Wisconsin Ag Connection - Study: Wisconsin's Black Bear Population is Larger Than Thought

Wisconsin Ag News Headlines

Study: Wisconsin's Black Bear Population is Larger Than Thought
Wisconsin Ag Connection - 06/13/2008

Preliminary results of a two-year cooperative study of Wisconsin black bears suggest that the population may be twice or more larger than currently thought. But biologists stress that the new estimate comes from a half finished study and may change when data from the second year of the study are analyzed.

"This is good news," said Keith Warnke, Department of Natural Resources deer and bear ecologist. "It means we have a healthy bear population, and we may be able to expand bear hunting opportunity. The other good news is that more people will have opportunities to see these great animals in the wild."

The two-year, DNR-funded study was conducted by University of Wisconsin-Madison Wildlife Ecology graduate student Dave MacFarland under the guidance of Dr. Timothy Van Deelen.

Warnke says the preliminary results are comparable to bear densities in Minnesota and Michigan's Upper Peninsula.

In the bear study, some 3,500 baits marked with tetracycline were set out across the state's bear range in 2006. Tetracycline, when ingested, is harmless to bears but leaves a telltale line in a bear's bones. Successful bear hunters in 2006 and 2007 were asked to provide a section of a rib bone from bears they harvested for analysis. From those samples, the biologists were able to use a formula to calculate the estimated bear population.

Currently, biologists track black bear populations by placing a series of baits on routes in each county throughout the black bear's range and record which are consumed by bears over a week long observation period.

Adult black bears typically weigh 250 to 500 pounds for males and 200 to 450 pounds for females. Infant bears, called cubs, are born quite tiny but by the time they are two months old, they weigh about six pounds.