Ann & Steve Toon / RF - Lion (Panthera leo) head portrait at night, Zimanga private game reserve, KwaZulu-Natal, South Africa. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Polar bear (Ursus maritimus) male walking through snow covered landscape, mountains in background. Svalbard, Norway, April (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Arctic fox (Alopex lagopus) in winter pelage, camouflaged in snow. Svalbard, Norway, April (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Arctic fox (Alopex lagopus) sitting with summer pelage, tuft of fur on head. Svalbard, Norway, July. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Reindeer (Rangifer tarandus) walking up slope in snow. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Polar bear (Ursus maritimus) cub walking in snow. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Danny Green / RF - Polar bear (Ursus maritimus) female walking across ice. Svalbard, Norway, April. (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - Red fox (Vulpes vulpes) foraging in snow covered valley. Hayden Valley, Yellowstone National Park, USA. February 2019. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF - Pied kingfisher (Ceryle rudis) group of three perched on branch, squabbling, Zimanga Private Nature Reserve, KwaZulu Natal, South Africa

Staffan Widstrand / RF - African bush elephant, (Loxodonta africana) at night, reflected in waterhole, South Africa

Alex Mustard / RF - Silhouette of a California sea lion (Zalophus californianus) swimming through an underwater cave. Los Islotes, La Paz, Baja California Sur, Mexico. Sea of Cortez, Gulf of California, East Pacific...

Alex Mustard / RF - Portrait of Coral hermit crab (Paguritta harmsi) living in a hard coral colony. North Male Atoll, Maldives. Indian Ocean (This image may be licensed either as rights managed or royalty free.)