Story and photos by Joan Herrmann
Whereiwander… Preparations for the “long winter’s nap” have begun for many already. Black bears (Ursus americanus) have “bulked up” and their stored fat will be burned for energy so there will be little loss of muscle. They may hibernate for as long as seven months. During this time they will not eat, drink, urinate or defecate. Their metabolism decreases by fifty percent and their heart rate and breathing are drastically reduced. Their dense fur provides immense warmth and their body temperatures only drop a few degrees, even during extreme cold. The female will generally begin her hibernation in late October. She may den up with this past year’s cubs if she has some as they will stay with the mother for about eighteen months. If she doesn’t have cubs but has mated in the spring she will den up alone and her cubs will be born while she is in hibernation. The males generally begin their hibernation in late November or early December. A bear den is seldom a cave but may be only a protected area where they will remain undisturbed. The den may consist of a pile of brush, an uprooted tree, or a hollow tree. The bedding can be as simple as leaves, grasses, and twigs.
Another hibernator that may be found in our area is the groundhog or woodchuck (Marmota monax). They dig extensive tunnels that may even be shared by other mammals such as skunks and opossums. After bulking up and adding as much as an inch of body fat, the woodchuck will be ready in late fall, once the temperature drop below fifty degrees, to sleep the winter away. Like black bears, they will have significant metabolic changes with their heart rate dropping from one hundred beats a minute to a mere fifteen beats per minute. Their body temperature also drops from ninety-six degrees Fahrenheit to about forty-seven degrees Fahrenheit. While living off its own body fat throughout the winter the woodchuck will emerge in the spring weighing twenty to forty percent less than when it entered hibernation.
Smaller mammals have been preparing for winter throughout the spring and summer. Many of the numerous Eastern Chipmunks (Tamias striatus), which reside on our property, have been caching unsalted peanuts and black-oiled sunflowers seeds. Their nap is not constant through the winter instead they experience several cycles of semi torpidity (inactivity). Their body temperature and breathing is significantly reduced until they resume a state of activity. When they become active they will eat and eliminate waste, but they do not leave their burrows. Each burrow is segmented into different chambers and each has a different purpose that may include nesting, resting, and toileting in addition to the food caches. Burrows may be three feet below the ground and have tunnels that could be as long as thirty feet in length. Chipmunks are omnivores and their food caches, in addition to unsalted peanuts and sunflower seeds may include beechnuts, corn kernels, nuts, berries, mushrooms, beetles, grasshoppers, mice, newts, frogs, and garden bulbs. If we experience a mild spell in late winter or early spring chipmunks may be seen foraging for food to replenish their food supply.
Dormancy for the cold-blooded critter is call brumation, and it is how reptiles (snakes, turtles, and lizards) and amphibians (salamanders, frogs, and toads) survive our long cold winters. Both hibernation and brumation are stimulated by a lack of heat and decreased hours of daylight. Green frogs, bullfrogs, and leopard frogs have the ability to dig into the mud of ponds and streams and brumate until temperature as well as longer daylight hours increase. The wood frog (Rana sylvatica), the spring peeper (Pseudacris crucifer), and the gray tree frog (Hyla Versicolor) all have a similar way of brumating which is quite different from other amphibians. Instead of burying themselves in the mud of a pond or stream, they simply freeze solid. They find a suitable spot which may be a shallow depression on the woodland floor or under a fallen log, which will soon be covered with fallen leaves and snow, to spend the winter. When the temperatures drop to below freezing their eyes will become cloudy and their organs will no longer receive oxygen or nutrients as their body begins to freeze solid. Their bodies produce great quantities of glucose, from the carbohydrates stored in their liver (glycogen), which acts as a biological antifreeze. The fluids outside and between the frog’s body cells freeze, but the fluids within their body cells do not freeze. They will remain frozen until warmer temperatures thaw them out in the spring.
Another reptile that will spend the winter in a form of brumation is the painted turtle (Chrysemys picta) and like other reptiles, they are ectotherms (cold-blooded). This means that they rely on an external source for body heat, while we as endotherms (warm-blooded) need fuel (food) to maintain a constant body temperature. Turtles have lungs, not gills and yet they can remain snug in the mud on the bottom of a pond or watery habitat throughout the winter. Under the ice, in a pond, the water temperature is fairly stable throughout the winter and the turtle will, while remaining still, have a somewhat stable body temperature. There are several difficulties to overcome however, the turtle will not be able to surface because of the ice covering the pond, to take a breath and little oxygen can get into the water. In addition, there are probably many other critters in the pond that also depend on the aquatic plants which produce oxygen. The painted turtle has the ability to actually change its metabolism to a state that requires very little oxygen. Researchers have done experiments in their labs and have found that a painted turtle can go as long as one hundred days in this changed metabolic state. The change in the metabolic rate for a lengthy duration will eventually cause an acid buildup in the turtle’s tissues and cause its death. However, painted turtles are able to absorb calcium from their own shell to neutralize the acid. It is similar to a human having heartburn and taking an antacid.
Whether hibernation, torpidity, brumation, or diapause our wild critter all have amazing ways of surviving our long winters. Perhaps I will see you out snowshoeing or cross-country skiing, one of our ways of surviving our long winters.
As a Professional Nature Photographer, Naturalist, and Outdoor Educator, Joan Herrmann has been teaching and doing programs for Schools, Garden Clubs, Libraries, and Nature Centers, about 38 years. After moving from the Rochester area in 1995 she began her Photography business, Essence of Nature, and also became a co-owner of The Artworks in Old Forge, New York. As a docent at Munson, Williams, Proctor Arts Institute, in Utica, New York she has been educating children and adults, for nineteen years.
In 2007 she began working with the Black River Outdoor Educational Program (BROEP) and in 2013 and 2014 did a week-long summer program at BROEP in conjunction with Mohawk Valley Community College (MVCC). Using her love of both nature and photography she created a Flora/Fauna outdoor educational program teaching students (ages 6 to 14) the joys of nature and creative photography skills.
Joan’s love of nature has been a lifelong study of Birds, Wildflowers, Mosses, Ferns, Trees, Amphibians, Reptiles, Grasses, Insects, Spiders, Tracks, Scat, and Galls. She has assisted in the cataloging of all trails used by the hiking Coaches and photographed and identified seasonal Flora.
Since October 2016 she has been writing a bimonthly nature column with Adirondack Express Newspaper. In October of 2019, she began a bi-monthly column with My Little Falls Newspaper. You may reach her at firstname.lastname@example.org