Eric Baccega / Grizzly bear (Ursus arctos horribilis) catching salmon in Brooks river, Katmai National Park, Alaska, USA, July

Loic Poidevin / Salmon landing on head of Grizzly bear (Ursus arctos horribilis) as it is leaping up rapids, Katmai National Park, Alaska, USA

Todd Mintz / Sockeye salmon (Oncorhynchus nerka) split level view of annual spawning run, Adams River, British Columbia, Canada, October

Nick Garbutt / Adult male Hippopotamus (Hippopotamus amphibius) posturing in agressive 'yawn' behaviour, Luangwa River, South Luangwa National Park, Zambia, November

Nick Garbutt / Adult male Hippopotamuses (Hippopotamus amphibius) posturing in aggressive 'yawn' behaviour, Luangwa River, South Luangwa National Park, Zambia, November. Digital composite (two frames stitched togeth...

Kim Taylor / Brown Trout (Salmo trutta) juvenile jumping through the water surface to take a hoverfly. Surrey, UK.

Matthew Maran / Black Bear (Ursus americanus) with a Chinook Salmon (Oncorhynchus tshawytscha) in its mouth. Ucluth Inlet, Barkley Sound, Vancouver Island, Canada, September.

Matthew Maran / Black Bear (Ursus americanus) with a Chinook Salmon (Oncorhynchus tshawytscha) in its mouth. West coast of Vancouver Island, Canada, October.

Andy Rouse / Grizzly Bear (Ursus arctos horribilis) walking through a river with caught salmon against a mountainous landscape as two gulls fly past. Katmai, Alaska, USA, August.

Andy Rouse / Grizzly Bear (Ursus arctos horribilis) with caught salmon, another bear more distant, with mountains backing the scene. Katmai, Alaska, USA, August.

Andy Rouse / Grizzly Bear (Ursus arctos horribilis) with caught salmon. Katmai, Alaska, USA, August.

Sergey Gorshkov / Kamchatka Brown bear (Ursus arctos beringianus) catching salmon in river, Kamchatka, Far east Russia, August