No Room to Run

Hunched against the elements, ecologist Bill Fraser counts Adélie penguins. This colony dwindled from 320 breeding pairs to 54 between 1990 and 2004. Average winter temperatures here have increased nearly 9 degrees Fahrenheit over five decades, and sea ice has retreated by a fifth since the mid-1970s, depriving Adélies of an important feeding platform from which they hunt krill. "The Adélies are the canaries in the coal mine of climate change in the Antarctic," says Fraser.

Source :
environment.nationalgeographic.com