Kenneth Kieser: Wildlife is built for winter survival
My grandmother was a kindhearted soul that always worried about birds and animals when cold weather set in.
I assured her that all creatures surviving the sometimes-brutal midwestern winters were equipped better than humans for outside living, but it didn’t stop her worrying. Here are some reasons why wildlife survives long winters of cold nights and snow or ice:
• Ducks and geese are equipped to survive cold weather, including dense layers of insulating feathers called “down” by quilt, coat and vest manufacturers. This thick layer of feathers seals in body heat. Geese have the thickest down and stay around our area longer in winter.
Waterfowl bodies stay warm, but what about their bare feet and legs? Fowl have countercurrent blood flow to reduce heat loss through their feet and legs. Warm arterial blood flowing to the feet passes close to cold venous blood returning from the feet, keeping the lower extremities supplied with just enough blood to provide tissues with food and oxygen and warm enough to avoid frostbite while creating a natural foot and leg warmer.
• Bobwhite quail find new habitat every winter. They spend more time near shrub-type cover with bare ground underneath or cornfields when available and will likely stay in coveys around their chosen habitat until April. Then they split up in pairs to breed.
Sadly, well-meaning folks sometimes spread grain outside this shrub-type cover where quail hide from predators. The quail leave their cover for this much needed food and become easy prey for various predators like hawks and owls.
• Not all birds migrate. A certain group are permanent residents here like chick-a-dees, sparrows and nuthatches. We will see different species migrating back into this area as spring progresses. Geese and ducks return when open water is present.
Long-distance migrants that mainly eat insects move to the tropics. This might include warblers, fly catchers and orioles. Hummingbirds and butterflies eventually follow the same type of pattern.
Great horned owls, bluebirds, red-tailed hawks and species that build nests inside tree cavities or boxes will likely start nesting in late February and March. Some may be in open nests, braving the weather. Babies stay under their parents for warmth. But an extra layer of fat insulates younger birds, especially birds that are eating well.
• Wild turkeys fare well in the worst winter conditions by finding food while digging through snow, ice and mud with their sharp claws. Adult birds provide quite a fight against most predators with their strong wings and sharp spurs. Toms roost in bachelor groups and join the big group for daily feedings.
When the snow drifts and temperatures drop, turkeys abandon their night-time roosts on tree limbs and congregate around pine trees and soft woods – the thicker, the better.
• Deer simply move less during frigid temperatures to conserve much needed calories which can be the difference between survival and starvation. Nutritious food is scarce during the winter and the deer's metabolism actually slows down significantly to help retain energy needed to keep the body warm.
Deer dig through ice and deep snow with their hooves to find meager tidbits. They look for windbreaks around conifers in thick brush on creek banks and love southern banks where the sun offers some warmth. Overhead snow-packed tree canopies offer welcome cover.
Whitetail deer have four stomachs, so they feed heavily before a big winter storm. They gorge on food stored in one stomach. Later they will bring up balls of the vegetation and chew it for proper digestion.
• Rabbits, rodents and quail with the best cover and food sources probably made it. Many did not. They have a low survival percentage but generally a good reproductive rate.
• Fish survival depends on amounts of oxygen that filters through the ice. Snow lying for long periods on a shallow frozen pond is disastrous. Sun penetrating through the ice helps create oxygen that is badly needed for fish survival. Fish in deeper pools have a greater chance of survival.
• Does anyone worry about insects in the winter? I don’t, but they are interesting cold-weather survivors.
Grasshoppers are hatched from eggs; bet you didn’t know that. The eggs survive winter while grasshoppers perish from the cold or various diseases.
Flies make their triumphant return by hatching out of eggs the last generation left before dying. This is especially good news for those that like to be aggravated at picnics.
Spiders are cold-blooded and have a built-in antifreeze so they will not freeze to death. Many survive under big leaf piles or other cover – like barns, your attic or basement. Mothers die after laying their eggs, generally in the fall. Babies survive in their egg sacs that help keep them warm throughout the cold months so they can hatch to freak you out.
Moths survive the winter in a variety of ways. Some species eggs laid in late summer or fall do not hatch until the following spring, when there is plenty of food. Many more species spend the winter as caterpillars that remain dormant until spring.
Some insects migrate. Some butterflies and moths fly long distances. Monarch butterflies spend the summer in Canada and the Northern U.S. They migrate as far south as Mexico for the winter while other migrating insects including a variety of moths don’t fly nearly as far.
Termites and Japanese beetles move downward into the soil. Earthworms, too, move down, some as far as six feet below the ground surface.
Finally, let’s discuss everyone’s favorite bug, mosquitoes. Mosquitoes are cold-blooded and hibernate in temperatures less than 50 degrees. The adult females lay their eggs in freezing water and die. The eggs hatch in warm weather so another batch of mosquitoes can bite you when spring temperatures make us all go fishing.
• Even trees take precautions for winter. During the fall, tree sap retreats to the trunk. A limb laden with sap would easily break with the added weight of ice and snow. During spring the sap returns to feed the growth of leaves or fruit.
Truthfully, my grandmother shouldn’t have worried about our wildlife in winter, but I could never convince her.
Kenneth Kieser, a veteran outdoors writer and member of the Waterfowlers Hall of Fame and National Fresh Water Fishing Hall of Fame, writes a weekly outdoors column for The Examiner. Reach him at email@example.com.