Study: Second wolf hunt reportedly drives Wisconsin wolf population to ‘abnormally low levels’

University of Wisconsin-Madison researchers say a second wolf hunt last year would have risked dropping Wisconsin’s wolf population to undesirable levels, including that the wolf could become endangered or s ‘extinguish in Wisconsin.

The study published in the scientific journal PLOS One found that it is more likely than not that well-regulated hunting would have required putting wolves on the national list of threatened and endangered species. Researchers concluded that a repeat of the February wolf hunt, in which hunters killed 218 wolves in less than three days, risked wolf extinction across the state except on tribal reservations.

A Dane County judge suspended Wisconsin’s second wolf hunt last fall, and a federal judge reinstated wolf protection in February. Even so, the study looked at several potential outcomes that could have resulted from a second season.

These results were based on quotas offered by the Natural Resources Council of the Wisconsin Department of Natural Resources and no harvest last fall. The council had approved a harvest of 300 wolves while the DNR set a quota of 130 wolves.

Adrian Treves, a professor of environmental studies at UW-Madison, said his lab found that any wolf hunts last fall risked dropping Wisconsin’s wolf population below the management goal. State of 350 wolves.

“What we’ve tried to show in this article is that if you consider the science, a quota over 16 actually creates some risk,” Treves said. “And the DNR was not transparent about this risk, if they were even aware of it.”

Treves and fellow researcher Naomi Luochouarn used two methods that MNR relied on to develop wolf population estimates and built a model to predict the outcomes of these harvest scenarios. The study’s modeling found that a harvest of between 16 and 88 wolves last fall would likely have dropped the population below 350 wolves.

Researchers also found there was a greater than 50% chance the wolf population would have fallen below the state’s endangered species listing threshold of 250 wolves if hunters had killed between 113 and 189 wolves. And the study found that no hunting posed a 13% chance that the population would fall below the state’s management goal.

Treves argued that the state should have been more cautious about a fall wolf hunt due to uncertainty with the state’s population after the February wolf hunt of last year. He said that, combined with uncertainty about the wolves’ ability to breed successfully, it was difficult to determine the effects of a second hunt on the wolf population.

Treves added that the state’s current occupancy model for assessing the wolf population has not been published or evaluated by scientists, and he argued that the agency underestimates wolf mortality.

He pointed out that the DNR estimated that 13% of wolves die from non-harvest human-caused factors as part of quota development last fall. Treves said that estimate is unscientific and appears to be based on reported wolf deaths, which excludes wolves that die and are not found. He said their study estimates that 38-56% of wolves die on average each year, and that includes wolves killed by hunters, disease and illegal killing.

“I think our goal is always to improve the science that informs the management of science-based management,” said Louchouarn, a doctoral student at the Nelson Institute for Environmental Studies at UW-Madison. “But, if management that claims to be based on science isn’t, then no matter how good our science is, it won’t really succeed in improving management.”

However, some researchers question the study’s assumptions, including Adrian Wydeven, a former state wolf biologist who now co-chairs the wildlife task force for Wisconsin’s Green Fire conservation organization.

Wydeven said the results of the study are highly unlikely. He said the study assumes an unreasonably high estimate of wolf mortality.

“At this level, the population could never have grown as much as it is now,” Wydeven said. “So it’s a really artificially high level of mortality that he’s using in his modeling.”

DNR data shows Wisconsin’s wolf population has more than quadrupled in the past two decades to around 1,100 wolves last year before the February wolf hunt. Research by Wydeven and DNR scientists found that approximately 24% of wolves die each year due to illegal killing, natural causes and human-caused mortality, such as collisions with vehicles and hunting.

Wydeven also said the study assumes that only 20% of cubs survive from summer to fall, which he says was based on a study that incorrectly reported the survival of wolf-raised cubs. wolves. He said that, combined with the study’s higher estimated death rate, this creates “an extremely low number which is not very realistic”.

He also noted that the state’s occupancy model for estimating the wolf population was published in a peer-reviewed journal last year, which shows that the DNR’s method for estimating the wolf population is valid. But Treves argued that the paper does not provide raw data to show how the model turns this into a population estimate.

Erik Olson, associate professor of natural resources at Northland College, said the study makes assumptions that could be challenged or debated. He said the researchers recognize they are introducing a bias with a higher estimate of wolf deaths that are unrelated to wolf hunting, which they believe offsets the bias that discards unreported deaths and the excessive illegal logging.

“That represents a potential range of outcomes, but it doesn’t represent the full range, or potentially even the most accurate range, of potential outcomes for these quotas,” Olson said.

Even so, Olson agreed with the study’s conclusion that the DNR needed to take precautions in setting a quota last fall.

“They were put in an awkward position to determine a quota,” he said. “The process of identifying this quota should include a wider range of potential outcomes due to the greater uncertainty we have about how the wolf population would react to a wolf hunt like the one we had in February. latest.”

The state held three wolf hunts in 2012, 2013, and 2014 when the animal was not under federal protection. Hunters harvested 117, 257 and 154 wolves in those respective seasons. Wydeven said these hunts demonstrate that some harvesting can be allowed without causing a drastic population decline, particularly if the hunts take place during the fall wolf season.

Treves countered that the comparison is not fair since the February wolf hunt took place during the wolf’s breeding season and likely led to fewer pups being born from females that were killed.

Both Wydeven and Olson say the real test will compare the study’s results to the DNR’s population estimates for last winter, which are expected to be released in the coming weeks.