Polar bears captured on collar cams

High-tech tracking collars on nine female polar bears have measured the animals' efforts to find food on the diminishing Arctic ice.

In Spring of 2014, 2015, and 2016, Anthony Pagano, a researcher at the University of California Santa Cruz and his colleagues, set out to track the polar bears' hunting and survival during this critical season.

The results give a polar bear's-eye view of the Arctic, and an increasing struggle.