The Relationship between Wolves and Elk: Are wolves decimating the elk population?

A lone wolf trots past a herd of elk.
USFWS Mountain-Prairie, Public domain, via Wikimedia Commons

One of the most common arguments in discussions of wolf management is the idea that wolves are decimating the elk population. It’s a logical thought. Wolves eat elk. More wolves must mean less elk.

This conclusion has shaped our wildlife management practices as well as our public perception of the wolf. But a lot has changed since the days of Little Red Riding Hood and the Big Bad Wolf. We’ve learned that things are rarely as simple as they may appear, especially in complex ecosystems and that there are many indirect effects that must be considered.

Wolves and elk have coexisted since long before humans showed up, evolving together and bringing balance to one another as well as to the ecosystems they share. We have often misinterpreted this relationship, applying our own logic and human experience and overlooking their part in the larger natural system.

Direct Predation

Let’s take a step back and look at the “more wolves equals less elk” idea. It is absolutely true that wolves hunt elk for survival, and about a million years of evolution has made them pretty good at it.

But even just looking at direct predation statistics, wolves don’t deserve the spotlight. Mountain lions, bears, and coyotes have been known to predate on elk just as much or more than wolves.

Idaho Fish and Game conducted a study in the winters of 2015-17, studying elk mortality. In the first two winters, 14% of the elk being studied were killed by mountain lions and only 3% by wolves. In 2017, the trend held true with mountain lions taking 16% and wolves 6%.

To provide some context for this particular study, the location is the panhandle of Idaho, one of the densest wolf populations in the country. It was conducted in the winter, when wolves kill the most elk because of their advantage in the snow. Finally, it spanned 2015-2017, near the peak of wolf population in the state.

It’s also worth mentioning that the human hunters kill more elk than wolves, but that’s a discussion for another time.  

Change in Behavior

As I mentioned above, direct predation is only the surface of the issue. The real impact comes from the wolves’ indirect effects on elk behavior.

The relationship between wolves and elk is ancient and complex, even more so than with other predators. While other predators may kill similar amounts of elk, their hunting strategies are more inconsistent, based on ambush or opportunity.

Wolves on the other hand are engaged in a constant game of cat and mouse with the elk. They are an almost constant presence in their lives.

Over time, the elk were able to learn how the wolves hunt and take steps to minimize their interactions with them. This shapes many aspects of their lives, determining their behavior and daily activity.

It’s important to understand that not only do wolves keep the elk population in check, they also keep them from spending too much time in one place. With wolves around, they are more cautious. They don’t spend too much time in one place and avoid open areas. This natural survival instinct not only protects them from predators but also from overgrazing, allowing their food source to grow back.

Yellowstone National Park from Yellowstone NP, USA, Public domain, via Wikimedia Commons

After the wolves were killed off, elk were without their natural predator for over 50 years. At first, their numbers skyrocketed of course, but they soon began to suffer from overpopulation.

Without the wolves, they were now able to graze without regulation. Elk lived longer and had more babies, which multiplied their effect on the landscape. They ate away entire prairies and valleys and then began to starve when the land could no longer support their numbers.

This of course had negative effects for the elk themselves in the form of disease and starvation. But it also hurt the surrounding environment through deforestation, erosion, increased risk of fires, and lack of biodiversity.

Having more elk than the land could handle caused problems for society as well by increasing deer-vehicle collisions and grazing on agricultural production land.

Local governments tried to solve the problem by encouraging elk hunting, but in time this made things even worse. The human hunters targeted the big strong bull elk, leaving behind the sick and weak. This led to herds that were large in population but weakened by disease and an ever-decreasing food source.

Trophic Cascades

Then the wolves were reintroduced. They hunted the elk, bringing their population back to a healthy size. More importantly, they targeted the easy prey – the weak and diseased members of the herd, making it stronger over time.

The elk remembered to fear open spaces, balanced their grazing time with time spent hidden in the forests. This allowed the vegetation to grow back, providing the food source that had been missing. In Yellowstone National Park, we see that within about ten years of reintroduction, both populations had leveled out at healthy numbers. The ecosystem was strong and balanced in a way that it had not been in many years.

Counts of wolves, elk, and bison in northern Yellowstone National Park from 1995-2016, U.S. National Park Service, Public Domain, via https://www.nps.gov/yell/upload/Wolf_Report_2016.pdf

The problem comes when hunters and tourists are no longer able to see herds of elk lining the streets and come to the conclusion that the wolves must have killed them all. In reality, they are there and healthier than ever before. It just takes a little more work to find them.

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