A gray wolf (Photo by MacNeil Lyons/United States Fish and Wildlife, Midwest Region via Flickr/CC-BY-SA 2.0)
As the Montana Fish, Wildlife and Park Commission meets on Friday, among the most contentious and consequential decisions it will make is how to implement new legislative tools, granted by state lawmakers, to manage wolf populations, against the backdrop of more than 26,000 public comments on proposed changes to the wolf harvest.
Lawmakers passed a number of bills that increased the options for FWP to control wolf populations, including increased number of wolves to be harvested, an increased bag limit – or the number of wolves a hunter can take – as well as trapping and snaring.
Lawmakers and some members of the public say that wolf predation is hurting elk population and other game species. However, while that’s taken as fact in some Montana circles, research from the FWP studying predator-prey relationships between elk and other ungulates and a variety of carnivores show that wolves play no greater role than other predators. In fact, researchers found that several other species, mountain lions and black bears, may make more of an impact. Furthermore, the statistical link between wolves and decreasing elk herds is weaker for them than some other predators.
Complex science, statistics
Saying anything definitive or absolute about the relationship of different species in Montana is difficult. The expansive topography, coupled with different types of predator and prey in any area, is highly variable.
However, a March 2020 study performed by researchers from Montana State University and the FWP, “Evaluating carnivore harvest as a tool for increasing elk calf survival and recruitment,” examined the elk populations and what impacted their survival and numbers.
The report acknowledges that variability in elk herd numbers, carnivores and weather present researchers with a challenge of saying anything definitive about the overall state of predators or carnivores in a state that stretches from the steep, densely forested Rocky Mountains in the west to the wide-open beginning of the Great Plains in the eastern part of Montana.
“What we have in much of Montana is extremely complex – we have elk, moose, deer, sheep, and some pronghorn thrown in there, along with bear, lion, lynx, wolves. A simple linear relationship in that mix is hard,” said Brian Wakeling, game management bureau chief for the FWP. He was not part of the 2020 study.
He said that on top of the ungulate-predator relationship is the role of human activity, both development and hunting, which adds another layer to the question of the health of elk populations.
Researchers can also be challenged to estimate exact carnivore numbers in certain locations because of their wide territorial patterns, solitary nature or elusiveness.
Wakeling said even the time of year can make a difference in predator behavior. For example, when bears are not hibernating, there are not as many coyotes and more red fox in bear country. However, when bears hibernate, coyotes move in and hunt for fox.
“You see those dynamic relationships all the time. Nothing is independent of those interactions,” Wakeling said, which means that understanding any predator and prey species is extremely complex.
And there are relationships that are also well understood, for example, as prey populations, like elk, decrease, so too, usually do the predators dwindle because food is scarce, Wakeling said.
“Hunting folks talk about the good old days when animals were more plentiful,” Wakeling said. “But it’s always been the case that animals are more abundant at certain times than others. Fluctuations are common. What we’re trying to do is keep populations stable over time.”
However, by looking at several areas and different predators, the report said that no single predator species – bear, mountain lion, lynx or wolf – plays a dominant or outsized role in reducing elk population overall. But, those same predators may play larger roles in certain, specific locations where elk and other ungulates roam.
Bitterroot, Clark Fork study
The study looked at the Bitterroot and Clark Fork areas because wildlife managers had reduced mountain lion populations there previously in an effort to boost the elk population. Because wolves had also been introduced there in the early 2000s, it served as a good area to study multiple predator interactions with elk.
The research found that environmental conditions, especially when calves were young, and also the conditions when the elk calf is in utero, played a much greater role in elk population numbers than any particular carnivore.
“Cold and wet springs are thought to be a risk factor for elevated neonatal mortality, as environmental conditions interact to predispose neonates to the effects of illness, delayed green-up and increase the risk of predation,” the report found.
Also, summer precipitation was shown to have a large role in the growth of elk herds.
“We also found evidence … that dry summers interacted with particularly severe winters to diminish calf survival (in the first year),” the report finding said.
The research also suggested that summer conditions play a larger-than-expected role not just because of the necessity of young calves to grow healthy, but also as the herd prepares for the food-poor winters or as females prepare for to carry elk calves in utero.
While the research confirmed that elk populations generally grew with a lower number of black bear or mountain lion, the researchers didn’t necessarily find that link with wolves, except in the case of severe winters. The researchers hypothesized that cold, severe winters sent wolves in search of more food, ostensibly preying on young elk.
Wakeling said the research is consistent with what he’s seen. Wolves tend to strike elk more in the winter months. However, a wolf’s diet may be more variable than other carnivores. For example, a wolf in western Montana may hunt elk, while in eastern Montana, it would stalk more white-tailed deer.
“For example, bears come into conflict with humans because their diet is more diverse and they have the ability to eat things that becomes a challenge – our garbage, our grain bid, bird seed in the feeder or a fruit tree can be an attractant,” Wakeling said. “Wolves may pursue or get into a beehive infrequently, but they’re far more likely to consider dog food than a mountain lion.”
He said wolves may be to blame in public perception because people believe there has been an elk population drop during the time that wolves have been re-introduced.
“I don’t have a definitive answer, and there may not necessarily be a definitive answer,” Wakeling said. “But my perception is that wolves are the most recent thing in the marketplace, and that coincides with the population we’re most interested in, elk.
“We’re always looking for correlations. A prey population is going down and now we see a new predator and people perceive the answer.”
However, he said that what appears to be the answer may not be correct. He notes that wolves tend to be more visible than mountain lions, but population estimates peg mountain lions as more plentiful than wolves.
“We stress that more work is need to understand the relationship between minimum wolf counts, wolf abundance and vital rates,” the study said.
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