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

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

Gabriel Rojo / Chimango caracara (Milvago chimango) standing on one foot, La Pampa, Argentina

Krista Schlyer / Whooping crane (Grus americana) International Crane Foundation, Wisconson, USA. Captive.

Markus Varesvuo / Water rail (Rallus aquaticus) on rock, Uto, Parainen, Finland August.

Hanne & Jens Eriksen / Kentish plover (Charadrius alexandrinus) male, Oman, January.

Hanne & Jens Eriksen / Pacific golden plover (Pluvialis fulva) moulting, during migration, Oman, May.

Hanne & Jens Eriksen / Demoiselle crane (Grus virgo) resting, Oman, February.

Richard Du Toit / Pied Avocet (Recurvirostra avosetta) landing with wings spread, Marievale Bird Sanctuary, South Africa, August.

Florian Möllers / White stork (Ciconia ciconia) captive, adult standing on one leg in spring meadow, Vogelpark Marlow, Germany, May.

Edwin Giesbers / Two Grey Heron (Ardea cinerea) in snow. They stand on one leg and retract their necks to reduce heat loss. The Netherlands, January.