The Sumatran tiger (Panthera tigris sumatrae) is a critically endangered species, threatened by habitat loss and poaching.
Photograph by Steve Winter, Nat Geo Image CollectionA remotely operated camera captured these lionesses resting on a kopje, a rocky outcrop in Serengeti National Park, Tanzania.
Photograph by Michael Nichols, Nat Geo Image CollectionAn elephant group on the move in Samburu National Park, Kenya.
Photograph by Michael Nichols, Nat Geo Image CollectionMale giraffes pursuing a female in estrus at Etosha National Park, Namibia.
Photograph by Frans Lanting, Nat Geo Image CollectionPortrait of a resting but alert leopard (Panthera pardus) on Chiefs Island, in Botswana's Okavango Delta.
Photograph by Beverly Joubert, Nat Geo Image CollectionA giant panda plays in the treetops inside an enclosure at the Wolong Giant Panda Research Centre, China.
Photograph by , Ami Vitale, Nat Geo Image CollectionCheetah cubs at play in Serengeti National Park, Tanzania.
Photograph by Frans Lanting, Nat Geo Image CollectionA Polar bear mother and her cub on the move in Hudson Bay, Canada.
Photograph by Frans Lanting, Nat Geo Image CollectionA gray wolf (Canis lupus) in the snow. Wolves are the only species among the top 10 most charismatic animals that are not globally threatened.
Photograph by Joël Sartore, Nat Geo Image CollectionMountain gorillas rest on high-elevation slopes of Mount Karisimbi, Rwanda.
Photograph by Ronan Donovan, Nat Geo Image CollectionA young chimpanzee peeks through the leaves in Taï National Park, in Côte d’Ivoire.
Photograph by Michael Nichols, Nat Geo Image CollectionAn aerial view of plains zebras (Equus quagga) walking in a flood plain in Okavango Delta, Botswana.
Photograph by Sérgio Pitamitz, Nat Geo Image CollectionA Nile Hippopotamus surfaces at the edge of a reed bed, in Chobe National Park, Botswana.
Photograph by Jason Edwards, Nat Geo Image CollectionA great white shark swims in waters off the Neptune Islands.
Photograph by Brian J. Skerry, Nat Geo Image CollectionA submerged American crocodile (Crocodiles acutus) lives in the dense mangroves within Cuba's Gardens of the Queen National Marine Park.
Photograph by Jennifer Hayes, Nat Geo Image CollectionAtlantic spotted dolphins swim in the waters off Bimini in the Bahamas.
Photograph by Brian J. Skerry, Nat Geo Image CollectionWhite rhinoceroses (Diceros bicornis) in Kenya's Lewa Wildlife Conservancy.
Photograph by Frans Lanting, Nat Geo Image CollectionA grizzly bear fishes for salmon in the Fishing Branch River in Yukon Territory, Canada.
Photograph by Paul Nicklen, Nat Geo Image CollectionPortrait of a Victorian koala (Phascolarctos cinereus) in Australia.
Photograph by Doug Gimesy, Nat Geo Image CollectionAn endangered blue whale with unique colour patterns and markings, off Costa Rica.
Photograph by Flip Nicklin, Nat Geo Image Collection