With temperatures plummeting below zero, we seem to see fewer squirrels and birds out and about. So, we wanted to find out how wildlife copes with the cold.
Don Quintenz has been observing nature for decades at Schlitz Audubon Nature Center, north of downtown Milwaukee. He's director of conservation.
Quintenz is confident that wildlife does feel the cold. "...Animals can sense the 'uncomfortableness' of really bitter cold," he says.
But, like humans, animals adjust.
"Animals and plants and humans go through a physiological change if you expose yourself to cold. Your body, if you're out enough, will acclimate to the conditions," Quintenz says.
He says unless the creature is a hibernator, animals work with the weather conditions. Some even thrive in the winter.
Take the meadow vole (or mouse).
"Because they live subnivean, or under the snow, this is actually a time of protection - shelter and food, all being available," Quintenz says. "They breed in the middle of winter because they have everything they need."
Here are some of Quintenz's observations:
"They work with the rhythms of the weather," he says. "They'll go into a less active period when it's really cold. But they balance that with their hunger - what's the discomfort of going out in the cold compared to hunger."
Weasels turn completely white during the winter, giving them an extra advantage.
"They have an advantage over animals that aren't white," Quintenz says. "Weasels can get closer to their prey and can more easily escape their predators."
“They’re preyed upon by gray-horned owls and coyotes - so that’s their stress in winter. But as far as warmth and food, they’re in pretty good shape," he says.
"They don’t hibernate, they hole up in trees. Young ones have to come out because they don’t have enough body fat, so they walk in the winter snows every day looking for food," Quintenz says. "The big ones can hold up for many, many weeks."
"They can actually go two months without feeding," he says. "But if you scare them off during a severe winter after two months of not feeding - and there's not good food and it's still bitterly cold - you can make the difference between survival and not surviving."
"They roost in the trees at night, and they’re on the edge of exposure," Quintenz says. "And if you flush them out of that roost on a really cold night that can actually kills them."
Quintenz has been tracking all the seasons at Schlitz Audubon. He fills notebook upon notebook with details about when birds migrate and trees flower. Over time he has observed changing patterns. He's not the only phenologist noting shifts.
"And those are important pieces of information that we can piece together when we go back to that same location and look for those same organisms," he says. "Over the course of many decades we can see change. Climatologists certainly validate it – just how spring plays out and how prolonged the winter is, how many days below freezing...."
He says erratic weather swings over time could threaten the interdependent web of nature. But, Quintenz is not an alarmist; he concentrates on sharing his passion for stewardship.
"Indigenous people really knew the value of nature because they depended on it. Progress has brought us good things materially, but somewhere in the dust, we’ve lost something. So we have to catch up and balance that. So this is the process; the stresses we’re feeling are getting us ready for change," Quintenz says.