This summer, two Trent students will be returning to the Yukon to continue their research on arctic hares.
Melanie Boudreau, a student in the second year of her PhD, and Jacob Seguin, currently in his fourth year of his undergraduate degree, will be spending six months in the Kluane region, analysing the ways in which predation stress impacts the hares and their population cycle.
An additional research project focused on the effect of stresses passed onto offspring will be conducted as well. Both projects are operating under the supervision of Canada Research Chair in Terrestrial Ecology and Associate Professor Dennis Murray.
“I’m looking at how snowshoe hares respond behaviourally, physiologically and energetically to perceived predation risk,” said Boudreau. “It’s not just an effect of predation either, this study is wholly based on perceived predation risks, so avoiding predators. How do animals do that and how does it associate with the cycles we’re seeing?”
“What we’re testing is stressed hares versus hares just experiencing normal risk from predators in the area. In order to increase stress levels or maybe exhibit some sort of response in a treatment hare, we would expose them to a predator on a regular basis. For us that means exposing them to our analogue coyote, which would be a dog.”
Seguin happened to have an Australian cattle dog, who happened to fit the part perfectly. The analogue coyote is introduced as a predatory threat to a selection of hares, 25 control hares and 25 hares that will be introduced to a predator, each fitted with tracking collars, and the results are catalogued.
In order to analyse the presence of predation stress, the hares are trapped and fecal samples are analyzed. “Stress hormones will actually come out in poop, so that’s how we measure that,” said Boudreau, adding that in order to get accurate readings on stress caused by predatory threats, she and Seguin are looking for ways to minimize other sources of stress.
The goal of it all is to examine the implications of what Seguin called the “sub-lethal effect” of predators; behavioural changes that result from encounters with a dangerous predator, such as a tendency to stick to areas with more undergrowth to act as cover. Such a change in behaviour could have an effect on the quality of food that the hare consumes, potentially changing the likelihood of its survival.
“There’s two things a predator can do to a prey,” he explained. “It can kill it, so there’s the direct lethal effect. That prey is obviously affected because it is dead. Alternatively, if that prey escapes, is stressed and changes its behaviour.”
This summer will also mark the beginning of a second project, Seguin’s Master’s project that will be focusing on the offspring of the hares observed in Boudreau’s study. This is an examination of maternal effects, which Sequin described as “any effect that the mother has on her offspring’s ability to survive and reproduce. […] Behaviour or morphology or survival differences in the offspring that are not caused by the mother’s genetics.”
“If we take a mother that has had that hormonal stress response and we take her babies but we don’t actually let her babies be directly exposed to a predator, we want to see if her stress carries over to her offspring.”
The studies are an attempt to replicate lab results in a field setting, a process that is far from easy due to the unpredictability and lack of variable control in the field.
“It’s kind of difficult because what we’re trying to do is take lab results that have been shown in snowshoe hares and see if they apply ecologically in the real world,” said Seguin. “That’s essentially what it boils down to. We take ideas and theories that have shown that a snowshoe hare’s body can respond in a certain way to a predator being near but what matters is if it does that in the wild and if this system actually responds in real time.”
Referring to the region as “the wild” is by no means an understatement. “We do all of our work in the Kluane region, it’s about two hours West of Whitehorse, in the Yukon,” said Boudreau.
The base for their research is known as Squirrel Camp, and it is located about 20 kilometers from a research station operated by the Arctic Institute of North America. There are usually between 10 and 15 researches are at Squirrel Camp, most of whom are studying the squirrel population in the region, hence the name.
This summer will be the second the two have spent researching snowshoe hares in the region, with Boudreau’s study slated to finish after a final trip to the region next year. Last year’s segment was a three month text period for working out the details of the operation.
“Last summer was a preliminary trial for my study,” said Boudreau. “Really it was a test of what I wanted to do and we’ve adjusted for this coming year based on the results from last year.”
Last year’s results also included an array of memorable experiences for the two. Both Boudreau and Seguin noted the experience of seeing a grizzly bear. “In the month of June we saw a grizzly bear every day. […] It was crazy. Really, really cool,” said Seguin.
Boudreau also felt that the beautiful mountain region itself was a highlight, as well as the experience of living at a research camp. “For me just the challenge of living up there was really exciting,” she said. “We live in a place that has solar panels for electricity and no running showers.”
The two will be leaving to fly out to the region on April 20, and will be spending twice the amount of time there this year compared to the last, staying for six months. “The reason we’re there longer this time is some of the testing that I want to do has to occur past the breeding season. They breed until September and we have to stay there later,” explained Boudreau.
Additionally, this year presents a special opportunity for studying the snowshoe hares, as it is a peak year in the population cycle. Peaks in population only happen once every seven to 10 years.
During their six months in the Yukon, their days will be divided into two types: Trapping days and treatment days. “A trapping day is really a trapping night,” said Boudreau. “Hares are most active at night, so we try to trap when they’re most active and we trap in order to minimize the time that they’re in traps.”
Boudreau explained that in order to keep the stressful experience of being trapped from interfering with the samples, a special effort is made to ensure that the animals are not in the traps for more than eight hours. Trapping is usually done in five-day stretches, approximately once a month.
“On those nights we start trapping at around 11 o’clock at night. We set all our traps and then we’ll check them at six o’clock in the morning,” said Boudreau.
Treatment, or telemetry days, involve taking the radio and tracking equipment along with a checklist of the hares that need treatment for that day. Once located using the tracking collars, the analogue coyote would be used to create a sense of predatory risk.
The trick for treatment days is to actually find the hares, a process that involves lots of hiking, for as Seguin explains, “the [hares] that are being treated have to be very separate, they cannot be nearby to the hares that we’re using as our controls. You have to make sure you have your groups of hares far enough away from each other that you don’t accidentally run the dog near one that’s not supposed to get it.”
Both Seguin and Boudreau are honoured to participate in a field of study that has such a history in the area. “I feel privileged to be a part of this ongoing study. There’s a legacy there,” said Boudreau.
“There’s been 30 years of renowned biologists working in the place that we get to go and continue the work that they’ve done,” added Seguin.
“Ultimately is what is cool is that we get to take these theories and all the hard work that has been going for 30 years and relate it back to understanding how Canada’s boreal forest actually works. It’s like one of the trademarks of our country, this huge boreal forest, and we get to contribute to how we understand how it works.”