Staffan Widstrand / Steller's eider duck (Polysticta stelleri) Batsfjord village harbour with red reflections on the water, Varanger Peninsula, Norway, March.

Espen Bergersen / Male Steller's eider (Polysticta stelleri) drinking on water with reflections of nearby buildings. Batsfjord, Norway. March.

Markus Varesvuo / Steller's Eider (Polysticta stelleri) ducks, males and females, in flight. Norway, March

Markus Varesvuo,Markus Varesvuo / Flock of Steller's eiders (Polysticta stelleri) in flight, Batsfjord, Norway, March.

MIKE POTTS,Mike Potts / Stellers Eider (Polysticta stelleri) a small group in flight, near Vardo. North Norway, March.

Olga Kamenskaya / Steller's eider (Polysticta stelleri) flock flying in the upper reaches of the Lena River. Flock of ducks, Baikalo-Lensky Reserve, Siberia, Russia, September

Jen Guyton / Cat-eyed snake (Leptodeira septentrionalis) from La Selva Biological Station, Costa Rica. Controlled conditions.

Jen Guyton / Cat-eyed snake (Leptodeira septentrionalis) on branch with the eggs of a Parachuting red-eyed tree frog (Agalychnis saltator). La Selva Biological Station, Costa Rica,

Jen Guyton / Cat-eyed snake (Leptodeira septentrionalis) from La Selva Biological Station, Costa Rica. Photographed in a studio.

Markus Varesvuo / Steller's eider (Polysticta stelleri) female on water, Norway Batsfjord March

Markus Varesvuo / Steller's eider (Polysticta stelleri) male on water, Norway Batsfjord March

Markus Varesvuo / Steller's eider (Polysticta stelleri) female on water, Norway Batsfjord March