Mark Brownlow / Sperm whale {Physeter macrocephalus} diving, tail fluke, Kaikoura, South Island, New Zealand

Neil Anderson / Red squirrel (Sciurus vulgaris), two curled up asleep in drey inside nest box. Nest of lichen and Pine needles. Highlands, Scotland, UK. Medium repro only.

Bernard Castelein / Silky sifaka (Propithecus candidus) in tree, Marojejy National Park, Madagascar. Critically endagered species.

Claudio Contreras / Central American spider monkey (Ateles geoffroyi) juveniles hanging by tails and playing, Calakmul Biosphere Reserve, Yucatan Peninsula, Mexico, August

Ingo Arndt / Madagascar moon moth (Argema mitrei), Captive

Espen Bergersen / Sperm whale (Physeter macrocephalus) tail fluke visible as whale dives. outside Andoya, Norway March

Claudio Contreras / American crocodile (Crocodylus acutus) rear view of animal swimming away over seagrass bed, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / American crocodile (Crocodylus acutus) rear view of animal resting in shallow water, close up of tail, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Tony Wu / Humpback whale (Megaptera novaeangliae) executing a dramatic tail slap, throwing up a cascade of water with its powerful fluke, Vava'u, Tonga, South Pacific

Tony Wu / Humpback whales (Megaptera novaeangliae) unusual scene with two adults tail-slapping together in rough seas, Vava'u, Tonga, South Pacific

Bence Mate / Western diamond-backed rattlesnake (Crotalus atrox) Texas, USA, April.

Igor Shpilenok / Red fox (Vulpes vulpes) cub biting tail of adult male, Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Far East. June.