Danny Green / Hazel Dormouse (Muscardinus avellanarius) hibernating amongst leaves and acorns. Captive. Leicestershire, UK, October.

Danny Green / Polar bear (Ursus maritimus) female resting with cubs on glacier. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) and cubs resting on sea ice. Svalbard, Norway, July.

Danny Green / Polar bear (Ursus maritimus) resting in snow. Svalbard, Norway, July.

Danny Green / Reindeer (Rangifer tarandus) hunkering down in snow during blizzard. Svalbard, Norway, April.

Danny Green / Polar bear (Ursus maritimus) sleeping in snow. Churchill, Manitoba, Canada, November.

Danny Green / Ringed seal (Pusa hispida) resting on ice, reflected in water. Svalbard, Norway. July.

Nick Garbutt / King penguin (Aptenodytes patagonicus), two sleeping on snow. Grytviken, South Georgia. March.

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.

Alex Mustard / Green turtle (Chelonia mydas) resting on sea floor and two juvenile Golden trevally (Gnathanodon speciosus). Marsa El Shouna, Marsa Alam, Egypt.

Clay Bolt / Blue-banded bee (Amegilla sp) males sleeping on stem. Halmahera, North Maluku, Indonesia.

Bernard Castelein / Coquerel's sifaka (Propithecus coquereli) in tree, relaxing, Ankarafantsika National Park, Madagascar

Jordi Chias / Crabeater seals (Lobodon carcinophaga) resting on ice floating ice sheet, 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.

Suzi Eszterhas / Leopard (Panthera pardus) four-month-old cub in tree, Jao Reserve, Botswana

John Chan / Anna's Hummingbird (Calypte anna) chick, sleeping in nest, Southern California, USA, March.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) pup on a breeding beach, Orkney, Scotland, UK, April.

SCOTLAND: The Big Picture / Grey seal (Halichoerus grypus) huge group hauled out on a beach, Island of Mingulay, west coast of Scotland. May.

Ross Hoddinott / Chalkhill blue butterfly (Polyommatus coridon) Hatch Hill, Somerset, UK. August.

Matthew Maran / Red fox (Vulpes Vulpes) resting curled up close up, North London, England UK

Eric Baccega / Chimpanzee female (Pan troglodytes schweinfurthii) sleeping in a nest built in a tree, Kibale National Park, Uganda, January.

Eric Baccega / Chimpanzee male (Pan troglodytes schweinfurthii) sleeping on the forest floor with feet up, Kibale National Park, Uganda. January.

Pedro Narra / Mountain Gorilla (Goriila beringei) resting, Volcanoes National Park, Virunga Mountains, Rwanda.

Sven Zacek / Bearded seal (Erignathus barbatus) sunbathing on iceberg broken off from glacier. Kongsfjorden fjord, Spitsbergen, Norway. June 2014.

Karine Aigner / Bengal tiger (Panthera tigris tigris) head, close up. Ranthambore National Park, Rajasthan, India.

Danny Green / Sea otter (Enhydra lutris) resting on sea ice, Alaska, USA, June

Danny Green / Sea otter (Enhydra lutris) resting amongst sea ice, Alaska, USA, June

Danny Green / Sea otters (Enhydra lutris) resting on ice, Alaska, USA, June

Nick Hawkins / Galapagos sea lion (Zalophus wollebaeki), three resting underneath school bus. Isabela Island, Galapagos. 2017.

Christophe Courteau / Mountain gorilla (Gorilla beringei beringei) silverback sitting on boundary wall between Volcanoes National Park and a Potato crop, looking into valley. Area to be restored to forest. Rwanda.

Andy Rouse / Jaguars (Panthera onca) on riverbank , Pantanal, Brazil

Andy Rouse / Jaguar (Panthera onca) resting against tree on riverbank, Pantanal, Brazil

Andy Rouse / Jaguar (Panthera onca) on riverbank , Pantanal, Brazil

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

Phil Savoie / White tent making bat (Ectophylla alba) roosting in Heleconia leaf, La Selva Field Station, Costa Rica.

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) group resting in pool, Alcedo Volcano, Isabela Island, Galapagos

Tui De Roy / Alcedo giant tortoise (Chelonoidis vandenburghi) group resting in water at night, Alcedo Volcano, Isabela Island, Galapagos

Philippe Clement / Pair of Roe deer (Capreolus capreolus) resting and grazing in forest in summer, France, September.

Philippe Clement / Northern gannets (Morus bassanus) sitting on nests made with plastic, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, May.

David Fleetham / Whitetip reef shark (Triaenodon obesus) resting on sea floor. Kauai, Hawaii.

Luke Massey / Giant otter (Pteronura brasiliensis) resting on a fallen tree in the Rio Cuiaba, Brazil

Guy Edwardes / African elephant (Loxodonta africana) with Egret (Ardeidae sp) on back wtih tourists watching from boat in background. Chobe River, Botswana. 2017.

Mary McDonald / Mountain gorilla (Gorilla beringei beringei) female with baby age, 4 months, Volcanoes National Park, Rwanda

Lucas Bustamante / Four Galapagos sea lions (Zalophus wollebaeki) sleeping on beach, Floreana Island, Galapagos, Endangered species.

Lucas Bustamante / African lion (Panthera leo) resting, Etosha National Park, Harare Province, Namibia.

Theo Bosboom / Banded demoiselle (Calopteryx splendens) at sunrise, resting in the Common nettle, Roosendaal, the Netherlands. July.

Theo Bosboom / Common bluetail damselfly (Ischnura elegans) on leaf, Millingerwaard, the Netherlands, June.

Theo Bosboom / Banded demoiselles (Calopteryx splendens) pair still clasped together after mating, with two males resting nearby, the Netherlands, July.

Theo Bosboom / Common blue damselflies (Enallagma cyathigerum) group reflected in water, flying and perching on reeds - they sit on stems and fly around the water, looking for prey and females to mate. The stems ar...

Luke Massey / Wild boar (Sus scrofa) piglets resting, with mother nearby, Forest of Dean, Gloucestershire, England, UK, May.

Claudio Contreras / Caribbean Flamingo (Phoenicopterus ruber) sleeping in the breeding colony, brooding egg, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico, June, Finalist in the Portfolio Category of the Terr...

Tui De Roy / Brown pelican (Pelecanus occidentalis) close up whilst resting, Punta Suarez, Espanola Island, Galapagos

Ross Hoddinott / Broad bodied chaser dragonfly (Libellula depressa), newly emerged, resting on reeds,Broxwater, Cornwall, UK. April 2017.

Ross Hoddinott / Silver-studded blue butterflies (Plebejus argus) resting on grass and backlit by the sun, Upton Towans, Cornwall, UK. June 2017.

Ross Hoddinott / Emerald damselfly (Lestes sponsa), female resting, Broxwater, Cornwall, UK. August

Ross Hoddinott / Common blue butterflies (Polyommatus icarus) resting on grasses, Vealand Farm, Devon, UK. June 2017

Claudio Contreras / Black-browed Albatross (Thalassarche melanophris) close up resting, West Point Island, Falkland Islands, October

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, with another piglet joining, Germany, January. Captive.

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, with another piglet joining, Germany, January. Captive.

Edwin Giesbers / Close-up of a litter of Wild boar (Sus scrofa) piglets sleeping on top of their mother, Germany, January. Captive.

Fred Olivier / Northern sea otter (Enhydra lutris kenyoni) sleeping at dusk, Kachemak Bay, Alaska, USA.

Fred Olivier / Northern sea otter (Enhydra lutris kenyoni) sleeping, floating on the surface, Kachemak Bay, Alaska, USA.

Peter Bassett / King penguins (Aptenodytes patagonicus) preening in breeding colony, with mountains in the background, Salisbury Plain, South Georgia.

Steve Downer / Grove snail / brown lipped snail (Cepaea nemoralis) with juvenile riding on its back, Birmingham UK June.

Ingo Arndt / Double-crested cormorant (Phalacrocorax auritus) adult resting, close up portrait, Everglades National Park, Florida, USA. January. Finalist in the Birds Category of the GDT Awards 2015.

Roy Mangersnes / Juvenile female Polar bear (Ursus maritimus) lying down protecting a seal carcass at sunset, Svalbard, Norway, March.

Steve Downer / Close up of a Canada goose gosling (Branta canadensis) sleeping, with other goslings in the background, Birmingham, England, UK, June.

Steve Downer / Close up of Mute swan cygnets (Cygnus olor) riding on their mother's back, Birmingham, England, UK, May.

SCOTLAND: The Big Picture / Mountain hare (Lepus timidus) resting in a snowhole, with windblown snow, Cairngorms National Park, Scotland, UK, January.

SCOTLAND: The Big Picture / Grey seals (Halochoerus grypus) hauled out along the banks of the Ythan Estuary, agiatated, Aberdeenshire, Scotland, UK, February.

SCOTLAND: The Big Picture / Mountain hare (Lepus timidus) in a freshly dug snow hole, Cairngorms National Park, Scotland, UK, December.

Fred Olivier / Close-up of a dominant male Southern elephant seal (Mirounga leonina) calling, Macquarie Island, Sub-Antarctic Australia.

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) group on beach, Galapagos

Denis-Huot / Cheetah (Acinonyx jubatus) resting with rainbow behind it, Masai-Mara Game Reserve, Kenya. September.

John & Mary-Lou Aitchison / Female European otter (Lutra lutra) grooming her cub on a rock, with the cub falling off and into the water, Scotland, UK, November.

John & Mary-Lou Aitchison / Female European otter (Lutra lutra) bringing a fish to a juvenile sleeping on a rock, Scotland, UK, November.

Andy Rouse / Giant panda (Ailuropoda melanoleuca) cub aged five months falling asleep in a tree in a breeding centre, Chengdu, China. Captive.

Ingo Arndt / Harp seal (Phoca groenlandicus) pup sleeping on sea ice, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Ingo Arndt / Grizzly Bear (Ursus arctos horribilis) two cubs resting, Lake Clark National Park, Alaska, USA, August

Ingo Arndt / Gentoo Penguin (Pygoscelis papua) sleeping on beach, Volunteer Point, Falkland Islands, March

Ingo Arndt / Fisheries Protection Vessel (Pharos) arrived at King Edward Point with King penguins on shoreline, South Georgia Heritage Trust Rat Eradication Project, South Georgia, February 2011

Francois Savigny / Male lion crouching on ground {Panthera leo} Southern Africa,

Ingo Arndt / Epauletted bat roosting {Epomops buettikoferi} Komeo NP, Ivory Coast

Francois Savigny / Polar bear and cub asleep on drifting iceberg, summer, Svalbard, Norway

Ingo Arndt / Gelada baboon troop on rock {Theropithecus gelada} Simien Mt NP, Ethiopia

Danny Green / Three Sea otters (Enhydra lutris) resting on ice, Alaska, June

Francisco Marquez / Common crane (Grus grus) in a blizzard, Gallocanta Lake, Aragon, Spain, February.

Eric Baccega / Female Harp seal (Phoca groenlandicus) surfacing at breathing hole looking at her pup, Magdalen Islands, Gulf of St Lawrence, Quebec, Canada, March.

Edwin Giesbers / Banded demoiselle (Calopteryx splendens) males resting on grass, Netherlands, August.

Edwin Giesbers / RF - Banded darter (Sympetrum pedemontanum) group of five resting, Netherlands, September. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF - Banded demoiselle (Calopteryx splendens) two males resting, Netherlands, August. (This image may be licensed either as rights managed or royalty free.)

Markus Varesvuo / Snowy owl (Bubo scandiaca) female sitting among snow covered vegetation on ground, Canada February

Claudio Contreras / American crocodile (Crocodylus acutus) split level with animal resting at surface in shallow water over seagrass bed, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

Claudio Contreras / American crocodile (Crocodylus acutus) resting just above seagrass underwater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico

SCOTLAND: The Big Picture / A family of otters rest on the intertidal seaweed. European river otter (Lutra lutra) Shetland, Scotland, UK, July.

Bernard Castelein / Ankarana sportive lemur (Lepilemur ankaranensis), Ankarana National Park, Madagascar