A Manitoba Conservation official has found evidence that wolves near Hudson Bay have learned to hunt polar bear cubs.

Wildlife officials havent tracked down a polar bear that was apparently injured by a tight radio collar after it was photographed in northern Alaska in early October. The bear's condition has renewed debate over use of the tracking devices.

A photo of a polar bear with bloody wounds from a too-tight radio collar illustrates an unfortunate but rare side effect of wildlife research, biologists say.