Over the past month, temperatures have been gradually cooling down, bringing windy weather and cold temperatures that mark the approaching start of winter. The first day of winter, December 21, coincides with the winter solstice. The winter solstice is the shortest day of the year, when the Earth is tilted farthest away from the sun. Due to Earth’s tilt, less sunlight reaches the Earth’s surface, leading to declining temperatures.
We all know how humans react to colder temperatures. We like to tuck ourselves in warm houses, bundle up, and maybe sip some hot chocolate. But how do other living things handle colder temperatures? From trees, to birds, mammals, amphibians, and reptiles, living things have developed a broad range of adaptations that help them survive in winter environments.
Trees: Trees can be divided into two categories: evergreen and deciduous. In order to survive winter, the needles or leaves of evergreen trees hold less water, and have adapted a wax-like coating that minimizes freezing in the cold. This way, they are able to retain water even at freezing temperatures. Deciduous trees do not have this waxy adaptation, so in order to avoid their leaves freezing, they shed them entirely each fall. In order to survive without leaves throughout the winter, deciduous trees go dormant. They rely on sugars stored from warmer months, and slow their metabolism to conserve their energy. Evergreen trees native to New Jersey include: eastern red cedar, white spruce, and white pine. Deciduous trees native to New Jersey include: american beech, black cherry, black oak, red oak, northern white oak, sweet gum, and others.
Birds: Many birds migrate to warmer climates during the winter months, however some stick around for cold. Some common birds that may be seen in New Jersey during the winter include: dark-eyed junco, northern cardinal, and house finches, among others. In the winter, there is a significant lack of insects around compared to the warmer months. Therefore, birds primarily rely on berries and seeds as a source of food. Birds also rely heavily on fat stores for energy, as well as insulation against the cold. Other ways they stay warm is by fluffing their feathers, shivering, and seeking shelter during the night.
Mammals: Some mammals hibernate over the winter, while others use different strategies to make it through the cold. Out of New Jersey’s 48 wild animal species, only 13 of them perform some level of hibernation. Some of these hibernating mammals include woodchucks and bats (which account for 6 of the species), while chipmunks, skunks, and raccoons enter a somewhat hibernation-like state of rest, though this is not technically considered true hibernation. Woodchucks hibernate continuously, and rely entirely on fat stores, while chipmunks wake up from time to time to dig into the food stores they accumulated before winter. Skunks and raccoons live off of their fat stores, but also may awaken from time to time before going back to sleep. Mammals that do not hibernate at all include: white tailed deer, squirrels, and foxes. These mammals have adapted to store more fat in the winter, and grow thicker winter coats to keep warm. Deer will eat twigs and bark when vegetation becomes limited by cold weather, while squirrels rely on stashes of food stored during the fall. Foxes, on the other hand, have little change to their diet, and continue hunting small rodents even in the cold.
Amphibians and Reptiles: Some amphibians native to New Jersey include: Fowler’s toads, green frogs, spring peepers, bullfrogs, American toads, and gray tree frogs. During the cold winter months, amphibians enter a state of rest similar to hibernation, called brumation. Amphibians that are primarily aquatic burrow under frozen water, while those that are primarily terrestrial burrow underground for the duration of winter. Reptiles native to New Jersey include: painted turtles, spotted turtles, and garter snakes. Reptiles also use the process of brumation to conserve their energy and survive through cold winters. For reptiles and amphibians, who are cold-blooding, any level of cold temperatures can be extremely dangerous and life-threatening.
There are so many exciting things to learn about winter! I asked Lenape students what their favorite part of winter was. Here were some of their responses:
Cara Antinoff: “I like when you’re really cold and then you go inside and you get super warm and you get to drink hot chocolate.”
Sam Brown: “The holiday season, and spending time with family and friends.”
Personally, my favorite part of winter is going out to explore in the snow. I love being able to wander anywhere with no fear of getting lost, since my footprints remain to lead me back home. There is something especially enchanting about exploring a snow coated forest.
Snow is not only tons of fun, but also crucial to the environment. Snow naturally reflects sunlight, helping to regulate the Earth’s temperature. Without snow, temperatures would rise drastically and dry out the ground. Snow is also a crucial source of natural water, refilling groundwater reserves, rivers, and reservoirs with fresh water. Since snow melts slowly, it allows water to infiltrate into the ground rather than simply running off as it might with rain.
So, while some people may not be fond of winter for its chilling weather, its natural cycle is still vitally important. It is a period of rest and dormancy for much of the environment around us, and can be a time of rest for humans too. So, enjoy your winter break, and when you feel the chill of the air, allow yourself to feel connected to the world around you.
