Professors lead squirrel studies with broader applicability.
By Sarah Kocher
You could say Wesleyan biology professors Cody Arenz and Gary Gerald have gone a little nuts.
Nevertheless, the pair has been radio-tracking campus squirrels since a revamped entry-level biology course debuted in the spring semester of 2015. The goal: field biology in an urban setting.
“Being at Nebraska Wesleyan… it’s a challenge to just dart outside, watch some mountain lions and dart back inside in a three-hour lab period,” Arenz said. Fox squirrels, as wild, fully-functioning, non-migrating, perpetually active and non-threatened mammals, are easy to trap and track.
“People don’t think of this area as being a habitat, but it is for squirrels,” Gerald said.
According to Wesleyan senior Katherine Ternent, who is continuing the study for the 2015-2016 school year and hopes to present her research in the spring, trapping the squirrels was a matter of coaxing them into live bait cages with oats and peanut butter. After catching a squirrel, the professors and students let them run from the trap into a bag with a hole in one end. When the squirrel stuck its head out, it received a collar tracker. The collar unit works much like a metal detector: the closer the squirrel, the louder the beep emitted by a signal-receiving tracking antenna. Of the 45-50 squirrels Arenz and Gerald estimate are present on campus, 20 were collared in this manner.
The information gained from the tracker, however, is minimal.
“The research tracking gives us identity and location information, and that’s really it,” Arenz said. “It’s valuable because you can turn that into a database of information where you can answer lots of questions.”
Some of these questions include ones about home ranges, sexual differences in movement or position, and particularly anti-predator behavior. In the last case, the students were more than qualified to fill in as predators. Many of these students chose to study flight initiation distance, or FID. FID involves squirrels hedging their getaway bets; for instance, the closer a squirrel is to a tree, the closer this squirrel may allow you to get.
“Animals used to be thought of as automatons… information in, information out,” Arenz said. “We’ve discovered over the past several decades that that’s not the case.” Rather, animals have a decision-making process through which they can evaluate variables, and the prediction, Arenz said, is that they will then act in an optimal fashion.
What’s more, the study’s applicability extends beyond city squirrels. Wild squirrels, of course, will follow the same basic pattern, but Arenz argues that the flight initiation pattern could extend beyond squirrels.
“There’s been enough research on anti-predator behavior that we think some of this same kind of logic can be applied to white-tailed deer [and] turkey,” as well as species closely related to the squirrel, such as marmots and prairie dogs, Arenz said.
This information is valuable to those looking to hunt, but equally valuable for those looking to protect.
“One of the things that we can ask of squirrels—that are not a species of concern—that has broader applicability is being able to find the location data of these squirrels with this many studies over… a long-term kind of data set,” Arenz said. “We can evaluate really small-scale changes in home range or position in response to a lot of different variables.”
Scientists and preservationists can take this information and use it to ask questions about how species will react to human activity. How close can humans be? How often can they be there? At what time can they be there? What level of human activity can any one species tolerate?
“It’s more challenging to test that out on endangered species. We can do it on the squirrels,” Arenz said. “With what level of human activity do we start seeing a change in behavior in the squirrels? And then we can infer that back to a species that we care more about as to whether it’s having an immediate effect.”
Arenz and Gerald plan to continue this project into the forseeable future. As they gather more data, Gerald said, they can explore more variables, and the applicability of squirrel research can only grow.
And, as Ternent said, it’s better than petri dishes any day.
About Sarah Kocher
Sarah Kocher is a NEBRASKAland contributing writer born and raised in Lincoln, Nebraska. Her sense of outdoor adventure was cultivated on fishing trips with her mother in search of the state-record perch, on family road trips, and in lab time for environmental science classes. She is working toward her bachelor’s degrees in English and journalism at Augustana College in Sioux Falls, South Dakota, and finds that the school’s major flaw is that it is not in Nebraska.