Heather Angel / Giant panda (Ailuropoda melanoleuca) sliding down slope on back after losing footing. Panda Breeding Centre, Wolong, Sichuan, China. January 1987.

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

Lucas Bustamante / Sri Lankan leopard (Panthera pardus kotiya) rolling on its back, Yala National Park, Sri Lanka

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) chicks lying down in the cold, Atka Bay, Queen Maud Land, Antarctica. October.

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

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

Dave Watts / Female Western grey kangaroo (Macropus fuliginosus) rolling with a large joey in her pouch, Kangaroo Island, South Australia.

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

Frederique Olivier / Adelie penguin (Pygoscelis adeliae) lying down to incubate an egg, Antarctica.

Mark Taylor / Yellow Labrador Retriever puppy, age 9 weeks, lying with head up.

Mark Taylor / Tabby kitten, 6 weeks, lying with head up and raised paw.

Pal Hermansen / Inuit sled dogs resting, near Ittoqortoormiit, Scoresbysund, Greenland. Second Prize in the Nature category of the Spider Black and White Photography Competition 2015.