More than 3,000 bait boxes have been set up around the state to help track the number of black bear.
The Wisconsin Bear Hunters Association and volunteers are counting bears in 35 counties.
Inside the bait boxes are antibiotics stuffed in a salty ball of bacon. The antibiotics leave a long-lasting chemical marker in the bears' bones.
When hunters kill the bears this fall, they'll submit a rib sample to the Department of Natural Resources. That will be analyzed for the antibiotic.
The University of Wisconsin will take the data and calculate the number of black bear, based on where the baits were placed, how many bear hit on the bait and how many samples contained the antibiotic.
Researchers want to track the number of bear to make sure the population doesn't get too big or too small.