Tony Heald / Hippopotamus {Hippopotamus amphibius} territorial defense at water edge, Chobe national park, Botswana.

Tony Heald / Fur pattern detail from Cheetah pelt {Acinonyx jubatus}

Tony Heald / Red Deer (Cervus elaphus) stags fighting during the rutting season. Bushy Park, London, UK. October.

Tony Heald / African buffalo (Syncerus caffer) herd showing defensive behaviour as an African lioness (Panthera leo) walks by, Mana Pools National Park, Zimbabwe. September....

Tony Heald / Lion (Panthera leo) moving away from a defensive African buffalo (Syncerus caffer) Mana Pools National Park, Zimbabwe.

Tony Heald / African elephant (Loxodonta africana) reaching up for foliage, Mana Pools National Park, Zimbabwe.

Tony Heald / African elephant (Loxodonta africana) reaching up for foliage. Mana Pools National Park, Zimbabwe.

Tony Heald / African wild dog (Lycaon pictus) portrait. Chobe National Park Botswana. Digitally enhanced sepia image.

Tony Heald / Elephant (Loxodonta africana) babies playing, Etosha National Park,Namibia.

Tony Heald / Glaucous Gull (Larus hyperboreus) taking off from ice, Svalbard Norway, July.

Tony Heald / Hippopotamus (Hippopotamus amphibius) splashing in pool in evening light. Mana Pools National Park, Zimbabwe.

Tony Heald / African elephant (Loxodonta africana) feeding on grasses, Chobe River, Chobe National Park, Botswana. May.

Tony Heald / African lion (Panthera leo) three subadults resting on the road, one snarling, Central Kalahari Game Reserve, Botswana

Tony Heald / Giant Otter (Pteronura brasiliensis) adult with young in water, Pantanal, Brazil

Tony Heald / Black skimmer (Rynchops flavirostris) fishing by skimming along water surface, Pantanal, Brazil

Tony Heald / Bengal tiger (Panthera tigris tigris) walking, Bandhavgarh National Park, India.

Tony Heald / Junglefowl (Gallus gallus) male, Kaziranga National Park, Assam, India, March.

Tony Heald / Asian elephant (Elephas maximus) mother and baby domesticated elephants in water, Bandhavgarh National Park, India. March.

Tony Heald / Asian elephant (Elephas maximus) domesticated elephant working, picking reeds, Kaziranga National Park, Assam, India, March 2009.

Tony Heald / Hanuman langur (Semnopithecus entellus) baby next to mother, Bandhavgarh National Park, India.

Tony Heald / Hanuman langur (Semnopithecus entellus) eating coconut husk, Bandhavgarh National Park, India. March.

Tony Heald / Indian rhinoceros (Rhinoceros unicornis) mother and calf, rear view. Kaziranga National Park, Assam, India. Vulnerable species

Tui De Roy / Volcanic caldera - caldera lake steaming after eruption. Fernandina Island, Galapagos, Ecuador.

Tony Heald / Bateleur Eagle (Terathopius ecaudatus) female, stretching wings Kgalagadi Transfrontier Park, South Africa. January

Tony Heald / Black-backed Jackal (Canis mesomelas) drinking, Kgalagadi Transfrontier Park, South Africa. January

Tony Heald / African Wild Dog (Lycaon pictus) pack passing infront of large African elephant (Loxodonta africana) Mana Pools National Park, Zimbabwe October 2012

Tony Heald / Black faced Impala (Aepyceros melamis petersi) female jumping, Etosha National Park, Namibia

Tony Heald / Black faced Impala (Aepyceros melamis petersi) female jumping, Etosha National Park, Namibia

Tony Heald / African Lion (Panthera leo) young male at sunrise, Etosha National Park, Namibia

Sharon Heald / Common zebra (Equus quagga) foal in dusty sunset, Etosha National Park, Namibia Photo by Sharon Heald

Tony Heald / Black rhinoceros (Diceros bicornis) Etosha National Park, Namibia October

Tony Heald / Black rhinoceros (Diceros bicornis) male urine testing, flehmen reaction, Etosha National Park, Namibia October

Tony Heald / African elephant (Loxodonta africana) at sunset by water, Etosha National Park, Namibia October

Tony Heald / African lion (Panthera leo) young male backlit at sunrise, Etosha National Park, Namibia October

Tony Heald / Blue Crane (Anthropoides paradiseus) performing its dance display. Etosha National Park, Namibia, January.

Tony Heald / Red-Billed Teal (Anas erythrorhyncha) foraging in water. Etosha National Park, Namibia, January.

Tony Heald / Black-Winged Stilt (Himantopus himantopus) wading. Etosha National Park, Namibia, January.

Tony Heald / Eland (Taurotragus oryx) males locking horns and fighting. Devil's Thorn flowers (Tribulus terrestris) cover the ground. Etosha National Park, Namibia, January.

Tony Heald / Eland (Taurotragus oryx) male horning the ground which is covered in Devil's Thorn flowers (Tribulus terrestris). Etosha National Park, Namibia, January.

Tony Heald / Zebra (Equus quagga) foal peering over its mother's striped back. Monochrome. Etosha National Park, Namibia, January.

Tony Heald / Zebra (Equus quagga) foal running through Devil's Thorn flowers (Tribulus terrestris). Etosha National Park, Namibia, January.

Tony Heald / African Elephant (Loxodonta africana) male scenting with trunk raised. Etosha National Park, Namibia, January.

Tony Heald / Spotted Hyaena (Crocuta crocuta) rolling in Devil's Thorn flowers (Tribulus terrestris). Etosha National Park, Namibia, January.

Tony Heald / Black Rhinoceros (Diceros bicornis) charging. Etosha National Park, Namibia, January.

Tony Heald / Black Rhinoceros (Diceros bicornis) running. Etosha National Park, Namibia, January.

Sharon Heald / Black-faced Impala (Aepyceros melamis petersi) male standing in a field of Devil's Thorn flowers (Tribulus terrestris). Etosha National Park, Namibia, January.

Sharon Heald / African lion [Panthera leo] mother leading two very young cubs to water, Etosha National Park, Namibia, August

Tony Heald / White rhinoceros [Ceratotherium simum] at water, Etosha National Park, Namibia, August