Blizzard A Killer For Squirrels

Chicago’s Blizzard of 1999 wasn’t kind to man or beast, but squirrels especially took it on the chin, according to findings of a squirrel research project in progress at the Morton Arboretum in Lisle.
In fact, it’s possible that as many of the bushy-tailed creatures were done in by the snow in January as normally give up the ghost during an entire winter.
“Typically, about 30 to 40 percent of the squirrel population is lost over the course of a winter,” said Joel Brown, a biology professor at the University of Illinois at Chicago who has studied squirrels at the Arboretum for more than 10 years. “Because of the storm, between 25 and 40 percent of the squirrels at the arboretum were wiped out in January, and the winter isn’t over yet.”
Brown, who also studies squirrels in the more urban environs of Oak Park, said his arboretum mortality estimates generally hold true for the entire Chicago-area squirrel population.
What does the squirrel die-off mean? Fewer squirrels in the spring, Brown predicted, but the ones who survive to scamper around your back yard will be bigger and tougher. And right now, they’re in the mood for romance.
“During the recent storm, with the cold and the heavy snow, squirrels lost out twice,” Brown said. “For a squirrel, making it through the winter depends upon having a comfortable place to live and having a large cache of seeds and nuts to eat. Because of the deep snow cover, they couldn’t get to their food caches, and a fair number weakened and died. Others who went out in the aftermath of the storm were so desperate for food that they took chances and were picked off by predators, like hawks and coyotes.”
The last time the Chicago-area squirrel population was hit so hard was during the unusually frigid winter of 1993-94, when about 75 percent of the animals were wiped out over a six-week period, according to Brown.
Brown said that it is no accident that squirrels sighted now in back yards and natural areas such as the arboretum tend to be robust specimens.
“People tell me that they see these big, tough-looking squirrels after a storm,” Brown said. “That’s because the little guys have been culled out.”
articles.chicagotribune.com/1999-02-10/news/9902100116_1_squirrel-population-storm-snow