Why a Squirrel's Personality Makes a Difference

Anyone who has ever watched squirrels at a bird feeder knows they don’t all act the same. Some are very bold and will relentlessly ignore birds and even people in order to snatch a meal. Others are less aggressive and will stay off to the side, prepared to dart in and grab seed when the opportunity strikes.

While it seems obvious to ascribe personalities to these captivating critters, actual scientific research about animal personalities is relatively new. Researchers at the University of California, Davis, have documented the personalities of golden-mantled ground squirrels for the first time. This species is common across the western U.S. and parts of Canada.

They found that squirrels showed four main personality traits: aggressiveness, boldness, activity level, and sociability.

“I wasn't surprised to find that golden-mantled ground squirrels show personality because I believe that all species, non-human and human, have behavioral traits that consistently differ among individuals—it's just a matter of time before we could go out and prove it,” lead author Jaclyn Aliperti, who conducted the study while earning her Ph.D. in ecology at UC Davis, tells Treehugger.

“I was surprised to find such clear and interesting connections between several personality traits and the ecology of this ground squirrel species. As with many scientific studies, our findings have led to more questions.”

Studying Animal Personality

It’s been only recently that researchers have studied personality in animals.

“While researchers have known for quite some time that individuals show consistent differences in behavior (personality), scientific studies quantifying personality across the animal kingdom really started to take off over the past decade or two,” Aliperti says.

Early studies offered scientific evidence that certain species have distinct personalities.

“We now know this as a fact for a diversity of species, from chimpanzees to mosquitofish,” Aliperti says.

“After a period of time in which researchers focused on why individuals differ in personality and how those differences are maintained in nature (it's in part hereditary, but also influenced by the environment), scientists began to focus on the consequences of personality for those animals, as well as their environment. It turns out, individuals matter in important ways!”

Assessing Squirrel Personality

For her experiment, Aliperti observed free-ranging golden-mantled ground squirrels (Callospermophilus lateralis) in four different scenarios that are standardized ways to scientifically assess animal personalities. (Researchers can’t administer a Myers-Briggs personality test to animals, after all, she points out.)

In one test, squirrels were placed in a novel environment to see how they would react. In this case, it was an enclosed box with holes and gridded lines. In a second experiment, squirrels are shown their image in a mirror and they don’t recognize it’s themselves.

In a “flight initiative” test, Aliperti observed how squirrels responded when they were approached in the wild. She recorded how long they would hesitate before then scampering away. And finally, Squirrels were caught and placed briefly, unharmed, in a trap to see how they reacted.

Aliperti and her colleagues then analyzed the results to see whether personality influenced factors such as the size of their home range and core areas, speed, and how they used perches. Access to perches, such as rocks, is critical because it helps squirrels spot and avoid predators.

The findings showed that squirrels with bolder personalities had larger core areas, and bold, active squirrels were faster than their counterparts. Squirrels that were bolder, more active, and more aggressive had increased access to perches. There was also an association between access to perches and sociability.

Normally an asocial species that isn’t reliant on interactions, golden-mantled ground squirrels have an edge when they indeed interact.

The researchers wrote that “within this asocial species, individuals that tend to be relatively more social seem to have an advantage.”

The results were published in the journal Animal Behaviour.

The Intrigue of Animal Personality

Aliperti began studying this particular squirrel species as part of a research study in Colorado in 2015. For the study, researchers marked animals with unique patterns so they could distinguish them through binoculars.

“During my first summer there, I noticed that some individuals were tricky to find, while others seemed to be everywhere, all the time. Some wouldn't let me get too close, while others were seemingly following me around!” Aliperti says.

“Because I watched and tracked each animal just about every day, I started to get used to their individual temperaments and decided to quantify and formally study personality in this species. This is the first study showing that this species shows personality.”

Of course people with pets have long known that their dog, cat, or frog has certain qualities that make up their personality. But Aliperti says she finds the study of animal personality intriguing because it helps people relate to wild animals, too. And when people care about animals, that can help boost interest in conservation efforts.

“Many people might talk about their ‘needy' or ‘shy’ dog, yet not consider that spiders, cows, squirrels, or other wild animals may display similar individual-level differences,” she says. “People tend to care about conserving what they can best relate to, and I think the field of animal personality is a reminder that people have many more similarities to wildlife than differences.”