The blue fox is a color phase of the Arctic white fox and may occur
anywhere in the range of the typical animal. In fact, the blue phase
bears the same relationship to the white that the black phase does to
the red fox. In the Pribilof, or Fur Seal, Islands of Alaska, however,
through the influence of favorable climatic conditions, assisted by
artificial selection in weeding out white animals, the blue phase has
become the resident form. Isolation on these islands has developed
other characters also which, with the prevailing color, render the
Pribilof animal a distinct geographic race of the white species. A blue
fox is also the prevailing resident animal in Iceland.
In years when fur-seals were killed in considerable numbers on the
Pribilofs their carcasses remained on the killing grounds as a
never-failing store of food through the winter. During summer there
is an abundance of nesting water-fowl, and throughout the year there
are mice on land and the products of the sea along shore. As a result
the foxes have thrived amazingly and several hundred skins have been
produced a year. With the lessening number of seals now being killed
on the islands and the resulting scarcity of winter food, the fate of
the foxes is somewhat in doubt. The Pribilof skins are of high market
value, bringing from $40 to $150 each in the London market.
Stock from the Pribilofs has been introduced on a number of the
Aleutians and other Alaskan islands for fur-farming purposes. The value
of these fur-bearers is so great that special effort should be made not
only to keep up the stock on the islands, but still further to improve
it.
The Pribilof foxes have from five to eleven young, which are usually
born above ground and are later carried to the shelter of dens dug
in the open or under the shelter of a rock. Foxes have become so
accustomed to people on these islands that they have little fear and
come about boldly to satisfy their curiosity or to seek for food. They
often show an amusing interest in the doings of any one who invades the
more remote parts of their domain. White animals born on the islands
or coming in by chance when the pack ice touches there in winter are
killed, whenever possible, in order to hold the blue strain true.
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