What is the usual gestation length of an Arctic fox, in days?

The usual gestation length of an Arctic fox is about 52 days.

Arctic foxes generally mate in spring, and females give birth in early summer. A litter may be large when food is plentiful, especially after strong lemming years. The pups are born in underground dens, where they are protected from freezing weather and predators.

Both parents commonly help raise the young. The pups begin emerging from the den after several weeks and remain dependent while they learn to hunt and navigate the tundra. Their survival is closely linked to food availability, including lemmings, birds, eggs, fish, and carrion.

Arctic foxes have two main seasonal coat forms: a white winter coat and a brown or grey summer coat. Not every individual changes in exactly the same way, because colour morphs vary geographically. The species is smaller than the red fox, which can compete with it as Arctic conditions warm.