns only during the first couple weeks of life. When deer are hampered by snow and in poorer physical condition in the winter, predators can prey upon them more easily.
So, the goal of the study is to better understand deer survival and the factors that influence it throughout the year to properly manage the deer herd.
Other objectives include estimating the home range of white-tailed deer, determining if familiarity of an area to each predator species affects the likelihood of fawn predation, and describing the association between fawn birth site habitat characteristics and black bear, coyote, bobcat or wolf habitat use.
Belant said the study is funded primarily through the Federal Wildlife Aid in Restoration Act, the Safari Club International Foundation and the Michigan Involvement Committee of SCI.
Joe Goergen, the foundation’s acting director, said it has been involved with the project since its beginning.
He had perhaps what could be considered the most enviable job Wednesday, keeping the tiny — and sometimes noisy — cubs warm underneath his coat.
“Today was the first bear den check for me, and it was obviously an awesome experience for me, having those cubs put in my chest,” Goergen said.
He said that one of the results from the predator-prey study was the creation of the Upper Peninsula Habitat Workgroup, which is working to improve winter deer habitat through deer yards across the U.P.
Also taking part in Wednesday’s bear den study was Nick Fowler, a Ph.D. candidate at MSU.
“Our primary goal is here to keep a collared sample of bears going into summer so we can use those bears to investigate their own predation on white-tailed fawns,” Fowler said. “While we’re there, it’s a really good opportunity to collect a variety of data on the bear, ranging from condition, biological samples in the form of blood and hair — more for metric data — and really just get a feel for how the bear has been responding.”
For example, weight gain can be determined, he said. This particular bear weighed 115 pounds last summer, but weighed 160 pounds on Wednesday.
That female had been caught June 29, he said.
“We tracked her movements throughout the entire time she was collared, going to any spot where she spent a significant amount of time, and that’s why we’re looking at the predation on the white-tailed deer, trying to figure out what carnivores are doing out there,” said Fowler, who noted the bear lived in the woods where the den was located the entire summer.
The bear “denned up” in October or November, and was located around Christmas, he said.
Not only did the bear gain a significant amount of weight since last summer, she produced three cubs.
However, before data was collected during the “carnivore catch,” the bear had to be tranquilized and the proper wait time followed before getting into the den, which, Fowler pointed out, was an interesting experience, even though data collection was the first priority.
“It’s just neat to see those cubs in there, and imagine that, you know, this is happening all over the place, all over the U.P.,” Fowler said.
Christie Bleck can be reached at 906-228-2500, ext. 250. Her email address is email@example.com.