Dave Watts / Eastern grey kangaroo (Macropus giganteus) with joey in pouch, Australian Capital Territory, Australia, September

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

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

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) rear view of dominant male silverback 'Makumba' aged 32 years walking along a forest trail, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Cen...

David Pattyn / Red foxes (Vulpes vulpes) two fighting, probably over territory, The Netherlands, August

Martin Dohrn / Maricopa harvester ant (Pogonomyrmex maricopa) fighting a different species of ant (Aphaenogaster cockerelli), over territory Arizona, USA

Andy Rouse / Paperbark or Tea Tree (Melaleuca quinquenervia) forest at sunset, Bamarru Plains, North West Territory, Australia, April 2007

Andrew Parkinson / Whooper swan (Cygnus cygnus) adult aggressively chasing another, UK visitor between November and March. Lancashire, UK, October.

Dave Watts / Eastern grey kangaroo (Macropus giganteus) bounding, Australian Capital Territory, Australia, September

Dave Watts / Eastern grey kangaroo (Macropus giganteus) two males boxing, Australian Capital Territory, Australia, December

Dave Watts / Satin Bowerbird (Ptilonorhynchus violaceus) male arranging blue plastic ornaments and feather at bower, Australian Capital Territory, Australia, September

Ingo Arndt / Saltwater Crocodile (Crocodylus porosus) swimming, Northern Territory, Australia

Andy Rouse / Grizzly Bear (Ursus arctos horribilis) chasing gulls away from his salmon hunting territory. Katmai, Alaska, USA, September.

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)

Roger Powell / Red-legged Partridge (Alectoris rufa) portrait of male perched on a prominent boulder & calling over territory. Castro Verde, Portugal, April

Gerrit Vyn / Adult Red-necked Grebes (Podiceps grisegena) in breeding plumage performing "whinny-braying" duet in defense of territory. Fairbanks, Alaska, USA, July.

Ingo Arndt / Blue Crab (Discoplax hirtipes) in defensive posture, Christmas Island, Indian Ocean, Territory of Australia

Andy Rouse / Aerial view of ice ridges at front of Peters Glacier, King Haakon Bay, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of the wild north east coast of South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of snow covered mountains, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of Warburton Peak, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of a mountain in front of King Haakon Bay, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of Peters Glacier, King Haakon Bay, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of meltwater patterns on Peters Glacier, South Georgia, Antarctica, December 2006

Andy Rouse / Mountains at sunset with lenticular clouds in the sky, South Georgia, January 2006

David Tipling / King Penguin colony {Aptenodytes patagonicus} and Elephant seals, Gold Harbour, South Georgia, November 2006

David Tipling / Lenticular clouds over the mountains bordering Gold Harbour, South Georgia, November 2006

Andy Rouse / Rainbow over the sea with a small iceberg, South Georgia, December 2006

Andy Rouse / Aerial view of Peters Glacier, King Haakon Bay, South Georgia, Antarctica, December 2006

David Tipling / Cruise ship anchored off Hercules Bay, South Georgia, November 2006

Andy Rouse / Bengal Tiger (Panthera tigris tigris) female fighting with her 18-month cub (females fight when it is time for the cubs to move on and find their own territory) Ranthambore NP, Rajasthan, India. Veoli...

Andy Rouse / Bengal tiger (Panthera tigris tigris) female fighting with 18 months cub, Ranthambore NP, Rajasthan, India. They fight when it is time for the cubs to move on and find their own territory

Andy Rouse / Bengal tiger (Panthera tigris tigris) female fighting with 18 months cub, Ranthambore NP, Rajasthan, India. They fight when it is time for the cubs to move on and find their own territory

Andy Rouse / Bengal tiger (Panthera tigris tigris) female fighting with 18 month cub - they fight when it is time for the cubs to move on and find their own territory, India (non-ex)

Wild Wonders of Europe / E Haarberg / Chamois (Rupicapra rupicapra) male marking his territory in rutting season, Gran Paradiso National Park, Italy, November 2008

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

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

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

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

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

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

Theo Allofs / Autumn in the Ogilvie Mountains and boreal forest near the Dempster Highway, Yukon, Canada

Anup Shah / Male African lion {Panthera leo} trotting across his territory to see of an intruder, Masai Mara GR, Kenya. Lions can run at speeds of 50mph!

Anup Shah / Simien jackal / Ethiopian wolf {Canis simensis} marking territory by scraping, Bale Mountains, Bale NP, Ethiopia

Igor Shpilenok / Male Kamchatka Brown bear (Ursus arctos beringianus) marks trunk of Stone birch to denote territory during mating season, Valley of the Geysers, Kronotsky Zapovednik Reserve, Kamchatka, Russia.

Pete Oxford / Iceberg - Bergy Bit, Cape Darnley, Australian Antarctic Territory

Pete Oxford / Emperor penguin feeding chick. (Aptenodytes forsteri) Australian Antarctic territory

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

Gary Smith / Pheasant {Phasianus colchicus} males fighting over territory, Norfolk, UK.

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

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

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

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

Staffan Widstrand / White water river rafting, Yukon, Canada.

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

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

Jim Brandenburg / Arctic Wolf (Canis lupus) pack hunting Muskox (Ovibos moschatus) herd, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Polar Bear (Ursus maritimus) walking across ice floes, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) juvenile male babysitting pups, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) alpha male known as Buster, smelling Arctic Poppy (Papaver lapponicum) flowers, Ellesmere Island, Nunavut, Canada

Patricio Robles Gil / St. Elias Mountains, Kluane National Park, Canada

Patricio Robles Gil / Glacier, St. Elias Mountain, Kluane National Park, Canada

Flip Nicklin / Polar Bear (Ursus maritimus) hauling out on ice floe, Wager Bay, Canada

Michael & Patricia Fogden / Bredl's Carpet Python (Morelia bredli) coiled on rock ledge on mountain side, Trephina Gorge National Park, MacDonnell Ranges, Australia

Michael & Patricia Fogden / Ramsay's Python (Aspidites ramsayi) in the desert near Ayers Rock, Uluru-Kata Tjuta National Park, Australia

Michael & Patricia Fogden / Thorny Devil (Moloch horridus) in the desert near Ayers Rock, Uluru-Kata Tjuta National Park, Australia

Thomas Mangelsen / Peregrine Falcon (Falco peregrinus) flying, Wager Bay, Northwest Territories, Canada

Pete Oxford / Emperor Penguin (Aptenodytes forsteri) pair, Flutter EP Rookery, Cape Darnley, Australian Antarctic Territory, Antarctica

Tim Fitzharris / Pond reflecting Nisling Range, Yukon Territory, Canada

Michael & Patricia Fogden / Southern Grasshopper Mouse (Onychomys torridus) male singing on its territory, Chihuahua Desert, Mexico

Jim Brandenburg / Aerial view of converging glacier, Ellesmere Island, Nunavut, Canada

Sumio Harada / Red Squirrel (Tamiasciurus hudsonicus) mother protecting territory near her nest from other squirrels, Rocky Mountains, North America

Gerry Ellis / Great Bowerbird (Chlamydera nuchalis) male in courting bower, Katherine Gorge National Park, Australia

Matthias Breiter / Rainbow Lorikeet (Trichoglossus haematodus) on branch, Noonamah, Northern Territory, Australia

Matthias Breiter / Rainbow Lorikeet (Trichoglossus haematodus) pair interacting, Noonamah, Northern Territory, Australia

Jim Brandenburg / Iceberg in pack ice, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Inuits dog sledding in midnight sun, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) pups, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) on ice floe, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) pack on ice field, Ellesmere Island, Nunavut, Canada

Flip Nicklin / Polar Bear (Ursus maritimus) about to haul out on ice floe, Wager Bay, Canada

Jim Brandenburg / Arctic Hare (Lepus arcticus) camouflaged on snow, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Polar Bear (Ursus maritimus) jumping out of water, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) juveniles playing, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Fox (Alopex lagopus) smelling snow, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) leaping onto ice floe, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) on ice floe, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) male on iceberg, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Arctic Wolf (Canis lupus) adult at den site, Ellesmere Island, Nunavut, Canada

Jim Brandenburg / Peary Caribou (Rangifer tarandus pearyi) pair running, Ellesmere Island, Nunavut, Canada