Black-tailed prairie dogs can carry fleas, which have been known to carry the bacteria Yersinia pestis – the causal agent of plague.
Black-tailed prairie dogs can carry fleas, which have been known to carry the bacteria Yersinia pestis – the causal agent of plague.

“Flea-finder” probes for plague in Grasslands

Endless skies, wild bison and real cowboys – all are a part of life in Grasslands National Park. My summer research has brought me to southwestern Saskatchewan, an area harbouring some of the only native prairie left in Canada — and potentially, plague.

Just like your own pet dog, black-tailed prairie dogs (Cynomys ludovicianus) can have fleas, too. These fleas have been known to carry the bacteria Yersinia pestis – the causal agent of plague. That's right – the same bacteria that caused the Black Death in Europe during the 14th century.

It sounds scary, but there's actually minimal risk to human health unless you have a habit of snuggling prairie dogs, especially the flea-infested sort. In Grasslands, only one confirmed case of plague in a prairie dog was recorded in 2010. Since then, Parks Canada veterinarian Dr. Todd Shury and his research students have been monitoring levels of plague-carrying fleas.

This is where I come on to the scene. Against the vast backdrop of the prairie grasslands, I scamper about the prairie dog colonies, manoeuvring my plumbing snake with a flannel "swab" down the burrow of each unsuspecting victim.

The cute, loveable, talkative prairie dogs remain unharmed. This process is akin to cleaning your ear with a Q-tip — except my prize is fleas, not earwax. Once I've captured my unlucky prisoners, I send them to the Public Health Agency of Canada's (PHAC) National Microbiology Laboratory in Winnipeg, Man. PHAC will then identify flea species and run tests to detect plague-causing bacteria.

Why is it so important to save the prairie dogs from impending Black Death? First of all, Grasslands hosts the only native black-tailed prairie dog population left in Canada and their conservation status is "special concern" under Canada's Species at Risk Act.

Tara Stephens, a wildlife population ecologist with the Calgary Zoo's Centre for Conservation and Research, has been studying the dynamics of prairie dog colonies in Grassland for eight years as part of the Husky Energy Endangered Species Program.

"Black-tailed prairie dogs are a keystone species because they create a unique mosaic of habitat across the landscape that increases the heterogeneity and biodiversity of Grasslands National Park," says Stephens.

These cute critters not only function as landscape engineers, home-builders and alarm systems, but they're also an important source of food for the black-footed ferret (BFF) — an endangered species.

Lauren Beaulieu, a second-year veterinary student, spent the summer in Grasslands National Park surveying the prairie dog population.

Ferrets also use abandoned prairie dog burrows as shelter, but they're not the only park patron that moves into vacant real estate. Burrowing owls, another endangered species, also claim the custom-built prairie dog homes as their own. Besides these two obvious beneficiaries, there are many more species whose livelihoods are connected to prairie dogs.

Stephens' research contributes to the science behind conservation of the black-tailed prairie dogs as well as the efforts to re-introduce black-footed ferrets. As she points out, Grasslands will use science to make informed management decisions, and that's one contribution she can make to help conserve this unique prairie ecosystem.

Stephens thinks it's vital to keep monitoring and expanding the plague-focused research; "We really have little understanding of plague ecology in Canada." She refers to the devastation that plague has caused across the border in American prairie dog colonies. "There's a spectrum of what enzootic and epizootic levels [of plague] can look like. It might take five or more years to catch a signal of plague in the system, especially if it's at enzootic levels."

Plague can be hard to find if it's not present at high levels, but this doesn't mean it's not doing any damage. To boost my chances of finding evidence of plague, I have been taking blood samples from dogs (pet dogs, not prairie dogs). Dogs will mount a sizeable immune response when infected with plague-causing bacteria but usually go on to lead healthy lives. Antibodies from the immune response remain in the dogs' blood, providing a marker to use in plague monitoring.

Plague in GNP has been elusive and this makes searching for it a bit tedious. Don't get me wrong, my job does have its perks. My commute to work is a peaceful hike, my office is the rare prairie grassland and my co-workers are chattering prairie dogs.

Stephens sums up the magical atmosphere in the southwestern park: "It feels so hidden, and I love that about Grasslands."

When it comes to being hidden, the plague is also doing a good job, which reminds me – I have to get back to finding fleas!

This research project is supported by the Western College of Veterinary Medicine's Interprovincial Undergraduate Student Summer Research Program, Parks Canada and the Calgary Zoo's Centre for Conservation and Research. Visit explore.org to see remote footage of the black-tailed prairie dog colonies.

 

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