Arctic Fox
Diet
Arctic
foxes live primarily on lemmings and voles.
In winter, the lemmings must first be located in their tunnels under the
snow. Most hunting is done in
darkness, so the fox relies heavily on its acute sense of smell and hearing to
detect its prey. It quietly traces
the lemmings' movements under the snow and then pounces and digs rapidly down to
the tunnel or nest. In summer,
lemmings are caught mainly when they are scurrying across the tundra. The fox employs stalking manoeuvres and then dashes for its
prey.
Winter
in the Far North is harsh and limited food resources can have a profound effect
on arctic fox numbers. Brown and
collared lemmings undergo population peaks every three to five years followed by
crashes caused by overcrowding and other factors, such as insufficient snow
insulation in winter. The arctic
fox population closely follows the rise and fall of the lemming population.
After a crash in the lemming population, the number of surviving fox pups
declines drastically in the fall. Large
numbers of foxes starve the following winter and many do not breed the next
spring.
In
addition to lemmings, the winter food of arctic foxes consists of arctic hares,
ptarmigan and carrion. They will
trail wolves to obtain scraps from abandoned carcasses, and follow polar bears
across frozen seas to scavenge from leftover seals.
They may also kill ringed seal pups in their birth dens.
In areas of human development, arctic foxes may scrounge food handouts or
garbage.
During
the summer, arctic foxes supplement their lemming diet with ground squirrels,
hares, eggs, and fish. They also
feed on flightless geese and waterfowl and clamber about seabird colonies
stealing eggs and pulling young from the nest.
During times of plenty, foxes will cache food for periods of want.
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