Impala looking over its shoulder watching for predators at Moremi National Park, Botswana

One living and one dead Blue-footed Booby bird on the Galapagos Islands, Ecuador

Laughing Thrushes hang in cages in a park, central Xian, China

Laughing Thrush hanging in a cage in a park, central Xian, China

French gendarme police officer on security duty during Normandy celebrations, France

Wild Slaty-backed Gulls (Larus schistisagus), keeping watch ontop of bird watch hut. Tyuleniy Island, Russia, Asia MORE INFO: Gulls circle the Kittywakes colony in hope that if they fly, the gulls can swoop in and grab their exposed eggs

Polar Wolves, White Wolves or Arctic Wolves (Canis lupus arctos) looking into the distance, Canada

Mackenzie Wolves, Eastern wolf, Canadian wolf (Canis lupus occidentalis) in snow, on guard

Mackenzie Wolves, Eastern wolf, Canadian wolf (Canis lupus occidentalis) in snow, on guard

Mackenzie valley wolf, Canadian timber wolf (Canis lupus occidentalis) in the snow, keeping watch

Mackenzie Wolves, Eastern wolf, Canadian wolf (Canis lupus occidentalis) in snow, on guard

Indian soldier keeping watch in front of a Buddhist prayer wheel, Leh, Northern India, India, Himalayas

Santa Claus figurines on the facade of a department store, Erlangen, Middle Franconia, Bavaria, Germany, Europe

Eurasian Lynx (Lynx lynx), adult, foraging in the snow, winter, Montana, USA

European Roe Deer (Capreolus capreolus), Sweden, Scandinavia, Europe

Eurasian Lynx (Lynx lynx), adult, foraging in the snow, winter, Montana, USA

Modern sculpture, city centre, Mulhouse, Alsace, France, Europe

Cheetah (Acinonyx jubatus), keeping watch on a dead tree, Masai Mara National Reserve, Kenya, East Africa

Male figure on the entrance gate, detail, old town hall, 1570-72, Markt 1, Schweinfurt, Lower Franconia, Bavaria, Germany, Europe

Suricate (Suricata suricatta). Also called Meerkat. Female with two young at their burrow. One young is suckling. On the lookout. Kalahari Desert, Kgalagadi Transfrontier Park, South Africa.

A male ostrich, Struthio camelus, keeping watch over his clutch of chicks as they forage. Masai Mara National Reserve, Kenya.

Suricate (Suricata suricatta). Also called Meerkat. Female with three playful young at their burrow. On the lookout. Kalahari Desert, Kgalagadi Transfrontier Park, South Africa.

Suricate (Suricata suricatta). Also called Meerkat. Female with young at their burrow. On the lookout. Kalahari Desert, Kgalagadi Transfrontier Park, South Africa.