Neil Aldridge / Lion cub (Panthera leo) calling to its mother from the raised deck of a tourist lodge in the middle of the Busanga Plains, Kafue National Park, Zambia. Vulnerable species.

Neil Aldridge / Lion cub (Panthera leo) playfully attacking its mother as she drags her puku antelope prey across burnt Busanga Plains, Kafue National Park, Zambia. Vulnerable

Will Burrard-Lucas / Spotted hyena (Crocuta crocuta) at night, taken with remote camera. Liuwa Plain National Park, Zambia. December

Will Burrard-Lucas / Spotted hyena (Crocuta crocuta) low angle shot of group taken with remote camera. Liuwa Plain National Park, Zambia. May

Michel Roggo / Aerial view of Victoria Falls Waterfall, Zambezi River at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. Photographed for The Freshwater Project in July...

Michel Roggo / Aerial view of Victoria Falls Waterfall, Zambezi River at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. Photographed for The Freshwater Project in July...

Michel Roggo / Aerial view of Victoria Falls Waterfall, Zambezi River at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. Photographed for The Freshwater Project in July...

Michel Roggo / African bush elephants (Loxodonta africana) wading through Zambezi River, upstream of the Victoria Falls at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site...

Michel Roggo / African bush elephants (Loxodonta africana) wading through Zambezi River, upstream of the Victoria Falls at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site...

Michel Roggo / Zambezi River upstream of Victoria falls at sunset, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. At the border of Zimbabwe and Zambia, Photographed for The Freshwater Project.

Michel Roggo / Victoria Falls Waterfall, Zambezi River at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. Photographed for The Freshwater Project in July 2014

Michel Roggo / Victoria Falls Waterfall, Zambezi River at the border of Zimbabwe and Zambia, Mosi-oa-Tunya / Victoria Falls UNESCO World Heritage Site. Photographed for The Freshwater Project in July 2014

Chase Dekker / Humpback Whale (Megaptera novaeangliae) pod gulp feeding on Northern Anchovy (Engraulis mordax), Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) calf breaching, Monterey Bay, California

Chase Dekker / Humpback Whale (Megaptera novaeangliae) breaching at sunset, Monterey Bay, California

Chase Dekker / African Lion (Panthera leo) male, Masai Mara, Kenya

Chase Dekker / African Lion (Panthera leo) cub, Masai Mara, Kenya

Chase Dekker / Lesser Flamingo (Phoenicopterus minor) wading, Amboseli National Park, Kenya

Chase Dekker / Lesser Flamingo (Phoenicopterus minor) pair fighting, Amboseli National Park, Kenya

Chase Dekker / Humpback Whale (Megaptera novaeangliae) breaching, Monterey Bay, California

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

Marie Read / American avocets (Recurvirostra americana) two during aggressive (territorial) encounter, Bear River Migratory Bird Refuge, Utah, USA, May.