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.

Jordi Chias / Humpback whale (Megaptera novaeangliae) fluke Antarctic Peninsula, Antarctica.

Jordi Chias / Humpback whale (Megaptera novaeangliae) diving, tail fluke, Antarctic Peninsula, Antarctica.

Alex Mustard / Common seahorse (Hippocampus kuda) female wrapping her prehensile tail around piece of wood on the seabed. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Robert Valentic / Rough-scaled death adder (Acanthophis rugosus) waving tip of tail as a lure to entice prey within striking range. Mount Isa, Queensland Australia.

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub playing with mother's tail, Jao Reserve, Botswana

Suzi Eszterhas / Leopard (Panthera pardus) five-week-old cub playing with mother's tail, Jao Reserve, Botswana

David Woodfall / European beaver (Castor fiber) rear view in wetlands, in captive breeding programme .Bevis Trust, Carmarthenshire, Wales, UK, May.

Shane Gross / Pelagic thresher shark (Alopias pelagicus) cleaned by a Bluestreak cleaner wrasse (Labroides dimidiatus) at Monad Shoal off Malapascua Island, Philippines.

Shane Gross / A juvenile soldierfish, possibly a Crescent-tail bigeye (Priacanthus hamrur) in the open ocean at night off Anilao, Philippines.

Espen Bergersen / Humpback whales (Megaptera novaeangliae) showing tail fluke when they dive. Kvanangen, Troms, Norway. December

Espen Bergersen / Humpback whale (Megaptera novaeangliae) diving. In background a diving boat and 3 divers visible in the water. Kvanangen, Troms, Norway. November

Espen Bergersen / Sperm whale {Physeter macrocephalus} showint tail fluke as it dives. Photographed just before midnight. 22 nautical miles northwest of Andenes, Northern Norway. July

Espen Bergersen / Humpback whale (Megaptera novaeangliae) showing tail fluke as it dives. Kvanangen, Troms, Norway. November

Espen Bergersen / Killer whale / orca (Orcinus orca) splashing with tail fluke. Kvaloya, Troms, Norway October Sequence 4 of 7

Espen Bergersen / Humpback whale (Megaptera novaeangliae) showing tail fluke as it dives. Kvanangen, Troms, Norway. December

Tui De Roy / Marine iguana (Amblyrhynchus cristatus), Punta Vicente Roca, Isabela Island, Galapagos

Tui De Roy / Marine iguanas (Amblyrhynchus cristatus) fighting, Punta Vicente Roca, Isabela Island, Galapagos

Nick Hawkins / North Atlantic right whale (Eubalaena glacialis) tail fluke, diving to feed in the Gulf of Saint Lawrence, Canada. Endangered species. July

Espen Bergersen / Aerial shot of two Killer whales (Orcinus orca) swimming inside a shoal of Atlantic herring (Clupea harenguis), hunting, with one Killer whale tail slapping to stun the Herring, Sommaroy, Troms, Norwa...

Espen Bergersen / Aerial shot of two Killer whales (Orcinus orca) swimming inside a shoal of Atlantic herring (Clupea harenguis), hunting, Sommaroy, Troms, Norway, January.

Espen Bergersen / Aerial shot of a Humpback whale (Megaptera novaeangliae) diving and showing tail fluke, Troms, Norway, January.

Espen Bergersen / Aerial shot of a group of Killer whales (Orcinus orca) tail slapping, shot pans to the right, Skjervoy, Troms, Norway, November.

Espen Bergersen / Aerial shot of a female Humpback whale (Megaptera novaeangliae) and calf surrounded by Killer whales (Orcinus orca), mother hits sideways with her tail fluke to drive Killer whales away, Skjervoy, Tro...

Marie Read / Roseate spoonbill (Ajaia ajaja) adult in breeding plumage preening tail feathers, Black Point Wildlife Drive, Merritt Island National Wildlife Refuge, Florida, USA, January.

Cyril Ruoso / Ring-tailed Lemur (Lemur catta) basking, Anja Park, Madagascar

Cyril Ruoso / Ring-tailed Lemur (Lemur catta) basking, Anja Park, Madagascar

Cyril Ruoso / Ring-tailed Lemur (Lemur catta), Anja Park, Madagascar

Cyril Ruoso / Ring-tailed Lemur (Lemur catta) in tree, Anja Park, Madagascar

Lorraine Bennery / Black lemur (Eulemur macaco macaco) female sitting in tree. Lokobe Reserve, Nosy Be, Madagascar.

Lorraine Bennery / Blue-eyed lemur (Eulemur flavifrons) male looking down from branch. Sahamalaza, Madagascar.

Lorraine Bennery / Blue-eyed lemur (Eulemur flavifrons) female in tree. Sahamalaza, Madagascar.

Staffan Widstrand / Golden eagle (Aquila chrysaetos) in flight over snow. Kalvtrask, Vasterbotten, Lapland, Sweden. January.

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) tail slapping at sunrise, Lahaina, Maui, Hawaii

Lorraine Bennery / White-fronted brown lemur (Eulemur albifrons) in tree, Rainforests of the Atsinanana, Marojejy National Park, Madagascar. Endangered species, endemic.

Sven Zacek / Ural owl (Strix uralensis) female on nest after snowfall. Tartumaa, Southern Estonia. March.

Sven Zacek / Ural owl (Strix uralensis) female on nest in tree stump. Tartumaa, Southern Estonia. April.

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

Paul Hobson / Rufous motmot (Baryphthengus martii) perched on branch. Rancho Naturalista, Cartago, Costa Rica.

Paul Hobson / Resplendent quetzal (Pharomachrus mocinno) male perched on branch. Costa Rica.

Chase Dekker / Orca (Orcinus orca) male tail slapping, Monterey Bay, California

Sandesh Kadur / Bamboo lemur (Hapalmur griseus) sitting on tree stump. Andasibe-Mantadia National Park, Madagascar.

Hiroya Minakuchi / Southern Right Whale (Eubalaena australis) sailing at sunset, Peninsula Valdez, Argentina

Alex Mustard / Remoras (Remora sp.) hitchhiking on the tail of a large (13-15m) female whale shark (Rhincodon typus) swims in open water. Wolf Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

David Fleetham / Humpback whale (Megaptera novaeangliae), mother and calf swimming just below surface in front of the West Maui Mountains. South of Lahaina, West Maui, Hawaii.

Juergen Freund / Slow motion aerial shot of a Pygmy blue whale (Balaenoptera musculus brevicauda) blowing / breathing at the surface before diving, Banda Sea, Indonesia.

Terry Whittaker / Juvenile Red fox (Vulpes vulpes) interacting with and trying to play with an adult in an urban garden, Greater Manchester, UK, August. Filmed using a camera trap.

Claudio Contreras / Grey whale (Eschrichtius robustus) tail, San Ignacio Lagoon, El Vizcaino Biosphere Reserve, Baja California, Mexico, March

Staffan Widstrand / Wild Wonders of China / Golden pheasant (Chrysolophus pictus) male jumping, Yangxian Biosphere Reserve, Shaanxi, China

Franco Banfi / Bryde's whale (Balaenoptera edeni) tail, Trincomalee, Eastern Province, Sri Lanka, Bay of Bengal, Indian Ocean

Konrad Wothe / Booted Racket-tail (Ocreatus underwoodii) feeding on flower nectar, Ecuador

Franco Banfi / Sperm whale (Physeter macrocephalus) tail below water as whale surfaces, Dominica, Caribbean Sea, Atlantic Ocean, Vulnerable species.

Lucas Bustamante / Red tailed boa constrictor (Boa constrictor constrictor) juvenile, portrait, with tail wrapped round head, Cuayabeno, Sucumbios, Ecuador.

Ross Hoddinott / Harvest mice (Micromys minutus) on grass stems, Devon, UK. July 2016. Captive.

Ann & Steve Toon / Kori bustard (Ardeotis kori) male courtship display, Kgalagadi Transfrontier Park, Northern Cape, South Africa.

Paul Bertner / Fantastic Leaf-tail Gecko (Uroplatus phantasticus) male camouflaged amongst leaves, Ranomafana National Park, Madagascar

Paul Bertner / Blue-legged Chameleon (Calumma crypticum) curled tail, Ranomafana National Park, Madagascar

Phil Savoie / Garden bumblebee (Bombus hortorum) flying to Purple toadflax (Linaria purpurea) Monmouthshire, Wales, UK, July.

Silke Arndt / Western rattlesnake (Crotalus viridis viridis), threat display, South Dakota, USA, September.

Ingo Arndt / American Crocodile (Crocodylus acutus) swimming in open ocean, Pacific Coast, Ostional, Costa Rica

Ingo Arndt / Harvest Mouse (Micromys minutus) using tail whilst climbing in reed, Germany, captive.

Ingo Arndt / Harvest Mouse (Micromys minutus) using tail whilst climbing in reed, Germany, captive.

David Pattyn / Common brown lemur (Eulemur fulvus) jumping amongst branches, Anjajavy Private Reserve, north west Madagascar.

SCOTLAND: The Big Picture / Red Squirrel (Sciurus vulgaris) disappearing behind tree, tail visible, Cairngorms National Park, Highlands, Scotland, UK, August.

SCOTLAND: The Big Picture / Red squirrel (Sciurus vulgaris) climbing down Scots pine tree, just tail visible. Cairngorms National Park, Highlands, Scotland. August.

Chien Lee / Fantastic Leaf-tail Gecko (Uroplatus phantasticus) female mimicking wilting leaf, Ranomafana National Park, Madagascar

Chien Lee / Common Flat-tail Gecko (Uroplatus fimbriatus) on tree, Marojejy National Park, Madagascar

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.

Cyril Ruoso / Rabbit (Oryctolagus cuniculus) juvenile running away, Burgundy, France.

Tony Wu / Humpback whale (Megaptera novaeangliae) rear view, taken while the whale was staying still and singing. Hunga Channel. Vava'u, Kingdom of Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) males tail fluke, Vava'u, Tonga, Pacific Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae), fluke of female with male calf playing below, Vava'u, Tonga, Pacific Ocean.

Chien Lee / Ring-tailed Lemur (Lemur catta) mother carrying young, Berenty Private Reserve, Madagascar

Chien Lee / Ring-tailed Lemur (Lemur catta) mother carrying young, Berenty Private Reserve, Madagascar

Lou Coetzer / Pintailed whydah (Vidua macroura) male displaying to female, Masai Mara, Kenya.

Pascal Kobeh / Long-snouted seahorse (Hippocampus guttulatus) with prehensile tail twined round seagrass, Etang de Thau Lagoons, Languedoc-Roussillon, France.

Michel Poinsignon / Black headed gull (Chroicocephalus ridibundus) taking off, detail of legs and water droplets, Pusztaszer, Hungary, April

Anup Shah / Southern plains grey langur / Hanuman langurs (Semnopithecus dussumieri) rear view sitting, gathered on sandstone cliffs . Jodhpur, Rajasthan, India. March.

Anup Shah / Southern plains grey langur / Hanuman langur (Semnopithecus dussumieri) juveniles playing at sunrise, Jodhpur, Rajasthan, India. March.

Benjamin Barthelemy / Close-up of a Red fox (Vulpes vulpes) resting, with mountains in the background, Vanoise National Park, Rhone Alpes, France, October.

Wild Wonders of Europe / Widstrand / Humpback whale (Megaptera novaeangliae) tail fluke above water before diving, Senja, Troms County, Norway, Scandinavia, January. Cetaceans are attracted to this area to feed on the large numbers of sp...

Wild Wonders of Europe / Widstrand / Humpback whale (Megaptera novaeangliae) tail fluke above water before diving, Senja, Troms County, Norway, Scandinavia, January. Cetaceans are attracted to this area to feed on the large numbers of sp...

Wim van den Heever / Vervet Monkey (Chlorocebus pygerythrus) baby jumping between branches, photographed mid air. Okavango Delta Botswana.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) displaying, Jalasjarvi, Finland, April.

Claudio Contreras / Whale shark (Rhincodon typus) feeding view of tail, Isla Mujeres, Caribbean Sea, Mexico, August. Vulnerable species.

Cheryl-Samantha Owen / African elephant (Loxodonta africana) baby trying to grab the tail of adult, Amboseli National Park, Kenya.