Personality matters, even for squirrels

Humans recognize that personality goes a long way, at least for our species. But scientists have been more hesitant to attribute personality – defined as consistent behavior over time – to other animals.

A study from the University of California, Davis is the first to document the personality of golden-mantled ground squirrels, which are common in the western United States and parts of Canada. The study, published in the journal Animal behavior, found that squirrels exhibited personality for four main traits: boldness, aggressiveness, activity level and sociability.

Although the golden-mantled ground squirrel is not subject to any conservation threat, the results suggest that understanding how an animal’s personality influences the use of space is important for wildlife conservation.

“People matter”

Seeing them frolic and shake, stop and then rush, the fact that ground squirrels have personalities may not come as surprising. But the scientific field of animal personality is relatively young, as is the recognition of the ecological consequences of animal personality. For example, bolder and more aggressive squirrels may find more food or defend a larger territory, but their risky behavior can also make them vulnerable to predation or accidents.

“This is in addition to the small but growing number of studies showing that people matter,” said lead author Jaclyn Aliperti, who conducted the study while earning her doctorate. in Ecology at UC Davis. “Consideration of personality in wildlife management can be particularly important when predicting wildlife responses to new conditions, such as habitat change or destruction due to human activity. . “

Personality tests

Scientists have been studying golden mantis ground squirrels at the Rocky Mountain Biological Laboratory in Gothic, Colorado for decades. It was established as a long-term study site over 30 years ago by Aliperti advisor Dirk Van Vuren, professor in the Department of Wildlife, Fish and Conservation Biology at UC Davis .

Aliperti drew on this powerful data set for his study, while running a series of experiments over the course of three summers to observe and quantify the personality of squirrels.

She notes that while there are no Meyers-Briggs tests for animals, there are standardized approaches to quantifying animal personalities. She observed and recorded the squirrels’ responses to four tests:

• New environment: squirrels were placed in a closed box with grid lines and holes.
• Mirror: Squirrels are shown with their mirror image, which they do not recognize as theirs.
• Flight Initiative: The squirrels were approached slowly in the wild to see how long they wait before running away.
• Behavior in the trap: The squirrels were captured, unharmed, in a simple trap and their behavior was briefly observed.

The advantage of the social squirrel

Overall, the study found that the more daring squirrels had larger central areas where they focused their activity. Bold and active squirrels moved faster. Additionally, bolder, more aggressive, and more active squirrels had greater access to perches, such as rocks. Access to the perch is important because it can provide a better vantage point to see and escape predators. Interestingly, access to perch was also associated with sociability.

Golden-mantled ground squirrels are considered an asocial species. They are relatively small, which gives them few opportunities to form the closer social bonds common to large ground squirrels, which typically spend more time in family units while reaching maturity. However, the study said that “within this asocial species, individuals who tend to be relatively more social appear to have an advantage.”

In such cases, being more social could save an individual’s life. Such personality differences can influence a squirrel’s ability to survive and reproduce, which could spread to the population or community level.

Davis squirrels

UC Davis is home to many squirrels, which have become something of an honorary mascot on campus.

“UC Davis squirrels are something else,” Aliperti said.

She literally means it. They are tree squirrels and very different from the ground squirrels studied by Aliperti. Still, she says her work has changed the way she views Davis’ squirrels.

“I see them more as individuals,” Aliperti said. “I think of them as, ‘Who are you? Where are you going ? What do you do ? “Versus at the species level.”

Noticing such individuality brings a more personal angle to wildlife viewing.

“Animal personality is a hard science, but if it brings you closer to animals, maybe people will be more interested in keeping them,” Aliperti said.

In addition to Aliperti and Van Vuren, study co-authors are Brittany Davis, Nann Fangue and Anne Todgham of UC Davis.