Ingo Arndt / Ostrich (Struthio camelus) female chasing away rival, Masai Mara National Reserve, Kenya

Ingo Arndt / African Lion (Panthera leo) juveniles play fighting, Masai Mara National Reserve, Kenya

Ingo Arndt / African Lion (Panthera leo) juveniles play fighting, Masai Mara National Reserve, Kenya

Ingo Arndt / African Lion (Panthera leo) male portrait, Masai Mara National Reserve, Kenya

Ingo Arndt / African Lion (Panthera leo) female, Masai Mara National Reserve, Kenya

Ingo Arndt / African Jacana (Actophilornis africana) foraging near Hippopotamus (Hippopotamus amphibius) amid water lettuce, Masai Mara National Reserve, Kenya

Ingo Arndt / Alpine Marmot (Marmota marmota) calling, Austria

Ingo Arndt / Alpine Marmot (Marmota marmota) yawning, Austria

Ingo Arndt / African Lion (Panthera leo) male, Masai Mara National Reserve, Kenya

Ingo Arndt / White Rhinoceros (Ceratotherium simum) mother and juvenile, Lake Nakuru, Kenya

Ingo Arndt / White Rhinoceros (Ceratotherium simum) males facing off, Lake Nakuru, Kenya

Ingo Arndt / Monarch (Danaus plexippus) butterfly feeding on nectar of Goldenrod during migration, East Coast, USA

Ingo Arndt / Monarch (Danaus plexippus) butterflies gathering to drink water and take up minerals, Michoacan, Mexico

Ingo Arndt / Emperor Scorpion (Pandinus imperator) photographed under ultraviolet light, Africa

Ingo Arndt / Blue Morpho (Morpho peleides) butterfly wing with false eyespots, Costa Rica

Ingo Arndt / Blue Morpho (Morpho peleides) caterpillar hatching out of egg, Costa Rica

Ingo Arndt / Blue Morpho (Morpho peleides) caterpillar hatching out of egg, Costa Rica

Ingo Arndt / Blue Morpho (Morpho peleides) butterfly egg, Costa Rica

Ingo Arndt / The American Falls at Niagara Falls, New York

Ingo Arndt / Researcher Jim Lewis curator of the true bug collection at INBio, San Jose, Costa Rica

Ingo Arndt / Water Boatman (Notonecta glauca) with reflection underwater, a true bug of the Heteroptera suborder, Europe

Ingo Arndt / Pond Skater (Gerris sp) using surface tension to walk on water, a true bug of the Heteroptera suborder, Europe

Ingo Arndt / Two scientists from the Alfred-Wegener Institute, collecting tide pool samples, North sea, Helogland, Germany

Ingo Arndt / Brown-throated Three-toed Sloth (Bradypus variegatus) hanging in tree, Amazon, Peru

Ingo Arndt / Black-handed Spider Monkey (Ateles geoffroyi) hanging by its prehensil tail in forest canopy, Santa Rosa National Park, Costa Rica

Ingo Arndt / Scarlet Macaw (Ara macao) close up, portrait, Amazon ecosystem, Peru

Ingo Arndt / Scarlet Macaw (Ara macao) close up, portrait, Amazon ecosystem, Peru

Ingo Arndt / Blue and Yellow Macaw (Ara ararauna) eating fruit, Amazon ecosystem, Peru

Ingo Arndt / Chimpanzee (Pan troglodytes) juvenile fishing for termites, endangered, Gombe Stream National Park, Tanzania

Ingo Arndt / European River Otter (Lutra lutra) sisters resting, Europe

Ingo Arndt / European River Otter (Lutra lutra) sisters resting, Europe

Ingo Arndt / Eastern Grey Kangaroo (Macropus giganteus) joey reaching into mother's pouch, Wilson's Promontory National Park, Australia

Ingo Arndt / Gelada Baboon (Theropithecus gelada) male, yawning, Simien Mountains, Ethiopia

Ingo Arndt / Alpine Marmot (Marmota marmota) showing sharp teeth while calling, Hohe Tauern National Park, Austria

Ingo Arndt / Emperor Penguin (Aptenodytes forsteri) four walking in a line, Weddell Sea, Antarctica

Ingo Arndt / Leopard Seal (Hydrurga leptonyx) barking, Weddell Sea, Antarctica

Ingo Arndt / Mikeno Volcano (3634 meters) with lenticular cloud, Republic of the Congo in the Virunga heartland, view from Rwanda

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) juvenile, Parc National Des Volcans, Rwanda

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) baby, Parc National Des Volcans, Rwanda

Ingo Arndt / Mountain Gorilla (Gorilla gorilla beringei) Susa group showing male silverback, two females and two juveniles, Parc National Des Volcans, Rwanda

Ingo Arndt / Antarctic Krill (Euphausia superba) with yellow algae in stomach, a small shrimp-like crustacean is the most important zooplankton in the Antarctic food web, Weddell Sea, Antarctica

Ingo Arndt / Ctenophore (Beroe cucumis) showing typical symmetrical combs made of cilia, Weddell Sea, Antarctica

Ingo Arndt / Hydromedusae (Calycopsis borchgrewinki) with extended tentacles, Weddell Sea, Antarctica

Ingo Arndt / Emperor Penguin (Aptenodytes forsteri) pair courting, Weddell Sea, Antarctica

Ingo Arndt / Edible Frog (Rana esculenta) with reflection, Germany

Ingo Arndt / Rafflesia (Rafflesia arnoldii) flower, is the largest flower in the world, fresh open first day, highlands, Malaysian Peninsula

Ingo Arndt / Magellanic Penguin (Spheniscus magellanicus) couple, Seno Otway, Patagonia, Chile

Ingo Arndt / Cheetah (Acinonyx jubatus) yawning, Namibia