Updated bobcat population model allows for more tags in Wisconsin
Minocqua, Wis. — Bobcats are doing quite well in the Badger State and increased carcass tags for this season stand as proof.
Shawn Rossler, furbearer specialist with the Wisconsin DNR, and Nathan Roberts, DNR furbearer research scientist, told the Natural Resources Board that bobcats are a success story in Wisconsin.
“The state of bobcats in our state is excellent,” Roberts said.
Bobcats are found throughout the state and are a prized trophy animal for hunters and trappers. The DNR now estimates there are about 3,500 bobcats north of Hwy. 64, but does not yet have a population estimate for the southern part of the state.
From 1867 to 1964 bounties were paid to people who shot bobcats, and up until 1970 there were no regulations on bobcat harvest.
Roberts said that the idea to manage them as a sustainable game species is relatively new.
From 1970 to 2013 a regulated harvest on bobcats took place in the northern half of the state. Beginning in 2014, the first regulated season began in southern Wisconsin.
Ten years ago, Roberts conducted a population assessment of bobcats in the U.S. and found the population had increased from one million in 1981 to 3.5 million in 2008.
The species is now found in all states. The population is stable or expanding in states all except Florida.
“Bobcats are challenging to monitor,” Roberts said. “They are elusive and hard to see so people think they aren’t common because they don’t see them, but they are common in Wisconsin and they are doing well.”
The DNR monitors bobcats by obtaining information from carcasses harvested by hunters and trappers. The DNR also uses tracking collars in two study areas, putting collars on 61 cats during the past three years.
As might be expected, since bobcats range from coast to coast and from Quebec down to Mexico, the habitat they use in Wisconsin is varied. They have relatively small home ranges, and females have very high survivorship rates.
The harvest rate is lower than what DNR researchers expected, leading them to believe the population is larger than previously estimated.
Roberts said that all of the information on population size and survivorship leads him to believe that the DNR can provide more harvest opportunities while ensuring the long-term stability of the population.
Rossler said the management program includes working with the Furbearer Advisory Committee comprised of the Great Lakes Indian Fish and Wildlife Commission, U.S. Forest Service, USDA Wildlife Services, Conservation Congress, Wisconsin Trappers Association, Wisconsin Bear Hunters Association, and Wisconsin Wildlife Federation, and the Hunters Rights Coalition.
Although committee members have many different opinions, this year the committee agreed to increase the bobcat quota for 2017 based on new – and higher – population estimates.
The 2017-18 bobcat harvest quota is 550 in the northern zone (north of Hwy. 64). This includes a state quota of 506 bobcats and a tribal allocation of five.
The DNR will issue 505 permits for Period 1 and 325 permits for Period 2.
The southern bobcat zone has a harvest quota of 200, including a state quota of 195 and tribal allocation of five. A total of 230 permits will be issued for Period 1 and 170 permits for Period 2.
Quotas are substantially increased over previous years, when quotas were 225 in 2016, 300 in 2015, and 240 in 2014.
Rossler said that 7,027 permit applications were received for the 2017-18 season .
“We want to be sure we can provide maximum opportunity whenever we can be confident that harvest opportunities are sustainable,” Rossler said.
Dr. Fred Prehn, board member from Wausau, noted that today some hunters have to wait 10 years to receive a harvest permit and some old-timers claim there used to be more bobcats many years ago.
Gary Zimmer, board member from Rhinelander, said this year’s quota was a big jump and he wondered if the state was too conservative in past years.
Roberts responded that they now have a better idea of the population, but he wasn’t willing to say the quota was too conservative in the past.
Greg Kazmierski, board member from Pewaukee, had requested the report on bobcats, saying that previously the board had never approved bobcat quotas.
According to Kazmierski, the DNR has been accused of not basing decisions on science. He said bobcat management is “great science.”
Roberts explained the reason for the increased quotas – that researchers looked at the models closely and noticed what appeared to be lower than normal reproductive rates for female bobcats in Wisconsin.
Roberts found the methodology used in past years was not appropriate to use with bobcats, and he worked with veterinarians to adjust the model.
Roberts said that the model incorporates several sources of mortality, including natural, legal harvest, illegal take, and incidental mortality.
The model used previously counted incidentally tagged bobcats, such as those killed by cars, as incidentally harvested.
“We found all of those road-killed animals were showing up in the wrong category, and adjusted for that which decreased our mortality rates,” Roberts said.
In response to a question from Preston Cole, board member from Milwaukee, DNR deputy secretary Kurt Thiede said that taking researchers out of the research bureau and re-aligning them with fish, wildlife, and forestry managers has strengthened the functions.