By: Sam Cook, Duluth News Tribune
Wisconsin’s method of estimating its wolf population is similar to Minnesota’s. The Wisconsin Department of Natural Resources uses a combination of aerial surveys and ground sightings of wolves and wolf tracks to estimate the population.
As of winter 2012, the state had an estimated wolf population of 815 to 880, said Adrian Wydeven, mammalian ecologist for the DNR.
The state has nearly 40 wolves radio-collared. DNR officials make weekly flights throughout the year to locate these wolves by radio-telemetry. During the winter, when snow is on the ground, observers watch to see how many other wolves are with the radio-collared wolves.
In addition, DNR employees on the ground in winter keep track of wolf sightings and wolf tracks in assigned blocks of land. The DNR also relies on reports from the public and from about 140 trained volunteers who monitor wolf and wolf track sightings, Wydeven said.
The state’s estimated wolf population is a mid-winter estimate, before wolves have pups in March and April.
“This is the population at the bottom end of the annual cycle, when the population is at its lowest,” Wydeven said. “It probably doubles in the spring when pups are born. Then it levels off during the summer when they lose pups. We estimate we may lose 70 percent of the pups and 25 percent of the animals 1 year old or older.”
Wydeven said some Wisconsin residents think the DNR’s wolf population estimate is too low, but he disagrees.
“I think it’s pretty representative of the population,” he said.
The state identified 213 wolf packs in last winter’s population, with an average pack size of four. A breeding male and female wolf traveling together is considered a pack. Pack sizes range from pairs up to as many as 11 or 12, Wydeven said.