UND Today

University of North Dakota’s Official News Source

In search of North Dakota’s tiniest mammal

Lynda LaFond, biology Ph.D. candidate, studies shrews, expanding on what little research exists on these rarely trapped critters

Ph.D. candidate in biology at UND Lynda LaFond has centered her research on shrews, small rodents that are rarely caught and, thus, shrouded in obscurity. Photo by Dima Williams/UND Today.

In early summer of 2018, when Lynda LaFond would leave for Oakville Prairie, a nearly 1,000-acre swath of grassland managed by the University of North Dakota, the sun would barely break the dreary horizon.

She would reach the field station, lying some 20 miles west of Grand Forks, by 5 o’clock in the morning. In the next 10 hours LaFond would check over 700 traps that she had set to capture small mammals.

“For a couple of weeks, it is very, very hard,” said LaFond, who is pursuing a Ph.D. in biology at UND after obtaining bachelor’s and master’s degrees at Bemidji State University.

Once all traps are emptied and restocked with bait of peanut butter and ground hotdog meat, LaFond would drive back to campus to dissect the catch. It was a meticulous, exigent exercise that would last late into the night. The following morning, for five days in a row, she would repeat the routine.

This hectic schedule is part of LaFond’s doctoral research on the impact fire wreaks on the communities of small mammals. Portions of Oakville Prairie are burned every four years as part of UND biology professor Kathryn Yurkonis’ continuous examination of how vegetation responds to fire. Months after sections turn to ash and begin to regrow, LaFond’s trapping efforts commence.

In 2018, the first season for LaFond, she captured meadow voles, deer mice, and jumping mice, rodents typical for North Dakota. But then, one day, inside the traps she discovered several species of shrews. At the time, though, she could not tell them apart – they are, after all, some of the tiniest mammals in North Dakota.

“To me, it is very exciting to have captured these small mammals,” LaFond said.

Two-grams catch

What is even more thrilling is that after teeth count and DNA sequencing  in UND’s Vasyl Tkach’s lab, she identified specimen of particular concern for the state and of little familiarity for biologists – the arctic shrew and the pygmy shrew, the smallest mammal in North Dakota.

“I have captured arctic shrews before, but I have never captured a pygmy shrew,” LaFond said. “[Pygmy shrews] only weight about 2 grams. We don’t know much about them because they normally do not get captured. If they do pass on in the prairie because of natural causes, you are not going to see them because they are so small. They are very, very little.”

What is known about these teeny, mole-like rodents with long snouts and rangy tails is that they maintain quite a frenzied lifestyle. Their metabolism churns so rapidly they need to chomp insects almost incessantly in order to stay alive. Sleep amounts to a few seconds of slumber, LaFond said, before shrews snap back into the non-stop hustle of survival.

“They have to eat or they will die,” LaFond said, adding that, despite the constant effort, their lifespan stretches to 12-14 months. That is if they do not turn into a meal for hawks or owls.

Cats would also prey on shrews, but would not eat them. The venom sacs above the shrews’ teeth, an ancient anatomic trait, make them a rather insipid snack, LaFond said.

Pygmy shrews (left) and arctic shrews are among the smallest mammals in North Dakota, weighting just several grams, a mass that, nonetheless, needs to be sustained by constant eating. Photo by Dima Williams/UND Today.

Big leap, small creature

In North Dakota, pygmy shrews were previously caught only in the counties of Ramsey and McHenry, according to The Mammals of North Dakota, a comprehensive book by UND Professor Emeritus Robert Seabloom.

LaFond trapped them in Grand Forks County.

“That is a significant finding in itself because now we get to shade that [area] and say, ‘Yes, they are found here [as well]’,” she said.

Unlike pygmy shrews, arctic shrews have been documented more extensively across the state. Yet, both species appear on North Dakota’s conservation priority roster but little recent research has studied their habitat and habits.

LaFond’s work, however, could change this. She hopes to assemble miniscule radio collars to clasp around shrews in order to track their escapades throughout the prairie.

“I am hoping to be able to get every couple of seconds’ worth of information for 24 hours, so I can see how they are moving through the vegetation,” she said.

Before she begins this portion of her research, though, LaFond is now preparing for another season of trapping come the end of June. But selecting five straight days with agreeable weather to set traps could be a challenge. In 2018, an unexpected summer shower interrupted LaFond’s schedule.

“We are in North Dakota and little rain storms can turn into big rain storms pretty fast,” she said. “It is kind of frustrating.”

Yet, the big stride LaFond is undertaking in understanding these small critters is worth all the trouble.