11.The basis of their diet is lemmings, whose population is correlated with that of the Arctic foxes.
When food is abundantly available, foxes can give birth to 18 cubs per litter, while when the food is scarce, they may not breed at all.
12.They are also scavengers.
When they lack food, they feed on carrion. Arctic fox usually finds animals left by other, more dangerous predators, such as wolves or bears.
13.In extreme situations of food scarcity, they also feed on feces.
They are able to survive harsh winters and food shortages due to their exceptional energy-storing fat tissue. At the beginning of winter, the polar fox can have 3,500 kcal stored fat. An average-sized polar fox needs about 112 kcal per day to survive. Fat building begins during fall when the fox can increase its body weight by more than 50%.
14.In freezing weather, polar foxes limit their movement and curl up to minimize heat loss.
They hide their head and limbs under their body and adopt the most optimal shape, which has a reduced heat transfer surface area to an absolute minimum.
15.Polar fox fur provides the best isolation among all mammal furs. They tolerate temperatures down to – 94 Fahrenheit.
They are perfectly anatomically adapted for this. Thick and multi-layered fur provides excellent thermal insulation. Additionally, the polar foxes are the only canines with fur-covered paws. Moreover, the polar fox has a low body area to volume ratio, as evidenced by its compact body shape, short snout and legs, and short, thick ears.
16.The mating period begins in the spring.
During this time, polar foxes search for a place to start a family. Fertilization occurs in April or May. Arctic foxes are monogamous, and males and females share the care of the offspring.
17.The pregnancy of Arctic foxes lasts for 52 days.
A litter can contain up to 25 cubs, a record among all mammalian predators. Cubs leave the burrow after 3 – 4 weeks after birth, and the mother stops feeding them with milk after nine weeks.
18.Arctic fox's burrows are located on hills in unfrozen soil.
A complex of burrows can cover up to 1,000 square meters. Tunneling systems can function for decades and are inhabited by the next generation of foxes. Arctic foxes usually built tunnel's exit on the south side, which lets in more heat.
19.More important than the proximity to the food source is a solid and secure burrow for polar foxes.
They tend to choose the best shelters for their families, using even red fox's burrows on shared territories. In case of a predator threat, parents relocate their offspring into harder-to-reach parts of the tunnel system.
20.When food is abundant, polar foxes can join their families to form pack-like structures.
It helps them guard and protect their territory more effectively. In such structures, polygamy is more common.
22 facts about Arctic fox