Danny Green / Bison (Bison bison) herd walking in line in snow, Yellowstone National Park, Wyoming, USA, February

Ann & Steve Toon / Egyptian goose (Alopochen aegyptiaca) with goslings, Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Ann & Steve Toon / Cape buffalo (Syncerus caffer) at waterhole at night with plains zebra (Equus quagga), Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Ann & Steve Toon / Cape buffalo (Syncerus caffer) drinking at waterhole at night, Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Ann & Steve Toon / Plains zebra (Equus quagga) drinking at waterhole at night, Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Jack Dykinga / Douglas firs (Pseudotsuga menziesii) in 'Wall Street' Canyon. Bryce Canyon National Park, Utah, USA, October.

Jack Dykinga / Lupan Point, looking west into sunset. Grand Canyon National Park, Arizona, USA, August.

SCOTLAND: The Big Picture / Scots pine (Pinus sylvestris) with Northern lights / Aurora borealis lighting up the night sky in background, Monadhliath Mountains, Cairngorms National Park, Scotland, UK, October 2015.

Lorraine Bennery / Knapweed fritillary butterflies (Melitaea phoebe) on Green winged orchid (Anacamptis morio), Grands Causses Regional Natural Park, France, May.

Christophe Courteau / African elephants (Loxodonta africana) swimming across Chobe River, trunks raised above surface for breathing, Chobe National Park, border between Botswana and Namibia.

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) split level with animal resting at surface in shallow water over seagrass bed, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico