Jim Hantakof Hillside asked a good question about squirrels that I also wondered about, so I checked in with Steve Sullivan of Project Squirrel.
Ending a longer note about some other wild things, Hantak asked:
On a side note, I feed birds which inevitably means I have squirrels, I’ve noticed in the last week or so (even before the cold snap) the squirrels virtually disappeared. Where I usually have 5 or 6 around my house, I’ve only seen 1 or 2 at the most. I know they can be a pain and that they eat a lot of bird food, I’m just curious if you’ve heard of any report of missing squirrels.
I had not heard any reports of missing squirrels, but I had wondered where the squirrels go or what they do in the kind of weather we had earlier this week.
So I emailed Sullivan, who sent this back:
Just like us, squirrels prefer to stay home from work on days with really bad weather. Unlike most squirrels in our region (which may sleep for nine months out of the year), grey and fox squirrels are active year round but they will disappear on both days that are too hot and days that are too cold. Squirrels will spend the fall frantically caching hard-shelled nuts and eating to add a fat layer that is used for both insulation and as an energy reserve. When it gets cold, squirrels can simply hunker down in a tree hollow or similar place that is isolated from the wind and rely on their dense fur, thick skin, and fluffy tail provide insulation and the fat layer for the energy to stay warm. However, if a squirrel has not been able to put on a dense fat layer in the fall and maintain it with its nut cache, it will need to forage regardless of the weather. Additionally, because good winter dens are hard to come by, many squirrels may pile into the same tree hollow. This can result in an increase parasite load, like fleas and mites. In the summer, parasite exposure can be mitigated because each squirrel can build their own leaf nest and abandon it when the parasite load gets too highs but for winter, such nests are usually too drafty and hard to maintain. As parasites increase, so does scratching and hair loss and more energy must be expended maintaining warmth and healing. As a result, squirrels may have to forage in less favorable weather. If the squirrels have not been able to cache enough hard-shelled nuts or can’t find enough high-fat seeds in bird feeders, they may be in trouble. Thus, a the twin challenges of low fat reserves and parasitism can influence a squirrel’s need to forage and hence the frequency that we see them on cold days. This can result in relatively high mortality in February and March, especially on individuals that were born during the previous year.
I think you can see why I enjoy checking in with Sullivan at any excuse I can find.
Wild of the Week, a celebration of wild scenes and doings around Chicago outdoors, runs on the Sun-Times outdoors page on Sundays, as warranted.
In the fall and winter, I mix in Buck of the Week: Unplugged, the celebration of live big bucks around Chicago outdoors, on Sundays.
There are a multitude of ways to send nominations of WOTW or BOTW: Unplugged: on Facebook (Dale Bowman), Twitter (@BowmanOutside) or email (firstname.lastname@example.org).