The idea that state-sanctioned killing of wolves is necessary to control wolf populations is one of the most widespread assumptions in large carnivore management. However, research demonstrates that wolves limit their own numbers.

As apex predators wolves keep their own numbers in check.

Self-regulation in large carnivores like wolves ensures that the largest and the fiercest do not overexploit their resources.

According to a recent work published in OIKOS, population control is what distinguishes wolves and other “apex predators” from the rest. Wolves are highly social animals that live in well-organized family units called packs. Cooperative living gives wolf families a number of benefits. In addition to facilitating successful hunting, pup-rearing, and defending pack territory, cooperative living allows wolves to limit their own population – for example, they control the numbers within their group by only letting certain members breed. By self-regulating— they also help to keep their ecosystems in balance.

Wolf populations stabilize when carrying capacity is reached.

Since wolf reintroduction in Yellowstone over 20 years ago, the 2+ million-acre park has acted as a laboratory, offering scientists a deeper understanding of the complexity of that ecosystem, including the diverse pressures (beyond lethal control by humans) that manage wolf populations.

Because hunting wolves is not permitted within the Park boundaries, Yellowstone offers us a chance to see what happens to wolf populations when left undisturbed by humans.

National Park Service

In Yellowstone, wolf numbers have grown and generally stabilized. For the last decade, the wolf population has hovered around 100, which experts consider Yellowstone’s carrying capacity. Carrying capacity describes the maximum number of individuals or species that a specific environment’s resources can sustain for an indefinite period without degrading it. Once a species reaches its carrying capacity, population numbers stabilize.

Factors that affect the carrying capacity include:

• Food Availability
• Disease (canine distemper virus, mange, etc…)
• Intra- pack strife
• Competition with other predators (bears, mountain lions, coyotes)

Protected Wolf Populations Stabilizing Beyond Yellowstone

New data from the Wisconsin Department of Natural Resources suggests Wisconsin’s wolf population may be stabilizing too. After decades of growth, wolf numbers in Wisconsin were reportedly down by 2 percent last winter.

Wolves in Wisconsin are currently afforded protection under the Endangered Species Act, but this has not always been the case.

Federal ESA protections for Wisconsin’s wolves were removed by the U.S. Fish and Wildlife Service in 2011. The next year state lawmakers established a controversial trophy wolf hunt, which included the use of dogs. Hunters killed 654 wolves during three consecutive hunting seasons.

Via a federal court ruling, protections for wolves were restored in 2014, thus preventing the state to use hunting seasons to manage the population, and allowing the population to stabilize on its own – a natural development which occurs when generally left undisturbed by humans (not managed via hunting, trapping, and hounding).