The male King Eider (Somateria spectabilis) is a large and gorgeous seaduck from the Arctic coasts of northeast Europe, North America and Asia. | +

A school of scalloped hammerhead sharks (Sphyrna lewini) lazily swims by Darwin’s Arch, Galápagos Archipelago. | photo by Eric Cheng | +

In this photo from 1912, whalers on South Georgia, an island in the South Atlantic, stand on the beach alongside their catch: a southern right whale (Eubalaena australis). | +

The Sumatran rhinoceros (Dicerorhinus sumatrensis) has a coat of reddish-brown hair, a sort-of tropical version of the extinct woolly rhino. The Sumatran rhino is critically endangered: fewer than 300 are estimated to survive in the jungles of Sumatra, Borneo and the Malay Peninsula. | +

Imperiled Beauty | photo by Laura Cornish | +

The web-footed gecko (Palmatogecko rangei) is a denizen of the dune seas of the Namib desert. It doesn’t possess eyelids and periodically licks its eyeballs to keep them clean and moist. It comes out at night to hunt insect prey. | photo by David Montgomery | +

The lined leaf-tailed gecko (Uroplatus lineatus) is perfectly camouflaged in the bamboo forests of the island of Madagascar. | +

Fog in ancient island forests. | Kahuku, Volcanoes National Park, Hawaii | +

A flock of scarlet ibis (Eudocimus ruber) flies across a Venezuelan wetland. | +

Forest giant, Kuranda National Park, Queensland. | photo by Roy Ashton | +