Animals can’t get out of this cold and snow, but most find a way to get along anyway
By Dave Gathman email@example.com February 3, 2014 9:48PM
Resident bison Po-Key (left) watches two companions that are joining her at Lords Park Zoo in Elgin. February 28, 2013 | Michael Smart~Sun-Times Media ORG XMIT: CST1302281434103610
Updated: March 5, 2014 6:27AM
Fonz, a 13-year-old Labrador, and Opie, an 18-month-old pit mix, were ecstatic about the chance to get out Thursday and walk around Elgin’s near west side with their master, Nichole Mackall.
But Mackall said that wasn’t their attitude when the temperature was 40 degrees colder.
“This is our first walk in two weeks,” Mackall said. “Usually I’ll walk them for a half hour at lunchtime and at night. But when it got really cold, I’d just let them out in the yard for a few minutes at a time to do their business. And Opie, whose hair is short, would look out there and not be sure she wanted to go. I bought this little coat for her and put booties on her paws to keep them from freezing.”
At least Fonz and Opie have a human “mommy” to feed them and a warm human house to sleep in. Their position might be envied by the dozens of ducks and geese that float in a narrow stretch of 32-degree river water adjacent to the Walton Islands in Elgin, or by the half-starving white-tailed deer that have to eat bare branches instead of luscious green leaves, or the red squirrel trying to remember where he buried that last walnut.
True hibernation like what a black bear does — sleeping soundly through the whole winter, with every body function drastically slowed down while living off reserves of fat — is very rare among animals that call the Fox Valley home, according to Valerie Blaine, manager of the nature programs at the Kane County Forest Preserve District’s Creek Bend Nature Center in St. Charles.
“We have a few hibernators — the groundhog, which is another name for the woodchuck ... the 13-line ground squirrel; and various species of bats,” Blaine said. “A lot of people think other animals hibernate, but those really just go into a really sound sleep in conditions like these. Raccoons are one example. And on the coldest days you don’t see squirrels anywhere. The squirrels will just curl up and wait it out in a tree cavity, if they can find one, or in the homes they build of leaves up in the tree’s branches.
“Those squirrel leaf homes are called ‘dreys,’ by the way, and dreys are surprisingly strong. When one falls to the ground and you pick it up, it’s hard to break apart.”
Squirrels do periodically become active, of course, and that’s where their famous preparations come into play. All autumn they have been burying extra acorns, walnuts and seeds in the ground all over their territories.
But are these bushy-tailed cousins of the mouse really so brilliant they can remember where they buried each of hundreds of nuts? That’s a bit controversial.
“Squirrels use a strategy called scatter hoarding, which is to hide a small amount of food in many locations,” said Bill Graser, the wildlife biologist for the Forest Preserve District of Kane County. “They locate the stashed food using a combination of memory and sense of smell.”
Blaine said that rather than remembering exactly where each acorn was buried, the squirrel’s memory process may be more like thinking, “What places would I bury something like this?” and then searching there. “It’s probably like when a human loses her car keys and she thinks back, ‘Now where would I have set down my keys?’ They also may be able to smell the seeds underground.”
Graser notes that the scatter hoarding also turns out to be a great deal for the trees that produce the acorns and seeds, such as oaks and hickories. The squirrel never finds every seed he buried, and those that remain can sprout in the spring to start new trees, often far away from the parent tree.
Some cold-blooded animals, such as frogs and snakes, just can’t take the cold, so they dig deep into the ground and just lie there inactive all winter. They do very little, burn hardly any energy and eat nothing new, Blaine noted.
Insects handle winter in a variety of ways. Bees stay in their hives and eat honey; that’s the main reason they make honey. For yellow jackets, wasps and hornets, the past year’s colonies die off in the fall, but first they disgorge pregnant new queens who wait out the winter in some concealed spot and start new colonies in the spring.
Yet other insects either fill themselves with chemical antifreeze and hide under bark, or they die and leave eggs behind to start their species anew come spring.
And that’s where this painful, obnoxious cold may turn out to be a blessing to us two-leggers. Blaine said long, deep cold snaps tend to kill off most of the over-wintering German yellow jacket queens, so our picnics may be bothered by fewer of those stinging pests next summer. And some biologists think that many of the dreaded emerald ash borers attacking Illinois’ ash trees were killed by this January’s cold, too.
As everyone knows, many bird species also migrate to sunnier climes — usually not so much because they can’t stand the cold but because the animals they eat can’t stand the cold and so they would have nothing to dine on here. That’s especially true of birds that eat flying insects, such as swallows.
But some birds stay year-round and some — such as the bald eagles that have taken up residence along the Fox River in recent weeks — even stop off in Kane County for a winter vacation after moving either northward or southward, Blaine said.
What do the birds who stay behind eat? The bald eagles dive into open stretches of the river for fish or they eat the remains of animals that died because of the winter. Other birds of prey, such as hawks and owls, go on catching the same mice and voles and chipmunks they eat in the summer. Some birds, such as woodpeckers and chickadees, dig under the bark of trees to find insects and insect larvae.
But a majority of the land birds find tiny leftover seeds to dine on until spring.
“Although winter may seem like a barren time of year, there is a wide array of food available and you can see birds taking advantage of all of them if you watch closely,” Graser said, “The flower heads of many plants still contain seeds in the winter. If you take a walk in one of our prairies, you’ll see a diversity of birds eating seeds from black-eyed susans, purple coneflower and native sunflowers, to name a few.”
A lot of people put out bird-feeders. But there’s no need to, Blaine said.
“Feeding birds provides human enjoyment, by bringing them close where we can watch them. But birds don’t need it,” Blaine said. “Birds survived winters for millennia without anybody putting bird seed out for them.”
When the temps were below zero, ducks and geese still could be seen swimming in water so cold that it would paralyze a human being in minutes. With retention ponds, creeks and even much of the river frozen over, large numbers gathered in small stretches of surviving open water around the Fox River dams and along Elgin’s Walton Islands.
There, they could dive under water to get the things ducks eat year-round such as aquatic plants, caddis fly and dragonfly larvae, crayfish, shellfish and even the occasional fish swimming past. Canada geese usually prefer to dine on land, gorging on grass or on corn and soybeans dropped by farmers. But they may have trouble getting to these under heavy snow.
“Ducks and geese have important adaptations that allow them to swim in frigid waters that would quickly kill you or me,” Graser said. “The feathers, especially the down, provide insulation by trapping air between the layers of feathers. Waterfowl also have a specialized gland called the uropygial gland. The gland secretes an oil that the birds use while preening their feathers, which spreads the oil over their feathers and body.
“They also have special adaptations in their legs and feet that help lessen heat exchange with the cold water,” Graser said. “The arteries and veins in their legs are routed in a way that allows ‘counter-current exchange’ of heat, which keeps the foot at a lower temperature but allows enough blood flow to provide oxygen and prevent frostbite.
“You’ll often see behaviors that lessen heat loss as well, such as standing on one foot. This allows one limb to be close to the body and warm up and lessens contact with the cold water or ground.”
But that doesn’t always work. At the Fox Valley Wildlife Center, a nonprofit group based in Elburn that rescues injured animals, wildlife specialist Laura Kirk said a number of ducks and geese were brought in suffering from frostbite in their feet in January.
“Most of these had been compromised already,” Kirk said. “They had a broken leg that prevented their special circulation system from keeping both feet warm. But if we can heal the break, they usually recover.”
Kirk said she thinks the local animals most endangered by the cold waves are the opossums.
“This is about the northernmost reach of the range where opossums can live. So if the winter here is also colder than normal, they can’t take it.”
Land animals that usually eat greens, such as rabbits and deer, have to settle for harder, less luscious and less nutritious fare now.
“In the winter deer mostly eat ‘woody browse,’ or the twigs and stems of trees and shrubs,” Graser said. “They also will seek out corn and beans remaining in agricultural fields after the harvest.”
When Blaine was asked what deer eat now, she said, “Our landscaping. This year they’ll do a lot of damage because their food situation is desperate.”
“Eastern cottontail rabbits eat a wide variety of plants,” Graser said. “In the winter, rabbits eat the bark, buds and twigs of woody vegetation. They are also known to eat their own droppings to recover additional nutrients.”
“Rabbits don’t construct their own burrows, but do use burrows constructed by other animals,” Graser said. “Rabbits often take shelter under brush piles, and in dense patches of vegetation.”
Even further down the size scale, mice and voles might have more trouble finding food, but get one big advantage compared to summer. They carve tunnels under the snow, whose roofs help keep owls and hawks and coyotes from finding them.
“There’s a lot of activity going on under that snow — whole networks of rodent highways,” Blaine said.