Dec. 11, 2006 — Squirrels hit the genetic lottery with their chubby cheeks and bushy tails. It's hard to imagine picnickers tossing peanuts and cookies at the rodents if they looked like rats.
But good looks alone don't get you through Chicago winters. Nor do they help negotiate a treacherous landscape of hungry cats, cars and metal traps.
So how do they do it? And why do they search, huddle, dart, and sometimes forget where they hid their nuts?
Joel Brown aims to find out.
"We're trying to get a glimpse of what your life is like if you are a city squirrel," said Brown, a biologist at the University of Illinois-Chicago.
He and a team of students will trap squirrels in Chicago and its suburbs this winter, taking skin samples for DNA analysis. They'll strap collars on them and watch what they do. And they'll attach threads to acorns and hazelnuts, then see where the squirrels take them and when they eat them.
While the methods aren't unlike those used to study animals in exotic lands, little attention has been paid to those in human neighborhoods. It is, after all, a lot sexier to track gorillas in Africa than a squirrel on Main Street.
"Our appreciation is least in our own backyard," said Brown, who is part of a small brethren of scientists around the country who've made it their business to figure out how squirrels go about theirs.
What they've discovered is that the critters are downright crafty.
Start with their attitude toward other squirrels' food. They want it and won't hesitate to steal it.
To ward off thieves, squirrels engage in a shell game: They go through the motions of digging and pretending to jam acorns into the ground, even smoothing out the grass to make it appear as if they're covering their hiding spot, before running off with the acorns still in their mouths.
"What possible purpose could that be for other than fake out somebody watching them bury it?" said Peter Smallwood, a University of Richmond biologist.
Squirrels figure out how to outsmart devices designed to keep them away from food — something naturalist Howard Youth learned the hard way. Squirrels broke into four types of bird feeders in his Maryland yard before he found one that they couldn't penetrate. So far.
"They will try something new and eventually, if one gets it, the other ones will notice and they will figure out a way to thwart the bird feeder," Youth said.
Brown hopes to get into his subjects' little heads. One way is by setting out hazelnuts that have been shelled alongside those that haven't.
"If they pick hazelnuts with shells it means they're looking more toward the future and not in need of food right now," he said. If they pick shelled hazelnuts, "it means they're living paycheck to paycheck."
