Wim van den Heever / Thomson's gazelle (Eudorcas thomsonii) square off for a territorial battle, Ngorongoro Crater, Tanzania

Steven Kazlowski / Young Polar bear (Ursus maritimus) walking on newly formed pack ice, near Kaktovik, Barter Island, North Slope, Alaska, USA, October. Vulnerable species.

Steven Kazlowski / Polar bear (Ursus maritimus) portrait against sky at sunset, Bernard Spit, off the 1002 Area, Arctic National Wildlife Refuge, North Slope, Alaska, USA, September. Vulnerable species.

Andy Rouse / Polar Bear (Ursus maritimus) cubs climbing rocks. Svalbard, Norway. July.

Steven Kazlowski / Two Polar bear (Ursus maritimus) cubs playing, on newly formed pack ice, off the 1002 Area, Arctic National Wildlife Refuge, North Slope, Alaska, USA, October. Vulnerable species.

Steven Kazlowski / Young Polar bear (Ursus maritimus) walking on newly formed pack ice, near Kaktovik, Barter Island, North Slope, Alaska, USA, October. Vulnerable species.

Steven Kazlowski / Polar bear (Ursus maritimus) sow with two cubs walking past a pile of Bowhead whale (Balaena mysticetus) bones, Kaktovik, Barter Island, 1002 Area, Arctic National Wildlife Refuge, North Slope, Alaska...

Steven Kazlowski / Young Polar bear (Ursus maritimus) standing on hind legs, Bernard Spit, 1002 Area, Arctic National Wildlife Refuge, North Slope, Alaska, USA, October. Vulnerable species.

Steven Kazlowski / Two young Polar bears (Ursus maritimus) on newly formed pack ice, near Kaktovik, Barter Island, North Slope, Alaska, USA, October. Vulnerable species.

Pal Hermansen / Domestic reindeer herd (Rangifer tarandus) group close together in enclosure, Oppland, Norway, September 2014.

Pal Hermansen / Domestic reindeer herd (Rangifer tarandus) group close together in enclosure, Oppland, Norway, September 2014.

Pal Hermansen / Reindeer (Rangifer tarandus) male and female, Forolhogna National Park, Hedmark, Norway.

Eric Baccega / Young boy, Nenet herder practising lasso, wearing traditional malitsa coat. Yar-Sale district, Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / Pet reindeer ""akva"" (Rangifer tarandus) with Nenet herders resting before spring migration. Yar-Sale district, Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / Nenet herder inside tent with daughter and sons, wearing coats made with reindeer skin and fur. Yar-Sale district. Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / Nenet woman at entrance of tent in blizzard. Yar-Sale district. Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / A tundra nenets woman with her ""akva"" pet reindeer (Rangifer tarandus), Yar-Sale district, Yamal, Northwest Siberia, Russia, April 2016

Eric Baccega / Nenet herders erecting tent on tundra. Yar-Sale district, Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / Reindeer (Rangifer tarandus) herd migrating in spring at dusk under moon. Yar-Sale district, Yamal, Northwest Siberia, Russia. April.

Eric Baccega / Ekaterina Yaptik, Nenet woman leading Reindeer (Rangifer tarandus) on spring migration in tundra with child in sled. Yar-Sale district, Yamal, Northwest Siberia, Russia. April 2016.

Eric Baccega / Nenet woman leading Reindeer (Rangifer tarandus) sleds on spring migration across tundra. Yar-Sale district, Yamal, Northwest Siberia, Russia. April 2016.

Bence Mate / European otters (Lutra lutra) feeding on fish at night, backlit, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. October.

Andy Rouse / Red Fox (Vulpes vulpes) urban Cardiff, Wales. May.

Pete Oxford / Agua Rica leaf frog (Phyllomedusa ecuatoriana) captive, endemic to Agua Rica, Ecuador. Endangered species.

Pete Oxford / Agua Rica leaf frog (Phyllomedusa ecuatoriana) captive, endemic to Agua Rica, Ecuador. Endangered species.

Pete Oxford / San Lucas marsupial frog (Gastrotheca pseustes) captive, occurs in Ecuadorian Andes.

Pete Oxford / Tiger tree frog (Hyloscirtus tigrinus) captive, endemic to Ecuador.

Pete Oxford / Espada's marsupial frog (Gastrotheca testudinea) captive, occurs in Bolivia, Ecuador, and Peru.

Pete Oxford / Pebas stubfoot toad (Atelopus spumarius) captive occurs in the Amazon Basin. Vulnerable species.

Pete Oxford / Agua Rica leaf frog (Phyllomedusa ecuatoriana) captive, endemic to Agua Rica, Ecuador. Endangered species.

Michael Hutchinson / Presenter Nigel Marven holding King cobra (Ophiophagus hannah) China, May 2013. Model released.

Michael Hutchinson / Presenter Nigel Marven with Spectacled cobra (Naja naja) in a paddy field, India. November 2015. Model released.

Ann & Steve Toon / Atlantic salmon (Salmo salar) leaping on upstream migration, River Tyne, Hexham, Northumberland, UK, November

Graham Eaton / An Atlantic Salmon (Salmo salar) jumping a waterfall in autumn on the River (Afon) Lledr, Betws-y-Coed, Wales October

Pal Hermansen / Garden cross spider (Araneus diadematus) on web, Norway.

Rod Williams / Greenbottle (Lucilia sp) on Everlasting sweet pea flower, Brockley Cemetery, Lewisham, London, England, August.

Alex Hyde / Goldenrod Crab Spider (Misumena vatia) female waiting to ambush insect prey on Greater Burnet-saxifrage (Pimpinella major) Nordtirol, Austrian Alps. June.

Nick Upton / Spotted longhorn beetle (Rutpela maculata) feeding on a Field scabious flower (Knautia arvensis) in a chalk grassland meadow, Wiltshire, UK, July.

John Abbott / Halloween pennant (Celithemis eponina) male in flight, Texas, USA, August.

Pal Hermansen / Hoverfly in flight, backlight, Norway, September.

Michael Hutchinson / Six-spot burnet moth (Zygaena filipendulae) on dandelion flower in meadow, Ashton Court Park, Bristol, UK, June.

John Abbott / Green Mantisfly (Zeugomantispa minuta) in flight, Texas, USA, June.

Alex Hyde / Raft Spider (Dolomedes fimbriatus) female resting on the surface of a moorland pool among stems of Horsetail (Equisetum sp.). Nordtirol, Austrian Alps, June.

Ann & Steve Toon / Spring wild flowers, Oudrif farm, Cederberg, Western Cape, South Africa, August 2015

Alex Hyde / Burnt / Burnt-tip Orchid (Orchis ustulata) flowering in ancient alpine meadow. Nordtirol, Austrian Alps. June.

Pal Hermansen / Purple gentian (Gentiana purpurea) in flower, Norway, September.

Alex Hyde / Dandelion (Taraxacum officinale) close up of seedhead or 'clock', Nordtirol, Austrian Alps. June.

Ann & Steve Toon / Spring wildflowers, Papkuilsfontein farm, Nieuwoudtville, Northern Cape, South Africa, September 2015

Ann & Steve Toon / Spring wildflowers, Papkuilsfontein farm, Nieuwoudtville, Northern Cape, South Africa, September 2015

Ann & Steve Toon / Yellow cat's tail (Bulbinella latifolia) formerly (Bulbinella floribunda), Papkuilsfontein farm, Nieuwoudtville, Northern Cape, South Africa, September 2015

Ann & Steve Toon / Spring wildflowers, Papkuilsfontein farm, Nieuwoudtville, Northern Cape, South Africa, September 2015

Alex Hyde / Trumpet / Stemless Gentian flower (Gentiana acaulis) looking down the middle of the flower, showing five-fold symmetry. Nordtirol, Austrian Alps. June.

Ann & Steve Toon / Pincushion protea (Leucospermum cordifolium), Kirstenbosch Botanical Gardens, Cape Town, South Africa

Rod Williams / Two Seven-spot ladybirds (Coccinella septempunctata) feeding on Tansy (Tanacetum vulgare) Brockley, Lewisham, London, England, July.

Michael Hutchinson / Green-winged orchids (Anacamptis morio) at sunrise, Ashton Court Park, Bristol, UK, May

Michael Hutchinson / Common poppy (Papaver rhoeas) growing on street pavement, Bristol, UK, January.

Pal Hermansen / Mountains reflected in Jaegervatnet Lake seen from between trees, Troms, Northern Norway, June 2013.

Pal Hermansen / Spherical stone on Champ Island, Franz Josef Land, Russia, July 2004.

Bernard Castelein / Tsaranoro massif, Andringitra NP, Madagascar, October 2015

Pal Hermansen / Coastal landscape in snow blizzard, Hornya, Finnmark, Norway March 2014

Wim van den Heever / Thunder storm with lightning over the Okavango Delta swamp, Botswana

Graham Eaton / South Stack Lighthouse and RSPB reserve, in a storm, Anglesey, Wales May 2012

Mark Taylor / Rotting wooden shed covered in moss, Washington State, USA.

Bence Mate / Grass fire at night in Pantanal, Brazil.

Pal Hermansen / Foggy lake in autumn landscape, Akershus, Norway, October.

Wim van den Heever / A misty sunrise over tree silhouette in Deadvlei, Namibia

Graham Eaton / Forest trees and peat, which were covered by the sea following the last ice age, exposed on beach at low tide, Borth, Wales. September.

Pal Hermansen / View from Reinebringen at dusk, Moskenes, Lofoten, Norway, August 2013.

Wim van den Heever / Table Mountain viewed from across the sea at sunset, Cape Town, South Africa

Wim van den Heever / Lightning storm over city at night, Pretoria, South Africa December 2013

Andy Rouse / Iceberg and mountain, Svalbard, Norway. Arctic. July.

Wim van den Heever / Aerial view of Cape Town city with Table Mountain, South Africa, taken from helicopter, May 2011

Zoltan Nagy / Aerial view of deforestation in the ?ureanu Mountains. Carpathians, Romania. October, 2014.

Wim van den Heever / Aerial view of Okavango Delta swamp in Botswana 2011

Wim van den Heever / Umbrella Thorn tree (Vachellia tortilis) at night with campsite below and stars above, Lake Ndutu Tanzania

Graham Eaton / St Cwyfans Church, on tiny island of Porth Cwyfan, near Aberffraw, Anglesey, Wales. March.

Pal Hermansen / The first structures of new ice, Norway

Alex Hyde / Full moon rising over the Verpeilspitze (3430m). This peak is part of the Glockturmkamm, the westernmost ridge of the Otztal Alps. Nordtirol, Austrian Alps. July. Digitally stitched panorama.