UChicago Creatures

Nuts for squirrels

Although the University does nothing to maintain the robust squirrel population, UChicago is a pretty sweet place to be a squirrel.

Rhonda L. Smith

On campus Sciurus carolinensis residents have 4,511 trees to choose from. And with the constant flow of students, faculty, and staff across the quad, there is ample opportunity to locate provisions beyond what is offered by the local flora.

Life’s even better for those who have found their way to the Zoology Building. On the third-floor windowsill of evolutionary biologist Jerry Coyne’s lab, there is a squirrel buffet of sorts.

Coyne, professor emeritus in the Department of Ecology and Evolution and the College, started feeding the squirrels about five years ago, when he noticed them running along the windows. “I decided I’d put a little food out. Well, you know, things got out of hand. I’m taking care of a whole lot of them.”

But it’s more than a pastime to break up the day with a dose of cute. “There’s a lot of biology you can learn from watching these things close up,” Coyne says. Squirrels have hands “like little witch claws” that are perfect for gripping and “long, almost prehensile toes and long toenails” to scurry up and down trees.

He’s seen generations of squirrels (the gray squirrel has two broods a year) learn to open walnuts and improve their sunflower seed consumption rate as they mature. On his website, Why Evolution Is True, he writes about one squirrel pup (he calls it a “n00b,” or newbie) taking 30 seconds to eat a seed. Adult squirrels are about 10 times faster.

Although many people feed squirrels peanuts, Coyne has noticed their tastes lean toward “the more exotic and expensive nuts,” with pecans and walnuts hands-down favorites. When he puts out a walnut, he can “almost see their eyes light up when they see it. They instantly grab it and run off.”


Evolutionary biologist Jerry Coyne tempts a campus squirrel with a walnut. (All photos courtesy Jerry Coyne)