Animal Changes in Autumn - Preparing for Winter
Fall is Here Again
For humans, fall means back to school, it’s time to break out the warmer coats and get adjusted to the idea that it’s almost winter again. We winterize our homes, put away summer clothing and get out the winter gear, prepare our cars, and hope the weatherman is correct that it will be fairly warm for a few more days at least. Have you noticed your dog or cat is getting longer fur? Is it thicker?
Nature takes care of animals by giving them a built in weather gauge. They instinctively know when winters will be very long and cold or when a storm is coming up. If the winter is to be a long cold one, they will grow longer, thicker hair. Birds instinctively migrate to warmer climates where food will be readily available.
Trees begin to lose their leaves, to go into their winter hibernation. Bears and animals that hibernate find their winter caves and tunnels to snuggle down for the winter months. Mushrooms go into full bloom mode to spread their seed for the following year, as do the trees and flowers. With this much commotion in nature, we can detect colder months ahead as well.
Invertebrates in a Hidden World
There are many creatures that fall into the category of invertebrates, such as mollusks, myriapods, crustaceans, arachnids and the insect family. During the fall months, bees begin to hibernate inside their hives, sleeping through the winter. Wasps will all die off except for the queen wasp. She will start up the colony from scratch in the spring. Many of the insects that will become adults in the spring are in pupa form throughout the winter.
Underneath the winter-weathered leaf covering on the ground, life goes on. The damp, dark, cool environment under the leaves provides a lively habitat for the creatures of what is known as the leaf litter environment. Life underneath the leaves eat the surrounding litter to survive, or will eat each other. Slugs, snails, millipedes, woodlice and spiders maintain their daily routines while living in the hidden world on the ground.
During the fall, mammals prepare for the winter months by eating enough to put on body fat. They will become less active during this time of year, to store up more of the body fat they acquire. Normal winter months are spent in areas where food sources are less available. Squirrels can be found in their nests more often than not and eat from the acorns or nut supply they have placed in the ground for winter.
When fall rolls around, it finds many creatures heading into their homes for hibernation. It’s a way of making it through the winter for animals such as frogs, insects, bears, hedgehogs, mammals and several others.
Bats leave their summer homes and travel to spend winter months in caves or tree holes. They stay fast asleep during winter and appear again in the spring. Hedgehogs wind themselves up tightly in a ball and fall asleep in the deep mounds of leaves to take their winter nap but only after gorging themselves with fruit. To use less energy, these hibernating creatures will slow their heartbeats down to a point where it almost stops completely. This is nature’s way of allowing them to maintain their strength through the upcoming long winter months.
Frogs also hibernate deep within the mud or in holes in the ground. Once they wake in the spring, they are ready to begin breeding again, which leads them to the ponds.
Time to Choose a Mate
Deer, boar and bats are seeking mates during the autumn months. Mammals that are larger, such as deer, elk and even moose, take on a more violent attitude when seeking their mate. Rutting takes place during this time. Males will battle it out by thrusting their racks together to fight until one gives in or dies. If you run into a buck or stag, it is best to stay a good distance, as they become territorial.
Bats such as Daubenton’s and Brandt’s species will sing to the females inside of the caves. It is possible for us to hear these “love songs”; however using a bat detector allows the human ear to pick up the singing even better.
Coats for Wintery Weather Wear
Autumn presents a good time for animals in colder climates to prepare for the colder winter months by donning their winter “clothing”. From white fur to feathers, animals of various species gain longer hair, thicker coats and some even produce winter footwear.
Weasels shed off that brown fur coat to trade it in for an ermine cloak. Arctic foxes change from regular footwear to thicker fur growth around their feet to enable the protection they need in the snow. Nature replenishes species with white fur, to protect them against predators in the snowy regions of the northern landscapes. White fur serves two purposes: to camouflage them against the snow and to warm them during the colder temperatures. The white fur will have the absence of pigmentation or color, which in turn fills the cells with air. The air in the cells provides the animals with a thermal insulation in the same way a bird is provided with warmer protection by trapping air between the feather barbs.
The Ptarmigan, a plant-eating bird that thrives in the northern tundra, dons white feathers that not only hide them from their enemies,
but with the white long feathers that grow over the feet and legs and down to the toes, it gives them warmer gear to survive in the frigid temperatures. The feathers also help them walk easier on the snowy ground by covering their feet. The Ptarmigan does not have down feathers like most birds do. The feathers of these birds are grown with an “after-shaft”, or additional fluffier feather that extends from the main feather. It is thought that the after-shaft feathers probably give an extra insulation cover. If the bird is cold, it finds a bit more warmth by jumping into a snow bank. Traditionally, the Ptarmigan will burrow into the snow bank to roost as well.
Animals go through a process of molting during the autumn, to gain the thicker, lighter coloring in their fur or feathers. Later in autumn, the changes begin to take place, as the daylight hours tend to shorten, indicating the winter months are coming. Just as the shorter days in autumn signify the time to gain more feathers or fur, the spring brings a longer daylight period, and the shedding of feathers or fur to prepare for the warmer months of spring and summer. Most animals fall back to a darker coat or plumage.
The climate and latitude of the regions animals live in tend to have a great effect on which do and do not change to white coats. Studies have been conducted on the long-tailed weasel, which have shown the white winter coat may be due to other factors rather than the longer or shorter days or the climate and latitude. In northern parts of the range in which the weasel is found, they turn white in the winter. In the more central part some molt to white but others remain brown all year. The southern part of the range claims no designated changes at all; with weasels remaining the brown color they are in the summer. While this is true, if a northern weasel is removed and taken to the southern part of the range, the coat will still turn white for the winter, even if snow is absent.
Arctic Fox and Snowshoe Hare
The arctic fox is white during the winter, but grayish-brown through the warmer months. This change is due to the protective mode, where an arctic fox does not want to be seen by predators nor prey. The fox consumes smaller rodents such as lemmings and voles. It is prey to polar bears, wolverines, golden eagles and snowy owls. Foxes do adapt to the climate through changing of fur, both in color and in thickness of the coat. The arctic foxes that remain in areas without a lot of snow will stay the gray-brown color to blend with the scenery, however, those that live in snowy areas remain white through the winter and will molt into the gray-brown coloring once the snow melts in spring or summer.
The arctic fox uses its long, fluffy tail to cover its face. It has fur that grows longer around the feet in the winter and has the ability to run along smoothly through the snow and ice due to the foot fur and build. The fox boasts the name, “lagopus”, which means hare-footed. Because of the furry feet of the species, it is quite like the snowshoe hare that lives in the northern part of the region.
The snowshoe hare will change colors that correspond to the environment around it. In autumn, the white fur is partly grown in, to adjust to the patches of snow on the ground. When winter is in full bloom, the hare changes fur again and becomes all white. As spring appears and the snow begins to melt, the hare will begin to show patches of brown once again. During the summer months, the hare turns into a completely brown animal.
The Polar Bear
The polar bear remains white all year round. This is because the polar bear uses the white fur for camouflage reasons, but also for
flotation. The polar bear is at the top of the food chain in most regions, however, the camouflage is a device for sneaking up on prey. Blending allows the polar bear to capture its dinner of seals, fish, birds and other food sources.
Hair of the polar bear is hollow, which accounts for the ability to float. The fur is made up of double layers. The first layer is a softer, furry, warmer undercoat and the second layer is made up of the longer, coarser hairs. The outer coat is made up of the hollow hair. Underneath all of the hair, the polar bear has black skin. Black will hold in heat to provide a warmer, sun-catching winter wear. All of the hair and skin exists on a thick layer of fat that can reach a four-inch thickness. The fat layer provides even more insulation.
Heavy fur on a polar bear’s feet gives it the ability to stay warm and to run on the ice and snow without a lot of slippage. With feet approximately 9 inches wide and 12 or more inches in length, the feet become snowshoes, allowing good movement along the snow.
Flying South for the Winter
Birds move from summer diets to fall diets in the fall and winter. Some tend to go from eating caterpillars in the summer but change to seed diets in the winter, categorizing some as carnivores in the summer months, but switching to an herbivore title during the fall and winter. The autumn brings many young birds, however, only a few will survive the winter to breed. Many species will migrate south for the colder months, such as the swallow, cuckoos and warblers. Swans, geese, ducks and waders move from the far northern areas to the south.
Birds reduce their singing in the autumn months. They sing in the spring and summer months to find a mate and to protect their territory. Birds don’t need to do this during the autumn season. The robin is the one bird that will defend its territory year round and will continue singing through the fall and winter seasons as well.
Natural Ways to Foretell Weather
There are many tales of folklore that remain in use today to tell if the weather is going to change or not. Will it be a colder, longer winter? Will it be a milder, warmer winter? People have relied on the animal kingdom to provide them with information ahead of time, to prepare themselves for longer, colder winters or shorter milder winters as well.
Even dogs and cats can give you clues as to what type of winter may be on the way. Look at your dog or cat’s fur. Is it longer? Thicker? We have all seen the pets in our home shed during the spring to prepare their coats for a warmer climate in spring and summer, but have you ever paid attention to the thickness of the coat during autumn? Animals give us clues as to the changing environment around us, such as birds flying in certain directions for several days or weeks before the season changes. If birds are flying south, you can figure that wintry weather is on the way.
Farmers and people everywhere have relied on the behavioral changes in animals to predict what is coming. Snowy seasons that may last longer, colder weather and even more drastically, earthquakes, have been predicted by animals changing their “normal” behavior are indicators that we can watch for.
One of the most well known natural indicators of rain coming is the cow that lies in the fields. It is said that when a cow lies in the field, instead of standing in the usual way, that rain is on the way. The cow can sense moisture in the air. They lie down to ensure they have a dry place to lie when the rain is upon them.
In the United States, a holiday that falls on the second of February indicates a longer, colder winter or a shorter winter by the shadow of a groundhog. If the groundhog’s shadow is apparent at noon on this day, it means the weather will remain cold and wintry for an extended six weeks.
Squirrels are known to predict the weather by the bushiness of the tail. If squirrels around you have very bushy tails, it is an indicator of a severe winter. Little evidence supports this theory, but some claim it is a true prediction of what is to come.
Dogs and cats will become a bit more restless and their behavior is seen as more nervous before thunder and lightning storms. Colder weather brings out a thicker coat.
Humans can also predict weather changes, with aches and pains. If the weather is to be cold and damp, some have pain in arthritic spots of the body or in places where the bone has been broken in past years.
Ecosystems and Species Affected by Climate Changes
The first victims have been claimed in the animal kingdom due to the human-induced climate changes. The golden toad and the harlequin frog of Costa Rica are gone completely as a result of the global warming changes we are experiencing. More species are under threat of becoming extinct as well.
Ecosystems are under threat of disappearing or may see serious and irreversible changes. One example is the coral reefs.
Polar bears in the Canadian Hudson Bay area have lost weight and are losing their fitness due to the ice breaking up two weeks earlier than usual in the spring months. This takes away 2 weeks of crucial hunting time for these bears.
Fish that are traditionally found in Cornwall in south England have relocated to areas as far north as the Shetland Islands. As the average temperature becomes warmer, the habitat for many species will lend hand to travel further up in mountainous areas or lead to a movement toward the poles. If there are no higher ground areas to travel to or the changes are occurring too quickly for the ecosystems and species to accommodate their lifestyles, loss or extinction can and will occur.
Feeding periods for younger birds and the food source supply for these birds are affected each winter as the season shortens. In Britain, the flowering time of plants and leaf-break or autumn changes date back to 1736 in records kept. The evidence shows that longer-term trends of birds breeding earlier, spring migration arrival and later autumn departure dates have been observed in North America. Changes in migratory patterns have been seen over the years in Europe as well.
What animal changes do you notice in your area during autumn? Do squirrels have thicker tails during the fall season before a cold winter? The pets you have change as well. Can you predict a colder winter by looking at your dog’s coat?
- Image: Ma2bara, “Japanese Squirrel edited version” under public domain license
- Northern Ireland Environment Agency, Rose Valley Country Park, “Wildlife in Autumn”
- WWF Global, The Impacts of Climate Change on Nature, “Animals and Plants Under Increasing Threat”
- Clouds R Us, Weather Features, “Weather Lore”
- Image: Walk, Ansgar, “Polar Bear on Ice Flow in Wager Bay” under CC BY-SA 3.0
- E-Nature, “Dressing for Winter”
- Image: Algkalv, “Terianniaq-Qaqortaq (Arctic Fox), Photographed in Kulusuk, Greenland” under CC BY-SA 3.0
- Image: Zell, H., “Lagopus muta, Rock Ptarmigan,” under CC BY-SA 3.0
- Wyoming Wildlife, Wild Times, a Free Publication of the Wyoming Game & Fish Department, “Habitat Connection: What is Your Habitat?”
- Davies, Ella, BBC Nature UK, “Early Signs of Autumn”