Sustainability Environment

Gray wolf population declines without protections

gray grey wolf wolves wisconsin study population hunting study loss one third 33 percent maximum madison academic
In this photograph taken June 17, 2021, shows a grey wolf in its enclosure at The Zagreb Zoo.  DENIS LOVROVIC / AFP

Story at a glance

  • The gray wolf population in Wisconsin declined by up to one third of its previous population.
  • This follows the lifting of federal protections for the species under the Trump administration.
  • A hunt is scheduled for the fall of 2021 to continue to control the population.

The U.S. gray wolf population has dwindled substantially following the loss of federal and state protections, with a new study estimating a decline of 27 percent to 33 percent in the year leading up to April 2021.

The study, conducted by the Nelson Institute for Environmental Studies at the University of Wisconsin, Madison, looked at the effects of recent hunting deregulation on the local gray wolf population. 

Federal protections for gray wolves were removed in November 2020 under the Trump administration, when officials at the Department of the Interior stripped protections for gray wolves previously granted within the Endangered Species Act. This decision came as the gray wolf population in native states began to recover after decades of overhunting without regulation.

The state’s corresponding ruling surrounding lifting protections for gray wolves was “to allow for a sustainable harvest that neither increases nor decreases the state’s wolf population,” according to the Wisconsin Department of Natural Resources (DNR). Using estimates of wolves killed by hunters from April 2017 to 2020, researchers expect an additional 98 to 105 wolves have died since November 2020 due to the removal of protections. 

The authors say that cryptic poaching — or illegal killing —likely contributed to this figure.

“This contradicts the state expectation of no change in the population size,” the authors conclude. “We recommend federal governments reconsider the practice of sudden deregulation of wolf management and instead recommend they consider protecting predators as non-game or transition more slowly to subnational authority, to avoid the need for emergency relisting.”

Now, the estimated state population is somewhere between 695 and 751 wolves, a notable drop from the estimated 1,034 documented in spring 2020.

“Although the DNR is aiming for a stable population, we estimate the population actually dropped significantly,” said author Adrian Treves, a professor in the Nelson Institute for Environmental Studies and director of the Carnivore Coexistence Lab at UW–Madison, in a release.

Proponents of wolf-killing argue that the current population of wolves in Wisconsin is too high, which the report refutes as a conclusion based on flawed evidence. The authors of the study say that predator population is critical to the overall health of an ecosystem, and, if the forthcoming fall 2021 hunt is canceled, the wolf population stands to rebound within one to two years. 

The Wisconsin DNR states that it is planning for a scheduled hunting harvest of wolves in the fall of 2021 as part of a larger 10-year management plan.