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Email: timberwolfinfonetwork@gmail.com
Email: timberwolfinfonetwork@gmail.com

WI: UW professor studies wolf mortality

Two years after Wisconsin’s first recreational wolf hunting season began, controversy over the subsequent mortality rates has led to independent population studies from researchers at University of Wisconsin.

The Wisconsin Department of Natural Resources and the Fish and Wildlife Service require that any wildlife removed from the protection of the “endangered” label be monitored for the following five years. Recent debate centers around whether or not the monitoring has been up to standards, specifically if mortality in the wolf population in the state has been calculated accurately.

In August several scientists, including UW professor of environmental sciences Adrian Treves, who specializes in balancing human needs and carnivore conservation, wrote and signed a letter to the Fish and Wildlife Service.

The letter brought up that although the collaring method that the WDNR has been using has merit, there may be problems with their system. According to both the letter and WDNR officials, the WDNR uses tracking collars on a percentage of the wolf population in order to track the mortality rate among that population before applying that information to the population as a whole. The WDNR estimate came to a total of 267 dead wolves.

The letter alleges that the WDNR’s calculations omitted information on collars that had gone missing.

“When marked animals disappear, omitting them from analyses is a known biasing factor in wildlife research,” Treves said in the letter. “That omission leads to underestimation of mortality rate, if even a single mortality followed a disappearance.”

Additionally, in the mortality estimations, the WDNR included wolves that had been collected but not necessarily collared previously.

The letter says that non-radioed wolves provide imprecise and inaccurate estimates of mortality rate, either because people must encounter and report their carcasses by chance, or they are the perpetrators themselves and choose to report the mortality. Therefore, mortality estimates that include non-radioed wolves inevitably underestimate the total mortality by the number of undiscovered carcasses, the letter said.

In the letter, Treves recommends remedies to the population tracking methods for the WDNR to pursue. He recommends that the Fish and Wildlife Society revise the population monitoring results, using updated scientific methods.

Additionally, he recommended that an independent panel of scientific peer-reviewers be appointed to advise the Fish and Wildlife Society on potential action.

The WDNR, however, maintains that their mortality analysis, done in collaboration with the dissertation of UW PhD candidate Jennifer Stenglein, are correct.

“There’s a possibility, but it’s probably not biased over the 30 years of monitoring we’ve done,” Jane Wiedenhoeft, WDNR official, said. “Quotas set for 2013 intended to decrease population so we were not surprised to see the population decreased. We were surprised to see it decreased as much as it has, but it was still in the range of prediction.”

Wiedenhoeft said she does not believe that the wolf population is in danger and is fairly confident due to the close monitoring the WDNR has been performing on the wolf population.

While Wiedenhoeft said the WDNR maintains that the wolf population does not need more protection, the organization is remaining open to collaboration with UW scientists now and in the future.

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