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Kristine Luck, a second-year veterinary student, looks for parasites in the intestines of wolves.

Student pans for worms in wolverines

The wolverine is an animal so elusive that even some wolverine biologists have never seen one alive in the wild.

I spent my summer learning about this mysterious animal in Dr. Emily Jenkins' parasitology lab at the Western College of Veterinary Medicine (WCVM). I had the not-so-glamorous summer job of sorting through nearly 200 intestines of wolverines that had been collected in the Yukon and Northwest Territories (N.W.T.) over the past nine years.

It's the first time in decades that researchers are examining parasites found in wolverines from these major regions.

Hunters in Canada's northern territories harvest wolverines for their fur, but little is known about the parasites infecting these animals.

By identifying parasites in the wolverines, we can understand the ecology of these parasites as well as the role of wolverines in the northern ecosystem.

Jenkins' research focuses on northern ecosystems — the "hot bed" of warming for Canada. "Studying these areas can give us a heads up about what climate change will do in other areas of the world – especially where the climate warming isn't as rapid and isn't accelerating as quickly."

Changes in climate can potentially lead to changes in parasite distribution and abundance.

"For wolverines, the High Arctic populations are probably as close to untouched as we can get. Looking at the North as an outgroup for comparison with the South [may indicate] how things were before we interfered," Jenkins explains.

Ironically, my project came about because there were too many samples – a problem that most researchers would envy. The freezers in the N.W.T. were overflowing with wolverine tissues and something had to be done with them.

As Jenkins explains, the suggestion was made to look for parasites in the wolverines' intestine samples since no one had published any literature on this topic since the 1960s and 1970s.

"The climate baseline has shifted and the world is a different place. There's a lot more resource extraction, and so it was time to look again," says Jenkins.

Worms, predominantly Baylisascaris and Taenia, were isolated from samples taken in the N.W.T and the Yukon.

Wolverines are high-level predators and scavengers and at the top of the food chain. The parasites that they carry can provide us with information about what the wolverines are eating and about parasite transmission through the entire food chain.

"Hopefully our data will be a piece of that puzzle in terms of understanding the health status of the wolverine population," says Jenkins.

In contrast to the general opinion that parasites indicate a health problem, she suggests that if a population contains a high prevalence and intensity of parasites, the population may actually be doing very well. Increased parasitism could be a direct result of having ample access to the intermediate hosts that are giving the wolverines these parasites.

Last summer, two Grade 8 boys searched for parasites in 10 wolverine intestines from the N.W.T. as part of their science fair project. I'm expanding on their efforts and my project is supported by the Government of the N.W.T., the WCVM Wildlife Health Research Fund and the U of S Undergraduate Summer Research and Leadership program.

So, like many prospectors before me, I headed to the Yukon. In June, I travelled to Whitehorse with Rajnish Sharma, one of Jenkins' graduate students. We worked with a team led by Dr. Jane Harms, an Environment Yukon wildlife veterinarian, to conduct necropsies on wolverine carcasses from the fur harvest.

Harms and her colleague, Drs. Brett Elkin and Iga Stasiak of the Government of N.W.T., and wildlife biologists Thomas Jung and Robert Mulders graciously provided us with access to these samples.

We brought 99 intestinal samples back to Saskatoon, and I went straight to work.

It's like panning for gold, but the prize isn't as valuable to most people. The two main worms that I found were Baylisascaris and Taenia.

A wolverine could get infected with Baylisascaris, a roundworm, by eating an infected small mammal such as a rodent or by swallowing eggs from feces in the environment.

Using DNA sequencing, I identified two species of Taenia tapeworms infecting the wolverines. For one, T. twitchelli, wolverines get it from eating porcupines. For the other, T. krabbei, wolverines get it from hunting or scavenging moose or caribou as intermediate hosts. This parasite has never before been recorded in wolverines.

The final stages of my project are comparing the prevalence of the parasites among the regions and to look for any differences.

This project would probably have been too messy, smelly and gross for most people — but for me, the research has been fascinating and extremely worthwhile. My tenacity has even earned me high praise from my supervisor.

"You're very cheerful about going through guts — it's very impressive," says Jenkins.

It turns out that searching for worms can be rewarding, even if they're not exactly worth their weight in gold.

 

Kristine Luck of Calgary, Alta., is a second-year student who was part of the WCVM's Undergraduate Summer Research and Leadership program in 2014. Kristine's story is part of a series of articles written by WCVM summer research students.
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