Ernie Janes / RF- Silhouette of Red deer (Cervus elaphus) stag and hind by tree at sunset, Norfolk, UK. (This image may be licensed either as rights managed or royalty free.)

Ernie Janes / RF- Domestic pig, hybrid large white sow and piglets in sty, UK, September 2010. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Red Deer (Cervus elaphus) stag and three does silhouette grazing. Dyrehaven, Denmark. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Hippopotamus (Hippopotamus amphibius) surrounded by water lettuce. Kruger National Park, South Africa. (This image may be licensed either as rights managed or royalty free.)

Denis-Huot / RF- South african giraffe (Giraffa camelopardalis giraffa) drinking. Etosha National Park, Namibia. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Hippopotamus (Hippopotamus amphibius) coming to end of a yawn whilst in river. Mana Pools National Park, Zimbabwe. October 2012. (This image may be licensed either as rights managed or royalty fre...

Nick Garbutt / RF- Lone American Bison (Bison bison) grazing in snow. Hayden Valley, Yellowstone National Park, Wyoming, USA, February. Digital composite. (This image may be licensed either as rights managed or roya...

Ernie Janes / RF- Domestic sheep, ewe and lambs in pen, UK. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Black faced Impala (Aepyceros melamis petersi) female jumping, Etosha National Park, Namibia. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Hippopotamus (Hippopotamus amphibius) captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Rothschild's giraffe (Giraffa camelopardalis rothschildi) two curious giraffes looking down, captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Rothschild's giraffe (Giraffa camelopardalis rothschildi) head and neck portrait, captive. (This image may be licensed either as rights managed or royalty free.)

Ernie Janes / RF- Domestic pig (Sus scrofa domestica) three piglets, Norfolk, UK. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / 2020VISION / RF- Head portrait of Red deer (Cervus elaphus) stag portrait, Cairngorms National Park, Scotland, UK, February. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / 2020VISION / RF- Wild boar (Sus scrofa) female. Forest of Dean, Gloucestershire, UK, March. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / 2020VISION / RF- Wild boar (Sus scrofa) inquisitive piglet. Forest of Dean, Gloucestershire, UK, March. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / 2020VISION / RF- Red deer (Cervus elaphus) stag in pine forest in snow blizzard. Alvie Estate, Cairngorms NP, Highlands, Scotland, UK, March. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Warthog (Phacochoeros aethiopicus) male wallowing in mud. Etosha National Park, Namibia, January. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF0 Springbok (Antidorcas marsupialis) lamb hidden in grass. Etosha National Park, Namibia, January. (This image may be licensed either as rights managed or royalty free.)

Ernie Janes / RF- Free range Domestic pig (Sus scrofa domesticus) waiting for feed, UK, August 2010. (This image may be licensed either as rights managed or royalty free.)

Alex Mustard / RF- Domestic pig (Sus domestica) swimming in sea. Exuma Cays, Bahamas. Tropical West Atlantic Ocean. This family of pigs live on this beach in the Bahamas and enjoy swimming in the sea. (This image ma...

Staffan Widstrand / RF- Arabian oryx (Oryx leucoryx) males fighting with locked horns, Dubai Desert Conservation area, United Arab Emirates. February. (This image may be licensed either as rights managed or royalty free....

Peter Cairns / RF- Red deer (Cervus elaphus) stag, Alladale Wilderness Reserve, Ardgay, Scotland, February. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Four Masai giraffes (Giraffa camelopardalis tippelskirchi) silhouetted on plains at sunset, Masai Mara, Kenya. (This image may be licensed either as rights managed or royalty free.)

Wild Wonders of Europe / Widstrand / RF- Male Spanish ibex (Capra pyrenaica) on rocks, Sierra de Gredos, Spain. November. (This image may be licensed either as rights managed or royalty free.)

Wild Wonders of Europe / Widstrand / RF- Spanish ibex (Capra pyrenaica) scenting tongue with air, Sierra de Gredos, Spain. November. (This image may be licensed either as rights managed or royalty free.)

Wild Wonders of Europe / Widstrand / RF- Female Spanish ibex (Capra pyrenaica) crossing rocks, Sierra de Gredos, Spain. November. (This image may be licensed either as rights managed or royalty free.)

Wild Wonders of Europe / Cairns / RF- Reindeer (Rangifer tarandus) portrait, semi-domesticated, small scale herding by local Sami, Sarek National Park, Laponia World Heritage Site, Lapland, Sweden. September 2008. (This image may be l...

Edwin Giesbers / RF- Hippopotamus (Hippopotamus amphibius) mother and baby, Queen Elizabeth National Park, Uganda. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Male Giraffes (Giraffa camelopardalis) sparring or necking, Etosha National Park, Namibia. January. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Hippopotamus (Hippopotamus amphibius) aggressive threat display. Katavi National Park, Tanzania. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Hippopotamus (Hippopotamus amphibius) threat display, South Luangwa National Park, Zambia. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Red deer (Cervus elaphus) stag portrait, during rut, Scotland, UK. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Roe deer (Capreolus capreolus) buck chasing female during rut, Wiltshire, UK. (This image may be licensed either as rights managed or royalty free.)

Andy Rouse / RF- Red deer (Cervus elaphus) stag in rut, Richmond Park, London, UK. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Red deer (Cervus elaphus) stag running during rut, Dyrehaven, Denmark. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Mountain Goat (Oreamnos americanus) adult shedding winter coat. Mount Reynolds, Glacier National Park, Montana, USA. July. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- White-tailed Deer (Odocoileus virginianus) two young fawns. Texas, USA. June. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Hippopotamus (Hippopotamus amphibius), Moremi Wildlife Reserve, Botswana. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Two Hippopotamus (Hippopotamus amphibius) play fighting, Chobe National Park, Botswana. (This image may be licensed either as rights managed or royalty free.)

Gabriel Rojo / RF- Hippotamus (Hippopotamus amphibius) submerged in waterhole, Kruger National Park, South Africa. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / RF- Red deer (Cervus elaphus) stag, standing on open hillside. Alladale Wilderness Reserve, Highlands, Scotland, UK. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / RF- Muskox (Ovibos moschatus) two juveniles on tundra, autumn, Dovrefjell National Park, Norway. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Male Waterbuck head portrait (Kobus ellipsiprymnus) Mana Pools National Park, Zimbabwe. (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF- Male Eastern white bearded wildebeest (Connochaetes taurinus albojubatus) sparring head to head. Serengeti National Park, Tanzania. (This image may be licensed either as rights managed or royalty...

Nick Garbutt / RF- White-bearded Wildebeest (Connochaetes taurinus albojubatus) Serengeti National Park, Tanzania. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Blue Wildebeest (Connochaetes taurinus) calf running with herd, Etosha national park, Namibia. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Caribou herd (Rangifer tarandus) grazing on tundra. Kobuk Valley National Park, Alaska, USA. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Reticulated giraffe (Giraffa cameloparalis reticulata) juveniles showing colour variation. Laikipia, Kenya. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / RF- Bison (Bison bison) mother with two calves in summer meadow. Yellowstone National Park, Wyoming, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Elk (Cervus elaphus) bull in rut crossing river while calling / bugling. Yellowstone National Park, Wyoming, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Bison (Bison bison) in Yellowstone National Park, Wyoming, USA, (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Moose bull grazing (Alces alces) head pportrait. Sarek National Park, Sweden. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / RF- Red deer (Cervus elaphus) stag silhouetted at dusk, Cairngorms National Park, Scotland. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Reindeer herd (Rangifer tarandus). Finnmarksvidda, Lapland, Norway. (This image may be licensed either as rights managed or royalty free.)

Tony Heald / RF- Giraffe (Giraffa camelopardalis) at end of rainbow. Etosha National Park, Namibia. (This image may be licensed either as rights managed or royalty free.)

Peter Cairns / RF- Young Bison (Bison bison) getting warmth from steaming geyser. Yellowstone, USA. (This image may be licensed either as rights managed or royalty free.)