Quirks and Quarks

Dangerous, difficult and disgusting — Tracking cougar kills gives insights into the big cats

Researching cougar predation in southern BC could help us understand how increasing human activity is influencing the big cats' behaviour. And there were kittens.

GPS helps guide the researchers to the carcass, but often they smell it before they see it

A highlight of Siobhan Darlington's research during the summer of 2020 was discovering a den with two cougar kittens. Both were measured, tagged and safely replaced. (UBC Okanagan Cougar Project)

Originally published on September 12, 2020.

Tracking cougar kills in the wilderness of southern British Columbia involves some risk, some challenging terrain, and can be an assault on the senses. But for biologist Siobhan Darlington and her team, it's a great way to learn more about the often mysterious big cats.

"They're really an understudied, elusive species," Darlington, the coordinator of the University of British Columbia Okanagan Cougar project, told Quirks & Quarks host Bob McDonald. Humans rarely see cougars, but cougars are being increasingly affected by human activity as the wilderness shrinks.

"One of the main objectives of our study is to understand the role of human activity, such as roads, forestry, hunter, harvest, and even wildfires, and understanding the roles of those features in shaping cougar distributions, their behaviour, and their diet."

The strategy the team is pursuing to this end is to find and study cougar kill sites, which can provide insight into all of these questions.

Members of the UBCO Cougar project collect data at a cougar kill site. They found cougars taking deer, elk and moose as well as evidence of smaller prey. (UBCO Cougar project)

Finding the scene of the crime

The key to this study is a group of fifteen cougars who have been captured and fitted with GPS tracking collars. These allow the researches to track the cougars' movements with relative ease, said Darlington. "I do it from my laptop, and sometimes from my phone."

Darlington looks at the tracking data for places the cougars, who have home ranges that can stretch more than 100 square kilometers, visit frequently over a short period of time. These are often sites where they've cached a kill, and to which they are returning to in order to feed.

Then, the team heads out into the wilderness to find and study what the cougar has taken. The GPS gives approximate location of the kill site, but cougars do conceal their kills. So, in rough country and tangled undergrowth, this can still mean a lot of searching, said Darlington.

"That carcass could be anywhere. So we start looking for signs of predation, such as clumps of hair. We look for fragments of bone or teeth. Sometimes we find hooves sticking out of the ground."

If the weather's been warm, and the kill is a few days old, the search can be easier, said Darlington. "Sometimes I actually don't need my GPS at all. We joke that we just follow our nose and then we find the carcass."

A cougar kill site discovered by Siobhan Darlington's team (Siobhan Darlington)

Identifying the prey species tells the team what kind of animals the cougar is relying on in different environments, and they're interested if those patterns change in areas with lots of human activity. Cougar will take mule deer, white-tail deer, small moose and even elk, though they aren't common in the Okanagan. 

Forensic wildlife science 

But the kill sites can tell the researchers much more. Cougars establish latrines — Darlington says they're like 'litter boxes' — and analyzing cougar scat can tell them about what else the cougar has been eating that it doesn't cache, particularly smaller animals like beaver or birds. Scat can also be a source of DNA. 

The sites can also reveal what other wildlife is benefitting from cougar kills. Darlington and her team will often set up motion-activated cameras, which catch scavenging bears, birds and small mammals. This information can give real insight into the complex ecosystem web that cougars inhabit. Other cougars will also visit the kill sites of collared cougars, which gives some insights into cougar populations, said Darlington. "That tells us there are more out there than we think."

One highlight for Darlington during the summer of 2020 was not a kill site. It was a site that a female cougar who they'd previously seen in association with a large male, kept returning to. Darlington and the team visited the location and were delighted find the mother in her den, and to hear kittens inside. "They must have been only three or four days old." 

The team tracked the den down again about a month later, and were able to visit when the mother was absent. They extracted the kittens, sexed and weighed them, and put small ear tags on them to help identify them in the future.

Sure it's cute now, but this cougar kitten will soon grow up to be a lethal predator (Siobhan Darlington)

"They were very feisty, especially the female," said Darlington. Her research assistant wore thick gloves for protection from the kittens' sharp claws, but they weren't enough. "Kayla got a little bit of a scratch on her from this cat, and we joked that she'd now been attacked by a cougar and she could tell her friends she survived."

Keeping an eye out for a predator

Of course hanging around the kills of a potentially angry and dangerous big cat is not for the faint-hearted. The team takes prudent precautions.  "We very seldom see them. The cats usually hear us coming. So to be safe, we bring bear spray out with us in the field and we always go in groups of at least two people, but we make quite a bit of noise as we approach the site." 

And as it turns out the stealthy cats aren't usually stalking them from the forest.  The GPS tracking data indicates the animals won't return to a kill site until several hours after the humans have departed.

Darlington is hoping that as they continue to gather data, and track more cougars using this technique, they'll learn more about these fascinating animals and perhaps gain some insights into the potential for human-animal conflicts as we continue to intrude on their wilderness habitat.

Produced and written by Jim Lebans.