WOLVES & ECOSYSTEM HEALTH

wolves & ecosystems

It is widely acknowledged that wolves play a crucial role in maintaining species diversity and ecosystem health.

Killing wolves ignores repercussions on wildlife communities and ecosystem functions.

For instance, a healthy population of wolves on the landscape can help to maintain ungulate health by removing diseased animals, and also by limiting disease build-up and transfer by keeping the animals they hunt moving across the landscape to avoid predation.

This helps prevent large numbers of ungulates (i.e. deer, elk, moose) from gathering in one area, which can result in the overgrazing and over-browsing of plants, which then impacts many other species.

Large, stationary herds of ungulates are also at increased risk of spreading diseases and parasites more swiftly through their population.

Smaller herd sizes and continuous movement reduces grazing and browsing pressure on plants, allowing for increased growth rates and more diversity. Healthy vegetation benefits a variety of species of insects, songbirds, fish, amphibians, and mammals.

Wolf-kill programs have repercussions on all levels of the food chain.

Long-term and wide scale killing of large carnivores can cause ecosystem-wide adverse ecological effects.

Studies in Yellowstone and Banff National Parks have shown that where wolf populations have been extirpated in North America, a cascade effect is observed in which small mammals, fish, insects, birds, amphibians, ungulates, tree species and vegetation all suffer. Fortunately, wolves are still present in both parks today, enriching them in ways that are invaluable and irreplaceable.

Where wolf populations are heavily hunted, there is often a corresponding decrease in the complexity of ecological processes and species diversity. This occurs due to the myriad effects, both direct and indirect, that wolves exude on every level of the food chain.

See publication in Science: Trophic Downgrading of Planet Earth by James A. Estes et al. (2011).

Some of the ecological benefits of wolves include:

Wolves provide year-round food resources to many scavenger species (birds, mammals, insects), which contributes to species diversity;

Wolves facilitate movement of their prey (grazing animals) across the landscape, which promotes more plant growth and diversity (“ecology of fear”);

Wolves help keep the animals they hunt healthy by keeping them in smaller groups that are on the move, and by selectively hunting vulnerable prey, including diseased cervids (deer family), which can help to minimize and slow the spread of Chronic Wasting Disease and other infectious agents;

Wolves contribute to regulating the behaviour, abundance, and distribution of important mesopredators such as coyotes and raccoons.

In addition:

Wolves are highly sentient beings with strong family bonds. They have intrinsic value, as individuals, and as family-groups;

Wolf kill programs ignore the resulting negative impacts on wolf genetics and family social structures;

Killing wolves can lead to increased levels of conflict with people and livestock;

Wolf kill programs distract the public from the ongoing destruction of Nature and the failure of adequate land protection;

Wolf kill programs ignore scientific evidence and public efforts towards effective non-lethal approaches to living alongside wolves;

Wolf kill programs dishonour our relations with non-human animals.

Photo: Peter A. Dettling