Coyotes are well known for their adaptability and deceptive ways. This has helped the cunning creatures recolonize much of their former habitat and spread to the fringes of human-dominated landscapes where they were previously absent.
While these medium-sized meat eaters, known as mesocarnivores, can be restless around people, they take risks around large, non-human predators. New research shows that coyotes often try to steal or scavenge prey killed by mountain lions, such as deer and elk. But this risk-taking comes at a cost: it’s not uncommon for cougars to eat coyotes.
Researchers in Oregon recently found that mountain lions killed about a quarter of all coyotes in a study area. Competition for prey may be the reason: the study found that elk meat, from animals killed by cougars, made up more than half of the coyote’s diet.
This article, published in Proceedings of the National Academy of Sciences, is part of a series of recent studies showing that medium-sized carnivores often take such risks, far more than previously thought. Globally, large carnivores, including cougars and wolves, are responsible for approximately one-third of all mesocarnivore deaths. Meanwhile, stolen prey made up about 30% of the diet of these small predators, which include coyotes, bobcats and black bears.
“It’s certainly possible that, even if it’s risky, the coyotes just can’t help themselves” in the face of freshly killed deer and the like, says Laura Prugh, a University of Washington professor and author of a 2020 article in Ecology Letters that addresses these relationships. “It is also possible, however, that they are able to assess the risks, for example, based on the freshness of the large carnivore sign or by being more vigilant.”
This risk-taking, or what Prugh calls “enemies with advantages”, plays out differently depending on the ecosystem and the species concerned. These articles consistently note that trying to remove a carnivore from a landscape or encourage another to return is likely to have consequences that are difficult to predict.
“The presence of cats affects coyotes. The presence of coyotes affects cats. Wolves affect coyotes and coyotes affect wolves,” says University of Wyoming researcher Kevin Monteith. “None of their actions are independent of each other.”
The calculation of a carnivore
Prugh came across the phenomenon she calls “fatal attraction” while studying gray wolves in central Alaska. The mainstream thought held that apex predators controlled smaller predators. But when snowshoe hare numbers plummeted in her study area and coyotes began to hunt slain wolves significantly more, she wondered if mesocarnivores could really benefit from the presence of predators in the area. Mountain peak.
And they kind of took advantage of it. She found coyotes lingering in areas where there were packs of wolves in an attempt to kill. But she also found that the risk of coyotes being killed by wolves was increasing.
“So maybe these killing sites aren’t actually just a free lunch,” she says.
Why all this focus on coyotes? They are among the biggest contributors to the mesocarnivore population in North America. They range from Alaska to Panama, and maybe even further south. They are intelligent, good at breeding, and adaptable, and they are often more willing to take risks for food. (Learn more: Coyotes have expanded their range to 49 states and beyond.)
In the PNAS study, researchers attached collars to coyotes, cougars, black bears and bobcats, and installed surveillance cameras at kill sites to see which animals were visiting and track their movements. Results showed that black bears avoided cougars and rarely visited kill sites. During this time, the lynx cared little for the lions or their food.
Nearby, in the Sagebrush and Juniper Mountains of Wyoming, researchers found that coyotes generally avoid areas where lions live. Data from radio-collars showed that coyotes stayed away from areas with trees and rocks that help cougars hunt, unless they smell or smell food, says researcher Mitchell Brunet, author from an article recently published in Ecology and evolution.
The Wyoming and Oregon researchers found that while mountain lion kills were a substantial part of a coyote’s diet, coyotes were not disproportionately more likely to die while foraging at a new site. It’s possible, the researchers say, that when coyotes know they’re in a high-risk area, they stay alert.
“Coyotes are very vigilant” at kill sites, says Taal Levi, a professor at Oregon State University, co-author of the recent study in Proceedings of the National Academy of Sciences. “They are usually not alone. There can be alarm calls, multiple eyes and ears watching, and when you have a group of coyotes you have some advantage in defending against first identifying a cougar and defending against.
Prugh’s meta-analysis of 256 studies from around the world showed great similarities in that apex predators killed many mid-level predators, but also that each relationship was a little different. Cougars killed coyotes and often ate them. Wolves tended to kill coyotes, and sometimes decapitate them and bury their heads in the snow. Brown bears in Europe not only steal 40-60% of Eurasian lynx kills, but scare cats away. The rate at which lynx lose food to bears is so high that Pugh calls it a “bear tax”.
As coyotes in North America die off cougars and wolves, they also survive by raiding in teams, providing more lookouts, and adapting to living near humans.
Other mid-level carnivores are not always so lucky in some parts of Africa. Every additional apex predator, she says, including lions, hyenas, leopards and cheetahs, puts “super additive” pressure on mesocarnivores by “shrinking that enemy-free space.”
A tangled web of fear and hunger
The reliance of mesocarnivores on top predators — like coyotes depend on cougars — could show that predators have less of an impact on big game populations or more, depending on who you ask, Levi says.
“If you hate them, you could say we have to kill cougars because not only do they kill deer, but they support a plentiful coyote population that also kills deer,” he says. “Or you could say we have to keep cougars because they’re distracting coyotes from deer by feeding them elk. But both are missing parts of the story that are still uncertain.
Researchers still want to know if scavenging at kill sites actually increases the risk of death for mesocarnivores. It is possible that species like coyotes are simply at risk of being killed by mountain lions or wolves, no matter where they spend their time.
Scientists know, however, that while fear of death is a motivator even for predatory species like coyotes or foxes, so is hunger.
“On a per capita basis, if you have a one in five chance of dying, that’s really bad,” Levi says. “So you would think they would go to great lengths to avoid that. But I guess it’s really the relative risk of being killed versus not being killed that matters.