excavate large dens which may be used repeatedly by multiple generations.
This continuous reuse of dens is thought in some cases to span over several
centuries, but such long term instances are likely rare.
The Arctic fox occurs in large numbers
over a wide geographical area, and is not considered threatened over most
of its range. However, one subspecies, A. lagopus semenovi,
is close to extinction due to excessive trapping in past times, along with
introduced diseases such as mange. The subspecies occurs only on
the island of Mednij, off the northeastern coast of the former Soviet Union.
Surveys indicate that over 100 still live on the island,
and hopefully the population will increase.