Mills College Biology Professor Coauthors Research on the Social Personalities of California Ground Squirrels

Oakland, CA—July 2, 2018

california ground squirrelMills College Professor of Biology Jennifer E. Smith, a team of five undergraduate students, and collaborator and coauthor Andy Sih at the University of California Davis recently examined the effects of architecture and personality on the social behavior of ground squirrels.

The team’s findings were published today in Philosophical Transactions of the Royal Society B. The peer-reviewed science journal publishes high quality theme issues on topics of current importance and general interest within the life sciences.

The study, titled Split between two worlds: automated sensing reveals links between above- and belowground social networks in a free-living mammal provides some important revelations about the ways that architecture shapes collective behavior.

Most people split their time between two or more major environments – living with family or friends within confined housing conditions, and interacting with others outside of the home in a relatively open and free manner. Like humans, many other mammals split their time between two worlds.

Using an automated detection system, Smith and her team observed California ground squirrels aboveground where space is relatively open, and belowground within a relatively constrained burrow architecture. This allowed them to examine the effects of architecture and personality on the social behavior of squirrels, uncovering their secret, belowground social lives.

Analysis by the science team found that these wild animals seek shelter in defined burrow systems but also interact with group-mates above ground. The study further revealed that belowground social structure predicts collective behaviours above ground, and that adults and juveniles associate most often. Females are key in connecting networks belowground.

More importantly, highly connected individuals belowground were also highly connected aboveground. These patterns were consistent across years.

“Basically, our study shows that socially-connected squirrels are consistently social in multiple situations,” says Professor Smith.

This is important because superspreaders may be key in determining whether diseases become epidemics. “Although the animals in this study are remarkably healthy, the parasites of California grounds squirrels may carry diseases, including plague.”

This research has potential implications for disease and information transmission for other social animals, including humans, who vary in their social network connections.

“Our findings that squirrels have consistent social personalities across major situations and time is really exciting,” Smith adds. “Key, highly social individuals likely may act as hot spots for transmission.”

The project was sponsored by the National Science Foundation, the Barrett Foundation and Contra Costa County Fish and Wildlife Propagation Fund.

About Mills College
Located in Oakland, California, in the heart of the San Francisco Bay Area, Mills College is a nationally renowned independent liberal arts college for women with graduate programs for women and men. Ranked one of the top-tier regional universities in the West by U.S. News & World Report, Mills is also recognized as one of The Best 382 Colleges in the nation by The Princeton Review. Since 1852, we’ve been empowering students to become creative, independent thinkers who take and inspire action. For more information, visit