Jack Dykinga / Burrowing owl (Athene cunicularia) at sunset, standing on one leg, Marana, Sonoran Desert, Arizona, USA. October.

Andy Rouse / Gentoo penguin (Pygoscelis papua) walking on beach, Saunders Island, Falkland Islands.

Luciano Candisani / Jacare Caiman (Caiman yacare) standing on bottom of wetland, Pantanal, Brazil

Andy Trowbridge / Arctic Fox (Alopex / Vulpes lagopus) standing on ridge, mist/fog in the background. Dovrefjell National Park, Norway, September.

Jussi Murtosaari / European brown bear (Ursus arctos arctos) standing on one foot, northern Finland, May.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cub peering out from behind its mother, Khutzeymateen Grizzly Bear Sanctuary, British Columbia, Canada, June.

Denis-Huot,Denis-Huot / White-backed Vulture (Gyps Africanus) feeding, Masai-Mara Game Reserve, Kenya

Laurent Geslin / Lapwing {Vanellus vanellus} standing on one leg with wing outstreched. UK.

Eric Baccega,Eric Baccega / Female Grizzly bear (Ursus arctos horribilis) standing up in alert and looking around, while feeding on sedge, Khutzeymateen Grizzly Bear Sanctuary, British Columbia, Canada, June.

Bence Mate / Portrait of Black-winged stilt immature (Himantopus himantopus) standing on one leg, and stretching, Hungary

Igor Shpilenok,Igor Shpilenok / Kamchatka Brown Bear (Ursus arctos beringianus) stands on its back legs to more easily determine the source of an unfamiliar sound. Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Fa...

Denis-Huot,Denis-Huot / Grizzly bears (Ursus arctos horribilis) looking for salmon, Brooks river, Katmai national park, Alaska, North America,