I see red foxes around my house at all times around my house, which got me to wonder just how they survive during harsh winters.
Red foxes have several adaptations to help them survive winter. These include growing thicker fur, extra fat on their bodies, and decreasing their activity.
I wanted to find further information on how these beautiful animals survive in the long, harsh winters, and I have included some of these unique adaptations below.
During winter, red foxes are seen to grow long coats that cover them up to their footpads to aid them in keeping warm.
Unlike their pups, the adult foxes do not stay in their dens to keep warm. Instead, they curl into a ball in the open, sometimes blanketed in snow.
They keep warm by covering themselves with the fur that has already grown. The coat is usually shed off at the onset of spring weather, as it is generally warmer at this time.
Low surface area to volume ratio
Red foxes have small body parts, including their legs, necks, and ears, compared to the rest of the fox family.
This means less body surface is exposed to the atmosphere, allowing them to conserve more heat. This, in turn, helps the fox stay warm in the winter season.
Camouflaged seasonal fur
The foxes have usually covered with a very thick warm coat that aids in heat insulation.
The foxes have two color variations for the different seasons of the year. During summer, they possess a dark grey thin coat that blends well with the dark vegetation when the ice and snow are no more.
In the winter, the coat changes color to a luxurious white jacket to blend in with the frozen habitat. The skin is thicker, with more rounded hairs to insulate the heat and keep the foxes warm.
Thick fur on the tail
The red fox grows thick fur on its tail. This fur is to provide more insulation in the cold season. The fox keeps the bottom inactive when asleep or in cold seasons and wraps the bottom around the body to help insulate heat. This is unlike summer, where the base is active and generates heat. The fur also varies in winter; it’s thicker than in summer.
Thick fur on the paws
The foxes grow thick fur on their paws. The skin helps to insulate them from the snow. The hair also allows them to grip slippery surfaces when icy.
The insulation keeps the cold away from the paws, keeping the heat in the body.
Fat content is well known as a good insulator of heat beneath the skin. The body fat works the same for the foxes as the thick layer helps in insulation. This also allows the fox to conserve food storage, especially when their food supply is limited in winter.
Countercurrent heat exchange mechanism
Foxes have a mechanism that is very powerful and also found in dogs. The paws are kept at a temperature lower than the body. The lower temperature minimizes heat loss via the body part in contact with the ground surfaces.
The blood flowing back from the paws is usually heated by the blood currently flowing into the legs.
This affects not cooling the core by losing heat with parts in contact with the surface. Ducks in the feet and some other birds exhibit a similar mechanism.
Foxes use the Earth’s magnetic force to navigate. Find out more here.
Sheltering in Burrows
Red foxes dig burrows in the snow to evade the harsh temperatures. They hide inside to get extra insulation from the snow. Temperatures inside the snow hole are considerably higher than outside the recess.
During winter, red foxes are less active as this helps to insulate heat around the body. By conserving their energy, less heat is exposed to the atmosphere.
This changes in summer, when they are seen to play, to help them lose heat and be calm. However the foxes are active at dusk and dawn, but during winter, their activity is relatively the same throughout the day. This activity usually increases as the mating season approaches.
Red foxes don’t hibernate during the winter season. Instead, they use their long coats and dig tunnels in the snow to hide their pups from predators and keep them warm.
Adult foxes rarely stay in their dens in winter but instead are seen outside, keeping warm with their long coats.
Feeding habits for red foxes during winter
Red foxes have super-sharp hearing due to their ears, which are pointed outward. Every snack during the winter season is worth the struggle for red foxes. They can track a squealing mouse as far as a football length and leap after it in the snow by tracing off the footsteps they leave behind in the snow.
Their diet varies according to the season. They feed on corn, berries, apples, grasses, acorns, and cherries during summer.
In winter, they feed on small mammals such as mice, squirrels, and also rabbits. They even feed on insects to help their dietary supplements. Their surplus food is hidden in unique places called a cache for use in winter seasons as there is a limited food supply.
How the red fox survives predators in winter
Human beings are the giant predators of foxes due to their coats. However, eagles, coyotes, gray wolves, bears, and mountain lions are also red foxes’ predators.
The red foxes build small dens or burrows in grassland during summer and in the snow during winter to protect themselves and their pups from predators.
They use their excellent sense of smell and patience to catch their prey by pouncing on them. Their burrows are also considered excellent storage for their food, as food is scarce in winter.
Mating during winter
Red foxes primarily form monogamous pairs each winter. Red foxes usually have a mating season, which is generally from December to February. This is when they are most heard at night screaming. These pairs stay together as parents to raise the newborn cubs after their gestation period of 51-53 days.
The pairs also nurse the cubs and shield them from predators until they are mature. The female foxes remain in some dens known as ‘earth’ as the male foxes feed the cubs for about two weeks.
By the time it is late winter, the cubs are already grown and ready to start a family of their own. The cubs reach maturity during the tenth month and have a lifespan of 12-18 years in urban areas but only three years in the wild.
Red foxes are resourceful creatures that can cope with weather conditions in sub-tropical regions or icy tundras. They are excellent hunters, provide significant support to their cubs, and have surprising ways of keeping warm, as discussed above.
They inhabit all environments, from cliffs, high mountains, woodlands, and even icy tundras.
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.