Phil Savoie / Painted nomad bee (Nomada fucata) male bee with characteristic green eyes, sleeping with jaws locked around grass stem, Monmouthshire, Wales, UK. June

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) mother watching cub catching salmon, Katmai National Park, Alaska, USA, August

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

John MacPherson / Reindeer (Rangifer tarandus) fighting, Cairngorms National Park, Scotland, UK, March.

Staffan Widstrand / Two Svalbard reindeer (Rangifer tarandus platyrhynchus) fighting; antlers shedding velvet; Spitsbergen, Svalbard, Norway, September

Denis-Huot / Two male Thomson's gazelles (Eudorcas thomsonii) fighting, Masai-Mara game reserve, Kenya.

Michel Roggo / Brown bear (Ursus arctos beringianus) fishing for Sockeye salmon in the Ozernaya River, Kamtchatka, Russia, August

Eric Medard / Ibex (Capra ibex) males fighting, Jura, Switzerland, captive

Alex Mustard,Alex Mustard / A female (in front) and male Sockeye salmon (Oncorhynchus nerka) over eggs in their spawning river. Adams River, British Columbia, Canada, October.

Alex Mustard / A split level photo of group of Sockeye salmon (Oncorhynchus nerka) fighting their way upstream as they migrate back to the river of their birth to spawn, trees showing autumnal colours. Adams River,...

Jack Dykinga / Rain spattered inter-locking palm leaves create a design of pattern and colour in the tropical rainforest. Osa Peninsula, Costa Rica

Michel Roggo / Sockeye / Red Salmon (Oncorhynchus nerka) on spawning migration; males surrounding a female. Adams River, British Columbia, Canada, October.

Michel Roggo / Sockeye / Red Salmon (Oncorhynchus nerka) on spawning migration. Adams River, British Columbia, Canada, October.

Phil Savoie / Painted nomad bee (Nomada fucata) male with characteristic green eyes, sleeping with jaws locked onto grass blade, Monmouthshire, Wales, UK. April

Shane Gross / Marine biologist Dr. Heather Masonjones tags a seahorse (Hippocampus erectus) to study a land locked alakaline lagoon's population. Through this method of injecting a non-toxic dye that can only b...

Shane Gross / Lined seahorse (Hippocampus erectus) holding onto a red mangrove shoot in a land locked alkaline lagoon on Eleuthera, Bahamas.

Shane Gross / Atlantic Palolo (Eunice fucata) looking for food just before retreating back into her burrow, in land locked alakaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Caribbean reef octopus (Octopus briareus) hunting in a land locked alkaline lagoon, The Bahamas.

Shane Gross / Marine biologist Dr. Heather Masonjones tags a seahorse (Hippocampus erectus) to study a land locked alakaline lagoon's population. Through this method of injecting a non-toxic dye, that can only...

Shane Gross / Lined seahorse (Hippocampus erectus) swimming among algae in a land locked alakaline lagoon on Eleuthera, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) holding onto a red mangrove root in a land locked alakaline lagoon on Eleuthera, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) clinging to coral in a land locked alakaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Burrfish (Chilomycterus schoepfi) swimming above an algae bed at night in a land locked alakaline lagoon on Eleuthera, Bahamas.

Shane Gross / Houndfish (Tylosurus crocodilus) at night in a land locked alakaline lagoon on Eleuthera, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) clinging to algae in a land locked alakaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) male clining to algae in a land locked alakaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) clinging to algae in a land locked alakaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) camouflaged holding onto a tree branch near the surface in a land locked alakaline lagoon on Eleuthera, Bahamas.

Shane Gross / Aerial view of an inland land locked alkaline lagoon on Eleuthera Island, Bahamas. February 2018.

Shane Gross / Caribbean reef octopus (Octopus briareus) hunting in a land locked alakaline lagoon in The Bahamas.

Shane Gross / Lined seahorse (Hippocampus erectus) male clinging to algae in a land locked alkaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Lined seahorses (Hippocampus erectus), one male and one female, clinging to algae in a land locked alkaline lagoon on Eleuthera Island, Bahamas.

Shane Gross / Nudibranch (Dondice occidentalis) feeding on algae in a land locked alakaline lagoon on Eleuthera, Bahamas.

Jack Dykinga / Cracked mud patterns across the valley floor. This mud came from a mudslide and boulders and vegetation were locked into place by the river of mud. Bandwater, Death Valley National Park, Mojave Dese...

Juan Carlos Munoz / Door at Malla's Royal Palace, Bhaktapur Durbar Square Complex, Durbar Marg, Lalitpur Metropolitan City, Kathmandu Valley, Nepal. February 2018.

Ashley Cooper / Derwent Water completely frozen over with cycle tracks, Keswick, Lake District, England, UK, December 2010.

Ashley Cooper / Derwent Water completely frozen over with cycle tracks, Keswick, Lake District, England, UK, December 2010.

Ashley Cooper / Derwent Water at Keswick in the Lake District completely frozen over during the December 2010 big chill, with footsteps from a walker who walked across the lake. December 2010

Ashley Cooper / Bikes in bike racks in Amsterdam, Netherlands. A huge percentage of the population cycle in this flat, low lying country. April 2013.

Michel Roggo / Brown bear (Ursus arctos), fishing for Sockeye salmon (Oncorhynchus nerka) in the Ozernaya River, Kuril Lake, South Kamtchatka Sanctuary, Far East Russia. August.

Michel Roggo / Underwater view of Brown bear (Ursus arctos) paw fishing for Sockeye salmon (Oncorhynchus nerka) with paw outstretched. Ozernaya River, Kuril Lake, South Kamtchatka Sanctuary, Far East Russia. August.

Michel Roggo / Mass of dead Sockeye Salmon (Oncorhynchus nerka) after spawning, British Columbia, Canada, October. Photographed for the Freshwater Project.

Michel Roggo / Sockeye Salmon (Oncorhynchus nerka) on spawning ground in groundwater channel, with trees cut by beavers Adams river, British Columbia, Canada, October. Photographed for the Freshwater Project.

Ingo Arndt / Sockeye Salmon (Oncorhynchus nerka) swimming upstream during spawning run (aerial photo), Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Fishery workers counting Sockeye Salmon (Oncorhynchus nerka) aerial photo. Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Sockeye Salmon (Oncorhynchus nerka) swimming upstream during spawning run (aerial photo). A few dead animals visible on left side. Adams River, Roderick Haig-Brown Provincial Park, British Columbia, C...

Ingo Arndt / Sockeye salmon (Oncorhynchus nerka) group swimming upstream during spawning run, Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Sockeye salmon (Oncorhynchus nerka) group swimming upstream during spawning run, Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Wildlife Photographer Ingo Arndt taking underwater pictures of sockeye salmon (Oncorhynchus nerka). Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Sockeye salmon (Oncorhynchus nerka) dead male after spawning migration. Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Wildlife Photographer Ingo Arndt taking underwater pictures of sockeye salmon (Oncorhynchus nerka). Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Sockeye salmon (Oncorhynchus nerka) dead male after spawning migration. Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada October.

Ingo Arndt / Two Christmas Island Red Crabs (Gecarcoidea natalis) locked in combat, on rocks, Christmas Island, Indian Ocean, Australian Territory

SCOTLAND: The Big Picture / Red deer (Cervus elaphus) stags sparring during rutting season, February.

Eric Baccega / Two male Grizzly bears (Ursus arctos horribilis) in a river, one trying to steal the salmon catch from the other, Brooks River, Katmai National Park, Alaska, USA, July.

Eric Baccega / Three male grizzly bears (Ursus arctos horribilis) fishing for Sockeye salmon ((Oncorhynchus nerka) leaping up a waterfall in Brooks River, Katmai National Park, Alaska, USA, July.

Eric Baccega / Male Grizzly bear (Ursus arctos horribilis) fishing for Sockeye salmon (Oncorhynchus nerka) leaping up a waterfall in Brooks River, Katmai National Park, Alaska, USA, July.

Eric Baccega / Male Grizzly bear (Ursus arctos horribilis) fishing for Sockeye salmon (Oncorhynchus nerka) leaping up a waterfall in Brooks River, Katmai National Park, Alaska, USA, July.

Martin Gabriel / Woodcock murex snail (Murex scolopax), its aperture locked with operculum, Gulf of Oman, Sultanate of Oman, January, CROPPED

Tony Wu / Malabar pied hornbills (Anthracoceros coronatus) pair engaged in an argument, with their beaks locked together and one bird flipping over the other, Yala National Park, Sri Lanka

Wim van den Heever / White-tailed eagles (Haliaeetus albicilla) two with locked talons fighting mid-air in a snow storm, Hokkaido Japan.

Wim van den Heever / White-tailed eagles (Haliaeetus albicilla) two with locked talons fighting mid-air in a snow storm, Hokkaido Japan.

Alex Mustard / Split level photo of group of Sockeye salmon (Oncorhynchus nerka) fighting their way upstream as they migrate back to the river of their birth to spawn, trees showing autumnal colours. Adams River, Br...

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) trying to catch Sockeye salmon, Katmai National Park, Alaska, USA, August.

Loic Poidevin / Sockeye Salmon (Oncorhynchus nerka) male in river during migration, Katmai, Alaska, USA, August.

Loic Poidevin / Sockeye salmon (Oncorhynchus nerka) dead female which has been half eaten, Katmai, Alaska, USA, August.

Jeff Rotman / Family fishing for Sockeye salmon (Oncorhynchus nerka) Graveyard Point, Bristol Bay, Alaska, USA, June. Model released.

Jeff Rotman / Sockeye salmon (Oncorhynchus nerka) caught with set gill net. Graveyard Point, Bristol Bay, Alaska, USA, June. Model released.

Jeff Rotman / Fishermen hauling in set gill net to harvest Sockeye salmon (Oncorhynchus nerka) Graveyard Point, Bristol Bay, Alaska, USA. July 2015. Model released.

Jeff Rotman / Fishermen hauling in set gill net to harvest Sockeye salmon (Oncorhynchus nerka) Graveyard Point, Bristol Bay, Alaska, USA. July 2015. Model released.

Jeff Rotman / Fishermen hauling in Sockeye salmon (Oncorhynchus nerka) in gill net onto boat, Naknek River, Bristol Bay, Alaska, USA, July 2015.

Jeff Rotman / Fishermen haul in set gill net whilst fishing from Sockeye salmon (Oncorhynchus nerka) at night, Graveyard Point, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Fishermen haul in set gill net whilst fishing forSockeye salmon (Oncorhynchus nerka) at night, Graveyard Point, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Fishermen haul in set gill net whilst fishing for Sockeye salmon (Oncorhynchus nerka) at night, Graveyard Point, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Biologists from Alaska Fish and Game catch and sample returning Sockeye salmon (Oncorhynchus nerka) Naknek River, Bristol Bay, Alaska, USA, July 2015.

Jeff Rotman / Sockeye salmon (Oncorhynchus nerka) hauled into boat from net, Bristol Bay, Alaska, USA, July 2015

Jeff Rotman / Leader Creek Fisheries cannery preparing fresh Sockeye salmon (Oncorhynchus nerka) fillets for export worldwide. Naknek, Bristol Bay, Alaska, July 2015.

Jeff Rotman / Young fisherman holding Sockeye salmon (Oncorhynchus nerka) caught using family subsistence license for gill net from shore. Naknek, Bristol Bay, Alaska, USA, June 2015.

Jeff Rotman / The MegJ preparing to drop drift gill net to catch Sockeye salmon (Oncorhynchus nerka) Naknek River, Bristol Bay, Alaska, USA, June 2015.

Jeff Rotman / Biologists from Alaska Fish and Game catching and sample returning Sockeye salmon (Oncorhynchus nerka) Naknek River, Bristol Bay, Alaska, USA, July.

Jeff Rotman / Man with load of Sockeye salmon (Oncorhynchus nerka) loaded directly from tender into factory for processing. This load of fish is in water mixed with blood. Naknek, Bristol Bay, Alaska, USA, July 201...

Jeff Rotman / Sockeye salmon (Oncorhynchus nerka) loaded directly from tender into factory for processing. This load of fish is in water mixed with blood. Naknek, Bristol Bay, Alaska, USA, July 2015.

Jeff Rotman / Commercial fishing boats getting ready to drop net to fish for Sockeye salmon (Oncorhynchus nerka) Naknek River, Bristol Bay, Alaska, USA, July.

Jeff Rotman / Fishermen dropping the net for Sockeye salmon (Oncorhynchus nerka) and trying to outmanoeuvre another boat. Naknek River, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Fisherman bleeding Sockeye salmon (Oncorhynchus nerka) before placing it in cold storage. Naknek River, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Fishing boat dropping the net for Sockeye salmon (Oncorhynchus nerka) and trying to outmanoeuvre other boats. Naknek River, Bristol Bay, Alaska, USA, July 2015.

Jeff Rotman / Fisherman bleeding Sockeye salmon (Oncorhynchus nerka) before placing it in cold storage. Naknek River, Bristol Bay, Alaska, USA, July 2015. Model released.

Jeff Rotman / Large number of fishing boats fishing for Sockeye salmon (Oncorhynchus nerka) using drift gill nets, and trying to out manoeuvre other boats. Naknek River, Bristol Bay, Alaska, USA, July.

Jeff Rotman / Fishing boat fishing for Sockeye salmon (Oncorhynchus nerka) using drift gill nets. Naknek River, Bristol Bay, Alaska, USA, July.

Jeff Rotman / Large number of fishing boats fishing for Sockeye salmon (Oncorhynchus nerka) using drift gill nets, and trying to out manoeuvre other boats. Naknek River, Bristol Bay, Alaska, USA, July.

Jeff Rotman / Fishing boat fishing for Sockeye salmon (Oncorhynchus nerka) using drift gill nets. Naknek River, Bristol Bay, Alaska, USA, July.