Weather Updates

Seeing fewer squirrels? It’s the weather

A squirrel spreads out shade Friday July 10 2009 Oakdale Park SalinKan. The temperature Salinwas mid 90's by early afternoon.

A squirrel spreads out in the shade on Friday, July 10, 2009, at Oakdale Park in Salina, Kan. The temperature in Salina was in the mid 90's by the early afternoon. (AP Photo/Tom Dorsey, Salina Journal)

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Updated: August 26, 2012 6:06AM

This time of year, Brian Nigbor usually has to spend some time cleaning up the mess of leaves and branches left by the squirrels that nest in a big maple tree in front of his North Side home. But not this year.

“You just don’t see them around much,” says Nigbor, 54. “It’s nothing like normal. Where did all the squirrels go? It’s so weird.”

The mild winter followed by this summer’s drought and unusual heat are probably to blame, according to Steve Sullivan, senior curator of urban ecology at the Peggy Notebaert Nature Museum in Lincoln Park.

Normally, a large number of squirrels die over the winter either from cold or starvation, but more survived last winter, says Sullivan, who is the lead investigator for Project Squirrel, a nationwide squirrel study. As a result, the young litters are facing competition with older and stronger squirrels.

“I suspect what has happened is that all of the spring babies died, and a good number of last year’s squirrels have died,” Sullivan says. “We had a weird winter that is going to influence our summer numbers, and then we had a summer drought that is going to influence the next three generations of squirrels.”

The unusual heat that’s been baking Chicago also might have hurt squirrels, which are especially sensitive to warm weather and are prone to overheating, says Joel Brown, a professor of biological sciences at the University of Illinois at Chicago.

“The extreme heat can cause stress for an animal that is daytime active,” says Brown. “They actually can get dehydrated, and, under these circumstances, may actually have some difficulty finding standing water.”

Sullivan says squirrels might be less visible, too, because they are lying low, staying in the shade to try to keep cool.

He’s asking people to record their observations of squirrels, or of a lack of squirrels, online at .

“They can observe at a very fine scale, say, their back yard, in a way that we simple can’t,” he says.

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