Michael Pitts / Saltwater crocodile underwater {Crocodylus porosus} Kakadu NP, NT, Australia

Etienne Littlefair / Mertens' water monitor (Varanus mertensi) in water, split level view, Adelaide River, Northern Territory, Australia. October. Winner of the threatened species criteria in Australia Geographic Natu...

Etienne Littlefair / Papuan lynx spider (Oxyopes papuanus), Adelaide River, Northern Territory, Australia, March.

Etienne Littlefair / Green ant mimic spider (Myrmarachne smaragdina), adult female hunting, Darwin, Northern Territory, Australia, March.

Etienne Littlefair / Eyrean Grasswren (Amytornis goyderi) in typical hopping motion, Andado Station, Northern Territory, Australia, November.

Steven David Miller / Red-collared lorikeet (Trichoglossus rubritorquis) pair examining hole in Eucalyptus as a potential nesting hollow. Katherine, Northern Territory, Australia.

Steven David Miller / A Perentie (Varanus giganteus) using its forked tongue to detect smells, Alice Springs Reptile Centre, Northern Territory, Australia, Captive. May.

Paul Williams / Budgerigars (Melopsittacus undulatus) flocking to find water, Northern Territory, Australia

Juergen Freund / Wangi Falls at night illuminated by moonlight, Litchfield National Park, Northern Territory, Australia. December 2012.

Juergen Freund / Dingo (Canis lupus dingo) at Devils Marbles, Northern Territory, Australia.

Juergen Freund / Flock of Budgerigars (Melopsittacus undulatus ) drinking in an outback dam, Northern Territory, Australia.

Juergen Freund / Banded archerfish (Toxotes jaculatrix) spitting, Oolioo Sandbar, Territory Wildlife Park, Berry Springs, Northern Territory, Australia.

Ingo Arndt / Cathedral Termite mount, Litchfield National Park, Northern Territory, Australia

Ingo Arndt / Magnetic termite (Amitermes meridionalis) aerial view of mounds in grassland, Litchfield National Park, Northern Territory, Australia.

Ingo Arndt / Magnetic termite (Amitermes meridionalis) aerial view of mounds in grassland, Litchfield National Park, Northern Territory, Australia.

Ingo Arndt / Magnetic Termite (Amitermes meridionalis) mounds in grassland, Litchfield National Park, Northern Territory, Australia.

Ingo Arndt / Green tree ant (Oecophylla smaragdina) group on entrance from nest, built from woven leaves, Northern Territory, Kakadu National Park, Australia.

Enrique López-Tapia de Inés / Trango towers in fog, the world's tallest cliffs, Baltoro Glacier, Baltistan, part of the Gilgit-Baltistan territory, northern Pakistan. July 2007.

Steven David Miller / Devils Marbles, Devils Marbles Conservation Reserve, Northern Territory, Australia, June 2010

Steven David Miller / Whistling kites (Haliastur sphenurus) two in flight, one with prey in talons, over Corroboree Billabong, Mary River, Northern Territory, Australia

Ingo Arndt / Floodplain with Pandanus palms under storm clouds, Kakadu National Park, Northern Territory, Australia, December 2010

Ingo Arndt / Aboriginal Rock Art / depicting human figure / Anbangbang Gallery / Nourlangie Range / Kakadu National Park, Northern Territory, Australia

Ingo Arndt / Intermediate Egret (Egretta intermedia) Kakadu National Park, Northern Territory, Australia, December

Andrew Parkinson / Pair of Great skuas (Stercorarius skua) on a misty moorland with person walking close to their territory. Shetland Islands, Scotland, UK, June. (non-ex)

Steven David Miller / Large solar panels for generating electricity by solar power, Hermannsburg, west of Alice Springs, Northern Territory, Australia, August 2007

Steven David Miller / Large solar panels for generating electricity by solar power, Hermannsburg, west of Alice Springs, Northern Territory, Australia, August 2007

Jouan & Rius / Misty morning along Yellow Water, South Alligator River floodplain, Kakadu National Park, Northern Territory, Australia

Jouan & Rius / Granite boulder of Devils Marbles, Karlu Karlu Conservation Reserve, Northern Territory, Australia

Jouan & Rius / Bush fire during dry season, Northern Territory, Australia

Jouan & Rius / Bush fire during dry season, Northern Territory, Australia

Jouan & Rius / Aboriginal rock art showing sailing boat, Nanguluwur Gallery, Nourlangie Ranges, Kakadu National Park, Northern Territory, Australia

Jouan & Rius / Aboriginal rock art, Anbangbang Gallery, Nourlangie Ranges, Kakadu National Park, Northern Territory, Australia

Jouan & Rius / Paperbark gum trees (Melaleuca sp) growing along Yellow Water, South Alligator River floodplain, Kakadu National Park, Northern Territory, Australia

Jouan & Rius / Ghost Gum (Eucalyptus / Corymbia papuana) growing amongst granite boulders of Devils Marbles, Karlu Karlu Conservation Reserve, Northern Territory, Australia

Jouan & Rius / Stanley Chasm, a narrow cleft of 80m height, MacDonnell Ranges Northern Territory, Australia

Jouan & Rius / Eucalyptus tree {Eucalyptus centralis} growing beside Uluru / Ayer's Rock, Uluru / Kata Tjuta National Park, Northern Territory, Australia

Pete Cairns / Cuckoo (Cuculus canorus) two males fighting over territory. Cairngorms NP, Scotland, UK.

Michael Pitts / Saltwater crocodile hatchling on adult's head {Crocodylus porosus} NT, Australia

Michael Pitts / Mertens water monitor swimming {Varanus mertensi} Litchfield NP Australia

Tony Heald / 'Cool burn' fire, canopy is unaffected, Kakadu NP, Northern Territory, Australia

David Noton / Panoramic view of Ayer's rock (Uluru) Northern Territories, Australia

Angelo Gandolfi / Saltwater (Estuarine) crocodile {Crocodylus porosus} Northern Territory, Australia

Steven David Miller / Perentie {Varanus giganteus} Northern Territory, Australia, Alice Springs Reptile Park - largest Australian monitor lizard

Staffan Widstrand / Arctic fox resting {Vulpes lagopus} Ellesmere, Northern territory, Canada.

Staffan Widstrand / Arctic fox on snow {Vulpes lagopus} Ellesmere, NorthernTerritory, Canada.

Staffan Widstrand / Arctic fox portrait {Vulpes lagopus} Ellesmere Northern territory, Canada.

Staffan Widstrand / Arctic fox on snow. {Vulpes lagopus} Ellesmere Northern territory, Canada.

David Curl / Lightning over Ayers Rock, Uluru NP, Northern Territory, Australia, desert