Wolf study raises questions about what’s going on in Wisconsin’s woods

By: - July 12, 2021 7:00 am

Image by Christel SAGNIEZ from Pixabay

After contributing to an independent study to assess how many wolves were killed during the February wolf hunt, Professor Adrian Treves expected some criticism. “There’s just more controversy surrounding wolves, their protected status, and the conflict that some people experience with them that makes management very difficult and controversial,” Treves, a professor of environmental studies at UW-Madison’s Nelson Institute of Environmental Studies, told Wisconsin Examiner. It’s also normal for new research to be debated, questioned, and compared with other existing information. Treves, however, feels that’s not how the Department of Natural Resources (DNR) is handling the study’s findings.

Professor Adrian Treves (Photo | UW-Madison)
Professor Adrian Treves (Photo | UW-Madison)

Wisconsin’s wolf hunt of five months ago raised concerns for a number of reasons. The DNR was sued by a Kansas-based hunting organization to compel a hunt soon after the gray wolf was removed from the federal endangered species list. At the time, just over 1,000 wolves were known to live in the state, distributed among 256 packs along with 16 lone individuals. A quota for 200 wolves was quickly set by the DNR, including 81 allocated on Ojibwe tribal lands. That’s about 16% of the population, erasing a 13% increase which occurred when the wolves were federally protected.

The DNR was unable to thoroughly consult with the tribes due to the pressured timeline following the court loss. The season lasted just two days, with hunters exceeding the quota even after tribal communities opted not to hunt their portion. The hunt was also the first to occur during the animal’s breeding season, with advocates concerned that pregnant females would also be killed.

Wild Rivers Legacy Forest emerging onto a river in sunlight view
Wild Rivers Legacy Forest (Courtesy of TNC © Jeff Richter)

After the season closed early, the hunt was dubbed an unenforceable “slaughter” by conservationists and researchers. Wayne Pacelle, president of Animal Wellness Action, highlighted at the time that there were four hunters to every wolf during the season. “It’s bad enough that the kill is capped at 200, an enormous percentage of the state’s wolf population,” said Pacelle. “But that cap is unenforceable given the compressed time period for the hunt.” Pacelle warned that “many wolf packs throughout the state will be decimated, for no reason other than groundless vengeance and thrill-killing.” He asked, “Is there anything more diabolical as hunting and cruelly trapping these family-oriented animals at this scale during their breeding season, just after they were wrongly removed from the list of federally endangered animals?’’

Environmental organizations and members of the DNR’s Natural Resources Board had concerns about the quota number. Over 27,000 applications to hunt wolves were received, with just 2,380 available. In every hunting zone set by the DNR, hunters killed more wolves than allowed by the department.

The new study by Treves and scientists Francisco Santiago-Avila, and Karann Putrevu, comes as the DNR plans to hold another wolf hunt in November. Analyzing a number of factors, the study suggests that at most 695-751 wolves were alive in Wisconsin as of April. Compared to the prior year, that’s a 27-33% decline, which “contradicts the state expectation of no change in the population size,” the study finds. It highlights that, “the state wildlife agency (DNR) did not meet its explicit objective of no change in the wolf population.”

Gray wolf (photo from Pixabay)
Gray wolf (photo from Pixabay)

The study also factored in the prospect of illegal or “cryptic” poaching, which may be difficult for state agencies to detect once it has occured. “During these periods, we see an effect on poaching, both reported and cryptic,” said Santiago-Avila. “Additional deaths are caused simply by the policy signal, and the wolf hunt adds to that.”

The study also notes that hunters exceeded the quota by 83% “before the DNR could close zones.” It recommends “greater rigor and independent review of the science used by agencies to plan wolf hunting quotas and methods.” Additionally, the study calls for “clearer division of duties between state wildlife agencies, legislatures, and courts.” These measures, and more, are required to avoid an emergency re-listing of the gray wolf, the study concludes.

The study’s biggest critic: DNR

Since the study was released earlier this month, the DNR has been pushing back against its findings. Spokesperson Sarah Hoye told Wisconsin Examiner, “We at the DNR stand by our science, including our approach used to inform the February 2021 harvest decision, and remain confident in our continued ability to provide data-driven results to inform policy decisions involving wolves.” Hoye called Treves’ population comparisons an “inappropriate, apples to oranges comparison.”

“Wolf populations naturally fluctuate over a year,” she said, “and the appropriate comparison of population sizes to assess impact of harvest to the population requires a one-year time step comparing similar points in the population cycle. In other words, the authors would need to compare pre-hunt 2021 to pre-hunt 2022, Or April 2021 to April 2020, for which data are not yet available.” She accused the researchers of relying on “methods that have been repeatedly criticized in the scientific literature.” For example, she said, the researchers assumed that animals whose tracking collars failed were illegally killed, which she calls “speculative.”  Using data from a 2008 paper, Hoye stated that Wisconsin could expect an increase in the wolf population, not a decline.

A gray wolf (Getty Images). Endangered species hunting DNR
A gray wolf (Getty Images).

Treves says the DNR has simply not provided enough data. He says his study’s Even estimates of wolf killings, while  high, are still the most conservative numbers they could calculate. Unpublished and unverified DNR estimates that 17 of the department’s 50 radio-collared wolves disappeared during or before 2021, and another seven were killed by hunters, were not included in the study. “Had we uncritically used those figures for deaths and disappearances of the entire wolf population,” the study noted, “our estimate of wolf mortality would have been 48% and the associated wolf population decline would have been much greater.”


The DNR also did not collect wolf carcasses to examine aging, or evidence of breeding among alpha females, researchers say. Without that information, the study noted that “illegal wolf-killing is more difficult to detect, the age and reproductive class of hunter-killed wolves is likely imprecise, and the breeding status and hence reproductive performance for the following year cannot be estimated accurately.” Because these examinations weren’t conducted, the researchers were unable to project beyond April 2021. Other information could not be assessed due to what Treves calls a systematic lack of transparency.

Treves welcomes healthy debate, he says, which is part of the process for public policy making and scientific study. However, in this case, he feels the DNR is dismissing research findings “without presenting evidence to the public.”

The environmental professor adds that his research team has sent the DNR its own independent data since 2012, “suggesting to them that they’re underestimating mortality, showing them why they’re underestimating morality,” Treves told Wisconsin Examiner, “and arguing that they’re setting too high a quota. And yet, the DNR is withholding data from us, without explanation.” Coupled with other factors like difficulty locating archived wolf data, that lack of communication suggests to Treves that “we’ve got more than a scientific debate going on here. There’s a serious lack of transparency.”

Photo by christels on Pixnio
Photo by christels on Pixnio

Lack of transparency makes it much more difficult for researchers like Treves to conduct independent studies. “I would say that the DNR does its own research, and prefers its own research,” said Treves. “Even when its own research is questioned on scientific grounds it often doesn’t correct errors or reverse course to try alternative methods.”

Hoye pointed to the DNR’s use of an occupancy-based estimate model to help inform hunting quotas as among the best available science. Adding that the model is peer-reviewed by the Journal of Wildlife Management, Hoye noted that Treves’ study relied on a different counting method and did not use  the model used to inform the wolf quota. She added that, “during quota discussions, the DNR used a non-harvest, human-caused mortality of 14% to determine a quota. The known mortality rate was [less than] 5%, resulting in a conservative mortality rate.”

Treves, however, isn’t convinced by the occupancy model used by DNR, which over the last four years has predicted higher population numbers than its predecessors. “And we don’t yet have a good explanation of why it always predicts a higher number of wolves than the older models,” said Treves.

A picture showing how Wisconsin was broken up into 6 zones for the wolf hunt. (Picture from Department of Natural Resources)
A picture showing how Wisconsin was broken up into 6 zones for the wolf hunt. (Picture from Department of Natural Resources)

Despite the confusing dueling  numbers, terminology, and scientific jargon, Treves feels the big picture is clear. “Population models can be pretty simple and transparent,” he said, “and don’t need to be shrouded in a lot of complicated science to be understood by the average, fairly literate person.” He emphasized that, “the policy decisions should be made on the latest available science published, like we did, in world-wide, top, peer-reviewed scientific journals. That should be the basis for public policy. Not anecdotes and observations, unpublished analysis or data published in weak journals that hasn’t withstood the kind of scientific debate that we’re talking about.” Treves’ study was published in the Journal of Life and Environmental Sciences of PeerJ, a peer-reviewed open access journal publishing primary research and reviews in biology, life sciences, environmental sciences, and medicine.   

Ultimately, Treves hopes the study will help convey a difficult truth about the wolf hunts. “Ethical hunters should recognize February was a violation of the public trust doctrine and fair chase principles,” he says.

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Isiah Holmes
Isiah Holmes

Isiah Holmes is a journalist and videographer, and a lifelong resident of Milwaukee, Wisconsin. Holmes' video work dates back to his high school days at Wauwatosa East High, when he made a documentary about the local police department. Since then, his writing has been featured in Urban Milwaukee, Isthmus, Milwaukee Stories, Milwaukee Neighborhood News Services, Pontiac Tribune, the Progressive Magazine, Al Jazeera, and other outlets. He was also featured in the 2018 documentary The Chase Key, and was the recipient of the Sierra Club Great Waters Group 2021 Environmental Hero of the Year award. The Wisconsin Freedom of Information Council also awarded Holmes its 2021-2022 Media Openness Award for using the open records laws for investigative journalism. Holmes was also a finalist in the 2021 Milwaukee Press Club Excellence in Journalism Awards alongside the rest of the Wisconsin Examiner's staff. The Silver, or second place, award for Best Online Coverage of News was awarded to Holmes and his colleague Henry Redman for an investigative series into how police responded to the civil unrest and protests in Kenosha during 2020. Holmes was also awarded the Press Club's Silver (second-place) award for Public Service Journalism for articles focusing on police surveillance in Wisconsin.