Jim Kjelgaard 
Kalak of the Ice [EPUB ebook] 

The fascinating story of a polar bear and her search for her two cubs, this is also a story of the snowbound Arctic and of the surprising number of birds and animals that live in its inhospitable wastes.
Kalak was a polar bear whose ferocity and cunning had convinced the Eskimos that she was bewitched. But actually, Kalak, like the Eskimos themselves, was just struggling to find food for herself and her cubs, and to outwit the enemies that lay in wait for her everywhere. In this ruthless land where all species, from the tiny lemmings to the bears and whales and Eskimos, prey on each other just to stay alive, wits are almost as important as strength – a fact which adds greatly to the suspense of "Kalak of the Ice."