Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) pair after trading incubation duties on pebble nest. Penguin on left is now free to go feed, South Georgia. Sequence 10 of 10.

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) placing gift pebble on nest before trading incubation duties with mate, South Georgia. Sequence 7 of 10.

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) pair showing courtship behavior before swapping incubation duties at nest, South Georgia. Sequence 2 of 10

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) pair engaging in courtship ritual before trading incubation duties at nest, South Georgia. Sequence 5 of 10.

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) pair engaging in courtship ritual before trading incubation duties at nest, South Georgia. Sequence 1 of 10

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) pair courting, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) nesting colony, Brown Bluff, Antarctic Peninsula, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) group, Paulet Island, Antarctic Peninsula, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) picking rock for nest, Weddell Sea, Antarctic Peninsula, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) picking rock for nest, Weddell Sea, Antarctic Peninsula, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) nesting colony, Weddell Sea, Antarctic Peninsula, Antarctica

Hiroya Minakuchi / Adelie Penguin (Pygoscelis adeliae) and Gentoo Penguin (Pygoscelis papua), Weddell Sea, Antarctic Peninsula, Antarctica