Student researchers aim to save declining moose population

This time of year, Minnesota moose hunters are usually bringing home the last of their kill, but this year, there was no hunt in the first place. The rapid decrease in the moose population caused the Minnesota DNR to call it quits for this fall. [1] According to the DNR, 10 out of 34 collared moose calves have died since May. On top of that, the Minnesota moose population dropped from just under 9,000 moose in 2006 to the current 2,700, including a 52 percent drop since 2010.

UMD has been researching this alarming population decline for the past four years, headed by biology professor Ron Moen and his undergraduate and graduate researchers in conjunction with UMD’s Natural Research Institute (NRRI).

Read about what some of the UMD moose research team members are doing.

Tessa Tjepkes

Dressed in the typical seasoned scientist’s garb of an aged white coat and tight latex gloves, Tessa Tjepkes leans over her microscope and scrutinizes a sample of dried moose blood. She’s studying northern Minnesotan moose population genetics to see if there are signs of inbreeding. This mating dilemma can inhibit the animal’s ability to reproduce and cause genetic mutations in the calves.

Optimistically, she sees these genetic problems as the easiest of the moose problems to solve.

“If by chance there is a lot of inbreeding, and if they just need to bring in different individuals from a different population to get genetic diversity back into the population, it could be just a simple fix like that,” she said.

Nevertheless, she speculates creating a bigger gene pool won’t keep moose around because the main problem is Minnesota’s warming temperatures. Moose require cold environments; above-freezing temperatures in the winter cause them to overheat because of their thick winter coats, according to William Ching-Hsuan Chen, a fourth year doctoral candidate involved in the moose population research project. [2]

“They might just have to move north because even bringing in new genes won’t fix their inability to tolerate heat,” Tjepkes said.

Although it could be too late to save local moose, Tjepkes said that “people can use (the team’s research[3] ) on moose populations somewhere else. It could definitely be useful for a lot of different things.”

Rachel Ward

Unlike Tjepkes, who is just starting her research, second-year graduate student Rachel Ward will finish her research this semester and present the results in her December seminar. For the last two years, she’s been in and out of the field, pinning down Minnesota moose browsing habits and figuring out if there’s enough available food to support healthy moose life.[4]

The two study topics go hand in hand.

“We could maybe say, ‘Is there enough food out there in the first place?’” she said. “Because, if there isn’t enough available, maybe they’re malnourished. But, if there is enough food and they’re still malnourished, are they taking the right (food)?”

Moose feed on trees. In the summer, they eat the leaves of deciduous trees. Their favorite leaves, according to her studies, grow on mountain maple trees.

In the winter, they chew on twigs and saplings, favoring those of hazel trees.

All in all, she said they eat over ten thousand twigs a day. A twig, in science terms, is equal to one mouthful, although moose can fit between five and 10 twig branches in their mouth at once.

Ward gathers browsing information from moose feeding stations she finds using the new tracking method she and Moen created.

She’s said it’s “more realistic from the moose’s perspective.”

Instead of using the old method and walking a straight transect through the woods, she picks an area and searches all around it.

“Moose do not walk in a straight line,” she said. “If you follow their tracks in the snow, it’s not straight … They might curve in a circle and then go around over here, or they might zigzag.”

William Ching-Hsuan Chen

When he’s not in waders and standing in a lake while gathering buried temperature sensors in the muck, William Ching-Hsuan Chen is in his office, analyzing the soil temperature data collected by these sensors. Other times, he’s using daily GPS location data from the moose tracking collars in order to create a computer model of moose movements, which is essentially a very detailed map.

“The ultimate goal is to take a movement path and to break it down into different behaviors,” he said. “So we can run the data through the model and the model will say, ‘The moose is browsing. The moose is resting. The moose is feeding or moving between rest sites.’ That kind of thing.”

This information will help the research team predict a moose’s interaction with various habitat types under different environmental conditions.

 For Chen, the importance of saving the Minnesota icon is based on a cultural perspective.

“For northern Minnesotans at least, moose are such an important part of being a Minnesotan,” he said. “If moose go, it’s going to be a great shame.”

Juliann Terry

Minnesotans are well acquainted with wood and deer ticks, but who knew about winter ticks? Terry certainly does, as this is her area of study. The first-year graduate student is looking at their habitat in comparison to moose location data in order to find the high-risk areas for moose to come into contact with ticks.

Winter ticks aren’t hot for humans, but they do crave moose blood. Come fall, they wait for a moose to walk by and then jump on them for a winter ride. In the spring, they mate and then fall off to lay their eggs in the soil.

“Moose get thousands of them,” Terry said. “They’re thought to increase (the moose’s) risk of being killed by wolves or susceptible to other disease or other parasites, as well.”

When the moose groom themselves of ticks, they also remove a lot of their fur, in turn leaving them more exposed to environmental dangers. Moose can also lose a substantial amount of blood to the sucking ticks.

“We’re not thinking that winter ticks are the main cause for the decline,” she said. “Different percentages every year are really affected by (winter ticks), but they’re a factor that make (moose) susceptible to something else.”

Terry said her results could be used to manage the moose habitat to keep them away from tick areas.

Yvette Ibrahim

It may sound like dirty work, but studying wolf scat is the best way to see what Minnesota wolves are eating — and they do prey on moose calves. Ibrahim is gathering samples of wolf scat and aims to determine the impact wolves have on the moose population.

She digs through her samples under a hood in her lab, searching for moose calf hair. The hair follicles are distinguished by their small diameters, light colors and their unique scale patterns.

“I believe in nature taking its course, but that’s not possible anymore,” she said in reference to the importance of her research. “Humans have made such an impact. If we do nothing, we’re going to make it worse … We have an obligation to keep trying.”


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