Scientist trying to unlock secrets of Chicago's resident squirrels

Sunday, December 10, 2006
A fox squirrel ate a peanut Dec. 5 in Oak Park, Ill. University of Illinois-Chicago researchers, using methods employed to track animals in exotic lands, are tracking the bushy-tailed rodents this winter hoping to get a glimpse of what the life of a city squirrel is like. (CHARLES REX ARBOGAST ~ Associated Press)

CHICAGO -- Squirrels hit the genetic lottery with their chubby cheeks and bushy tails. They're rodents, after all, and it's hard to imagine picnickers tossing peanuts and cookies their way if they looked like rats.

But good looks alone don't get you through Chicago winters. They don't help you negotiate a treacherous landscape of hungry cats, big cars and metal traps.

So how do they do it? What does all that searching, huddling, darting and -- oh, not again -- forgetting where they hid their nuts mean?

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. "And the winter time is ... crunch time for them."

To get answers, Brown and a team of students will trap squirrels in Chicago and its suburbs this winter, taking skin samples for DNA analysis. They'll strap bright collars on them and watch what they do and where they go. And they'll attach threads to acorns and hazelnuts, then see where the squirrels take them and when they eat them.

Brown 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 squirrels are fascinating and downright crafty critters.

Start with their attitude toward other squirrels' food. They want it and won't hesitate to steal it.

So, to ward off thieves, squirrels engage in their own 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.

"There are generations of squirrels telling stories about the stupid human they had going," said Smallwood, who at first was stumped that he couldn't find squirrels' buried acorns.

Brown hopes to get into his subjects' little heads in his new study. 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 the shelled hazelnuts, "it means they're living paycheck to paycheck."

Squirrels even know the difference between acorns that can be stored for a long period and those that can't. If they only have access to those that can't, "they will scrape out the tiny embryo and that kills the seed (so) it stores well," said Michael Steele, a wildlife biologist and squirrel expert at Wilkes University in Pennsylvania.

That doesn't mean squirrels don't have their shortcomings.

Yes, sometimes they forget where they buried their nuts. But Brown said their sensitive noses allow them to sniff out nuts hidden by their neighbors.

And while someone once swore to Brown that squirrels looked both ways before crossing the street, they're apparently looking for something other than cars.

Robert McCleery, who completed his dissertation at Texas A&M on urban and suburban squirrels, outfitted squirrels with radio transmitter collars and found that 80 percent of those that died did so under the tires of a car or truck.

Still, who cares about squirrel habits besides a small band of scientists?

Lots of people.

Search for "squirrels" on the Internet and Web sites like "Squirrel Lover's Club" and "Scary Squirrel World" pop up. There are sites that allow readers to comment on stories like the one from Russia about a "pack of furious squirrels" that reportedly tore a dog to pieces.

Another site, "The Campus Squirrel Listings," judges colleges by their squirrel populations. The U.S. Naval Academy and the University of California, Berkeley, are among the top schools, while squirrels might want to steer clear of Cal State-Fullerton after what is described as the particularly harsh treatment of a few squirrels near the humanities building.

None of this squirrel fascination surprises Brown.

"They are the clowns in your back yard," he said. "A circus act; Spiderman."

And they appear to enjoy us as much as we enjoy them, although, "As a general rule, (to squirrels) you are a vending machine," Brown said.

But he knows the connection for humans runs deeper.

"Wildlife in one's backyard is the most intense, most enduring experience of nature than one would ever have," he said.

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