Adult Adelie penguin (Pygoscelis adeliae) pair returning from the sea to feed their chicks on Paulet Island on the Northeast side of the Antarctic Peninsula.

Adult Adelie penguin (Pygoscelis adeliae) returning from the sea to feed its chick on Paulet Island on the Northeast side of the Antarctic Peninsula.

An adult Adelie penguin (Pygoscelis adeliae) leaping into the sea to forage in the Danger Island Group in the Weddell Sea, Antarctica.

Adult Adelie penguin (Pygoscelis adeliae) returning from the sea to feed its chick on Paulet Island on the Northeast side of the Antarctic Peninsula.

A lone adult Adelie penguin (Pygoscelis adeliae) on an iceberg off Port Lockroy, Antarctica. There are an estimated 2 million breeding pairs of chinstrap penguins in the Antarctic peninsula region alone, perhaps as many as 7. 5 million breeding pairs in a

Adult gentoo penguin (Pygoscelis papua) leaping off iceberg near breeding colony on Petermann Island, Antarctica. Here on Petermann Island the gentoo penguins population is rising dramatically, at the cost of the ice-dependant Adelie penguin population.

Adult Adelie penguins (Pygoscelis adeliae) falling off of an iceberg in a snowstorm at Paulet Island in the Weddell Sea. (rr)

Adult Adelie penguins (Pygoscelis adeliae) lining up to leap off of an iceberg at Paulet Island in the Weddell Sea.

An adult leopard seal (Hydrurga leptonyx) hauled out among the ice floes at Port Arthur in the caldera of Deception Island in the South Shetland Islands near the Antarctic peninsula, southern ocean. The Lindblad expedition ship National Geographic Endeavo

Adelie penguin (Pygoscelis adeliae) leaping off an iceberg to return to the sea to feed on Devil Island near the Antarctic Peninsula.