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.

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.

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

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.

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

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

Melvin Grey / Violet-tailed sylph hummingbird (Aglaiocercus coelestis) hummingbird adult male, approaching flower to feed, Tandayapa, Ecuador

Thomas Marent / Sykes Monkey (Cercopithecus albogularis) and Red-tail Monkey (Cercopithecus ascanius) hybrid, Mount Kenya Wildlife Conservancy, Kenya

Alex Mustard / Scissortail sergeants (Abudefduf sexfasciatus) swimming over hard corals (Acropora sp.) on shallow reef at sunset, split level view. Gubal Island, Egypt. Red Sea.

Tony Heald / Junglefowl (Gallus gallus) male, Kaziranga National Park, Assam, India, March.

Claudio Contreras / Red-bellied Squirrel (Sciurus aureogaster) peering round branch, Mexico City, Mexico, November.

Fabrice Cahez / Red fox (Vulpes vulpes) pouncing on prey, Vosges, France, September.

Fiona Rogers / Red-tail Monkey (Cercopithecus ascanius) in tree, Kakamega Forest Reserve, Kenya

Ann & Steve Toon / Ground squirrel (Xerus inauris) Kgalagadi Transfrontier Park, Northern Cape, South Africa Non-ex.

Markus Varesvuo / Waxwings (Bombycilla garrulus) feeding on snow covered Rowan (Sorbus) berries, whilst in flight, Kuusamo, Finland, Scandinavia, January. Magic Moments book plate.

Jussi Murtosaari / Red squirrel (Sciurus vulgaris) portrait, southern Finland, October.

Jeff Rotman / Bullethead parrotfish (Chlororus sordidus) tail. Red Sea, Egypt

Fabrice Cahez / Red squirrel (Sciurus vulgaris) rear view of tail on moss covered tree, Allier, Auvergne, France, March

Andrew Parkinson / 2020VISION / An adult male Mallard (Anas platyrhynchos) comes in to land, backlit by evening sunlight, Derbyshire, England, UK, March. Did you know? In addition to the colour differences between male and female du...

Mark Hamblin / 2020VISION / Red deer (Cervus elaphus) stag in pine woodland in winter, Cairngorms National Park, Scotland, UK, February. Did you know? British red deer are different to European red deer, having a shorter tail an...

Fabrice Cahez / Red fox (Vulpes vulpes) hunting, head in hole, Vosges, France, June

Andrew Parkinson / Rear view of Red squirrel tail (Sciurus vulgaris) foraging in deep snow, Cairngorms National Park, Scotland, UK, March.

Sergey Gorshkov / Sockeye salmon (Oncorhynchus nerka) spawning, Lake Kuril, Kamchatka, Far East Russia, July

David Kjaer / Red Kite (Milvus milvus) diving towards prey whilst in flight, Wales, UK, March.

Aflo / ic-07203 Japanese red fox cub biting mother's tail (Kitsune) {Vulpes vulpes japonica} Japan

Andy Rouse / Red squirrel (Sciurus vulgaris) in snow, with some settled on tail, sitting on a branch, Scotland, UK

Andy Rouse / Red Kite (Milvus milvus) in flight, Wales, UK

Fred Bavendam / Crescent-tail Bigeye (Priacanthus hamrur) in front of a sea fan, Uepi Island, Solomon Islands

Rolf Nussbaumer / Coppery-headed Emerald, Elvira cupreiceps, male in flight feeding on Spiral Ginger (Costus Pulverulentus), Central Valley, Costa Rica, Central America, December 2006

Rolf Nussbaumer / Red-billed Streamertail {Trochilus polytmus} male feeding on Bleeding Heart Vine {Clerodendrum thomsoniae} Rocklands, Montego Bay, Jamaica.

Konrad Wothe / Brown Mouse Lemur (Microcebus rufus), Madagascar

Duncan Usher / Eurasian Red Squirrel (Sciurus vulgaris) portrait on moss and fungus-covered tree stump, Europe

Fred Bavendam / Crescent-tail Bigeye (Priacanthus hamrur), Lizard Island, Great Barrier Reef, Queensland, Australia

Alex Mustard / Clearfin lionfish (Pterois radiata) mating. The female (left) has just released a raft of eggs, which is visible between her tail and the red face of the male. Taken around dusk, during the summer in...

Matthew Maran / Close up of a Red fox (Vulpes vulpes) sleeping in an allotment, London, England, UK, April.

Oscar Dewhurst / Dusky Titi (Callicebus moloch) on tree branch in the Peruvian Amazon. Madre de Dios, Peru. March

John Shaw / Red-billed tropicbird (Phaethon aethereus) in flight. Espanola Island, Galapagos, May.

SCOTLAND: The Big Picture / Red squirrel, (Sciurus vulgaris), backlit on pine branch, Cairngorms National Park, Scotland, UK.May

Marie Read / Tufted puffin (Fratercula cirrhata), adult in breeding plumage flying in preparing to land, St. Paul, Pribilof Islands, Alaska, USA, July.

Nick Hawkins / Red-billed tropicbird (Phaethon aethereus) in flight. San Cristobal Island, Galapagos.

Nick Hawkins / Red billed tropicbird (Phaethon aethereus) in flight. San Cristobal Island, Galapagos.

Nick Hawkins / Red billed tropicbird (Phaethon aethereus) in flight over volcanic rock. San Cristobal Island, Galapagos.

David Perpinan / Sexual dimorphism in adult red-footed tortoise (Chelonoidis carbonaria). Left: male (concave plastron, long tail), right: female (flat plastron, short tail) small repro only

Suzi Eszterhas / Red-tail Monkey (Cercopithecus ascanius) in tree, Kibale National Park, Uganda

Suzi Eszterhas / Red-tail Monkey (Cercopithecus ascanius) feeding on leaves, Kibale National Park, Uganda

Tui De Roy / Red-footed booby (Sula sula), group perched on branches. Genovesa Island, Galapagos.

Tui De Roy / Red-footed booby (Sula sula) landing. Genovesa Island, Galapagos.

Ashish & Shanthi Chandola / Black drongo (Dicrurus macrocercus) perched in tree amongst red flower. Dandeli Wildlife Sanctuary, Karnataka, India.

Nick Garbutt / Red ruffed lemur (Varecia rubra), female climbing in lowland rainforest understorey. Masoala National Park, north east Madagascar.

Staffan Widstrand / Wild Wonders of China / Red-billed blue magpie (Urocissa erythrorhyncha) perched on branch, Tangjiahe National Nature Reserve,Qingchuan County, Sichuan province, China

Staffan Widstrand / Wild Wonders of China / Red-billed blue magpie (Urocissa erythrorhyncha) perched on branch, Tangjiahe National Nature Reserve,Qingchuan County, Sichuan province, China

Staffan Widstrand / Wild Wonders of China / Red-billed blue magpie (Urocissa erythroryncha) perched on a branch, Yangxian Biosphere Reserve, Shaanxi, China, April.

David Fleetham / Red liomera crab (Liomera rubra) female holding a tail full of eggs in a slate pencil sea urchin (Heterocentrotus mammillatus) at night, Hawaii.

Ernie Janes / Japanese blood grass (Imperata cylindrica) 'Rubra' in garden border.

Hermann Brehm / Scarlet Macaw (Ara macao) preening tail feather, Pantanal, Brazil

Laurie Campbell / Red squirrel (Sciurus vulgaris) adult in winter coat in deciduous woodland, Berwickshire, Scotland, March.

Phil Savoie / Red-footed plumeleteer hummingbird (Chalybura urochrysia) feeding on Heliconia flower (Heliconia latispatha) La Selva, Costa Rica.

Phil Savoie / Territorial Rufous-tailed hummingbird (Amazilia tzacatl) fighting off Red-footed plumeleteer hummingbird (Chalybura urochrysia) from heliconia, La Selva Field Station, Costa Rica.

Alex Mustard / Crescent-tail bigeye (Priacanthus hamrur) shelters next to hard coral (Porites sp.). Beacon Rock, Sha'ab Mahmood, Sinai, Egypt. Red Sea.

Nick Upton / Male Great crested newt (Triturus crustatus) displaying towards another male in a pond, with a Palmate newt (Lissotriton helveticus) swimming past, Somerset, England, UK, April. Filmed at night using...

Nick Upton / Male Great crested newt (Triturus crustatus) displaying to a female in a pond, with another female swimming past feeding on Water fleas (Daphnia pulex), Somerset, England, UK, February. Filmed at nig...

Tui De Roy / Red-billed tropicbird (Phaethon aethereus) in flight, Galapagos

Fabrice Cahez / Red squirrel (Sciurus vulgaris) tail as it runs away, Allier, Auvergne, France, July.

SCOTLAND: The Big Picture / Red squirrel (Sciurus vulgaris) tail in summer seen against bark of large pine tree. Cairngorms National Park, Scotland. August.

Thomas Marent / Red-banded Poison Frog (Dendrobates lehmanni) froglet with tadpole tail, Cauca, Colombia

Ben Cranke / Red panda (Ailurus fulgens) walking along branch of tree using its tail for balance, Singalila National Park, West Bengal, India.

Tim Laman / Red leaf monkey (Presbytis rubicunda) female feeding in Strangler fig tree (Ficus dubia) Gunung Palung National Park, Kalimantan, Borneo, Indonesia.

Georgette Douwma / Elongate surgeonfish (Acanthurus mata) at a cleaning station with Diana wrasses (Bodianus diana). Indonesia.

Mark Hamblin / Red squirrel (Sciurus vulgaris) stood on log in snow , Cairngorms National Park, Scotland, UK. December.

Alex Mustard / Crescent-tail bigeye (Priacanthus hamrur) on the drop off of Little Brother Island, Egypt. Red Sea

Mark Carwardine / Humpback whale (Megaptera novaeangliae) diving below surface showing tail fluke with Red-necked phalaropes (Phalaropus lobatus) Southeast Alaska, USA August

Tony Wu / Humpback red snapper (Lutjanus gibbus) juvenile, Kokopo, Papua New Guinea.

Tony Wu / Bicolor parrotfish (Cetoscarus bicolor) juvenile with tail fin flared open, Kokopo, Little Pigeon Island, Papua New Guinea

Edwin Giesbers / Red squirrel (Sciurus vulgaris) tail sticking up from behind autumnal woodland leaf litter, The Netherlands, October.

Alex Mustard / School of Crescent-tail bigeyes (Priacanthis hamrur) swims in front of a school of Bigeye jacks (Caranx sexfasciatus). Ulong Island, Rock Islands, Palau, Micronesia. Tropical west Pacific Ocean.

Wim van den Heever / Southern Carmine Bee-Eater (Merops nubicoides) taking off, Zambezi River, Namibia.

Paul Hobson / Red fox (Vulpes vulpes) in snow, jumping, Yellowstone, Wyoming, USA, February.

Paul Hobson / Red fox (Vulpes vulpes) in snow, Yellowstone National Park, Wyoming, USA, February.

Paul Hobson / Red-footed falcon (Falco vespertinus) preening, Hungary, May.

Thomas Marent / Red-tail Monkey (Cercopithecus ascanius), Kakamega Forest Reserve, Kenya

Alex Mustard / Scissortail sergeants (Abudefduf sexfasciatus) swimming over hard corals (Acropora sp.) on shallow reef at sunset, split level view. Gubal Island, Egypt. Red Sea.

Fabrice Cahez / Red fox (Vulpes vulpes) pouncing / hunting in a meadow, Vosges, France, May.