When a species becomes extinct, it's gone for good: the last surviving member has died.
Earth is currently experiencing the worst wave of species die-offs -- a mass extinction of plants and animals -- since the dinosaurs 65 million years ago, according to the Center for Biological Diversity. Scientists say that nearly all of the thousands of currently threatened species -- mammals, birds, fish, reptiles, amphibians, plants and invertebrates -- are at risk because of human activities, including habitat loss, introduction of non-natives, and the effects of climate change.
This list is based on the priorities of the World Wildlife Fund, a conservation organization that focuses on protection of species that are critical to their larger environment, and the The IUCN's Redlist, a comprehensive inventory of the conservation status of species around the world.
Here are 30+ animals that are at risk of disappearing from the planet forever.
Pere David's
Deer
- Elaphurus davidianus
- Status: Extinct in the Wild
- Population: about 600
This semi-aquatic deer of China vanished around 1939 when the last wild one was shot and killed. The Pere David's Deer has been recovered from the edge of extinction after being reintroduced into captivity in China, according to the IUCN redlist. There are now four wild populations being established by escapees from a Nature Reserve during severe flooding in 1998, according to IUCN.
Scimitar-horned Oryx
- Oryx dammah
- Status: Extinct in the Wild
The myth of the one-horned unicorn may have originated from this antelope, which was once widespread across northern Africa and was domesticated in ancient Egypt. Overhunting and habitat loss, including competition with domestic livestock, are the main reasons for the extinction of the wild population, according to the IUCN Redlist.
Guam kingfisher
- Todiramphus cinnamominus
- Population: about 146
- Status: Extinct in the Wild
The Guam kingfisher is a species of kingfisher from the U.S. territory. The wild population was killed off by the non-native brown tree snake. It exists only in captivity. The male pictured here is at the Bronx Zoo.
Alagoas Curassow
- Mitu mitu
- Population: about 130
- Status: Extinct in the Wild
Clearance of the lowland forests of Brazil for sugarcane, as well as poaching, have brought this glossy-black, pheasant-like bird to the edge of extinction. While the bird exists in captive breeding programs, much of its wild habitat has been destroyed.
Guam Rail
- Hypotaenidia owstoni
- Population: about 150
- Status: Extinct in the Wild
The last individual in the wild of this flightless but fast-running bird died in 1987, killed by the brown tree snake. Captive breeding programs in Guam and the U.S. may restore the population. Pictured is a Guam Rail at the Cincinnati Zoo.
South China Tiger
- Panthera tigris amoyensis
- Status: Critically Endangered (possibly Extinct in the Wild)
- Population: 30-80
According to the World Wildlife Fund, the South China tiger population was about 4,000 in the early 1950s. In the next few decades, thousands were killed, hunted as a pest. Though the Chinese government banned hunting in 1979, by 1996 the population was estimated to be just 30-80 of these tigers. Today the big cat is considered to be "functionally extinct," as it has not been seen in the wild for more than 25 years.
Amur Leopard
- Panthera pardus orientalis
- Status: Critically Endangered
- Population: More than 84
A rare subspecies of leopard of the Russian Far East, the Amur leopard can run at speeds of up to 37 mph. It is frequently killed by poachers for its beautiful, spotted fur, according to WWF.
Black Rhino
- Diceros bicornis
- Status: Critically Endangered
- Population: 5,000 - 5,400
Killed in large numbers by European hunters and settlers, today rhinos are an important source of income from ecotourism in places like Namibia. World Wildlife Fund says this species has made a strong comeback from the brink of extinction, but poaching and black-market trafficking of rhino horn continues to threaten recovery. Pictured is a black rhinoceros in Kruger national park, South Africa.
Orangutan
- Pongo pygmaeus
- Status: Critically Endangered
- Population: About 104,700
Sumatran Orangutan
- Pongo abelii
- Status: Critically Endangered
- Population: 14,613
Highly intelligent, Orangutans share 96.4% of genes with humans. Female Orangutans are hunted most, and if caught with offspring, the young are often kept as pets.
Sumatran Orangutans live in the trees of tropical rainforests, and rarely travel on the ground.
Cross River Gorilla
- Gorilla gorilla diehli
- Status: Critically Endangered
- Population: 200 to 300 individuals
Cross River gorillas live in a region populated by many humans in Cameroon and Nigeria. As humans clear forests for timber, agriculture and livestock, the gorillas continue to lose habitat. They are also poached by hunters.
Eastern Lowland Gorilla
- Gorilla beringei graueri
- Status: Critically Endangered
- Population: Unknown-Possibly as few as 8,500
Poaching, disease, habitat destruction and years of civil unrest in the Democratic Republic of Congo have impacted the population of this gorilla.
Hawksbill Turtle
- Eretmochelys imbricata
- Status: Critically Endangered
- Population: n/a
Hawksbills feed in coral reefs, helping to maintain the health of reefs and sea grass beds. Their existence is threatened by wildlife trade of their shells, habitat loss, egg collection, pollution and development on coasts, where they lay their eggs. They often get caught on fishing hooks or tangled in gillnets, causing them to drown.
Javan Rhino
- Rhinoceros sondaicus
- Status: Critically Endangered
- Population: 58-68
With just 58-68 of these rhinos that live in Ujung Kulon National Park in Java, Indonesia, these are the most threatened of all rhinos. Most were killed by trophy hunters during colonial times. Vietnam's last Javan rhino was poached in 2010. They are killed for their horn, which is coveted in parts of Asia for its supposed medicinal qualities and as an ornament. Even in the park, poaching remains a threat.
Malayan Tiger
- Panthera tigris jacksoni
- Status: Critically Endangered
- Population: 250-340
This tiger is found only on the Malay Peninsula and in the southern tip of Thailand. It is threatened by loss of habitat to logging operations and road development, as well as illegal wildlife trade and sometimes angry villagers who retaliate for loss of livestock.
Mountain Gorilla
- Gorilla beringei beringei
- Status: Critically Endangered
- Population: 880
The remainder of these gorillas live in the Bwindi Impenetrable National Park in Uganda. These animals have endured years of war, hunting, habitat destruction and disease. Conservation efforts have helped increase the population, according to WWF.
Saola
- Pseudoryx nghetinhensis
- Status: Critically Endangered
- Population: Unknown
Often called the Asian unicorn, little is known about the rarely seen saola. None exist in captivity. They are found only in the Annamite Mountains of Vietnam and Laos. Scientists have documented saola in the wild on only four occasions.
Sumatran Elephant, Asian Elephant
Sumatran Elephant
(pictured)
- Elephas maximus sumatranus
- Status: Critically Endangered
- Population: 2,400 - 2,800
Asian Elephant
- Elephas maximus indicus
- Status: Endangered
- Population: Fewer than 50,000
Elephants are victims of deforestation and poachers who kill them and sell their tusks on the illegal ivory market. Elephant numbers have declined by 80% in less than 25 years, according to the World Wildlife Fund.
Sumatran Rhino
- Dicerorhinus sumatrensis
- Status: Critically Endangered
- Population: Fewer than 100
Much smaller than other rhinos, (they weigh up to 2,000 pounds, while other rhinos can weigh over 5,000 pounds) Sumatran rhinos are also known as the hairy rhinoceros for their long hair. Poaching for their horn has driven these animals to near extinction.
Sumatran Tiger
- Panthera tigris sumatrae
- Status: Critically Endangered
- Population: Less than 400
Habitat destruction from deforestation forces tigers into human-populated areas in search of food, where they are often killed by villagers. They are victims of illegal wildlife trade, prized for their bones and their pelts.
Vaquita
- Phocoena sinus
- Status: Critically Endangered
- Population: 30
The rarest marine mammal in the world is on the edge of extinction, and could be gone by this year, according to World Wildlife Fund. This relatively small porpoise lives in Mexico's Gulf of California, where they are often caught and drowned in gillnets used by illegal fishing operations in marine protected areas, despite efforts by Mexico to protect it. In August, a U.S. federal judge ordered a fishing embargo against Mexico to protect the vaquita, according to media reports.
Western Lowland Gorilla
Living in some of the most dense and remote rainforests in Africa, large numbers of these gorillas died from the deadly Ebola virus. They are also killed for bushmeat or during the capture of their babies for pets. Populations still exist in isolated parts of the Republic of Congo. Pictured is a gorilla at the Prague zoo.
Yangtze Finless Porpoise
- Neophocaena asiaeorientalis ssp. asiaeorientalis
- Status: Critically Endangered
- Population: 1,000-1,800
This highly intelligent porpoise lives in China's Yangtze River, the longest river in Asia. Their decline is caused by overfishing, which decreases their food supply, as well as pollution and ship movement. Above, in Jiangxi, China, Poyang Lake, the largest freshwater lake in China, and fed by the Yangtze, shrunk due to drought. Reconnecting floodplain lakes helps restore seasonal flows and allows the migration of species like the finless porpoise, according to WWF.
African Wild Dog
- Lycaon pictus
- Status: Endangered
- Population: 6,600
World Wildlife Fund calls the African Wild Dog one of the world's most endangered mammals. The largest populations are in southern Africa, Tanzania, and northern Mozambique. They are often killed by humans, accidentally and intentionally, as well as viral diseases like rabies and distemper. Habitat loss and competition with larger predators like lions is also a threat.
Amur Tiger
- Panthera tigris altaica
- Status: Endangered
- Population: As many as 540
Bengal Tiger
- Panthera tigris tigris
- Status: Endangered
- Population: more than 2,500
Also known as the Siberian tiger, the Amur tiger was driven to the brink of extinction in the 1940s with no more than 40 left in the wild. Bengal tigers are found mainly in India, with smaller populations in Bangladesh, Nepal, Bhutan, China and Myanmar. Tigers are threatened by habitat loss, illegal wildlife trade, and conflict with humans.
Humphead Wrasse
- Cheilinus undulatus
- Status: Endangered
- Population: N/A
This huge fish is important to the health of the coral reefs where it lives. These fish can be over 6 feet long and live 30 years. Habitat loss and illegal fishing threatens the existence of the humphead wrasse, which is considered a delicacy in Southeast Asia, one of the most expensive live reef fishes in the world. Pictured is a humphead wrasse in an aquarium in Japan.
Black-footed Ferret
- Mustela nigripes
- Status: Endangered
- Population: Approximately 370 in the wild
This little ferret is one of the most endangered mammals in North America. It was once thought to be globally extinct. It continues to be threatened by habitat loss and disease. The ferret feeds on prairie dogs. State and federal agencies, zoos, Native American tribes, conservation organizations and landowners have given black-footed ferrets a second chance for survival, the World Wildlife Fund says.
Blue Whale
- Balaenoptera musculus
- Status: Endangered
- Population: 10,000-25,000
Blue whales are harmed by ship strikes and fishing gear. Climate change has had an impact on krill, their food supply. The largest animal in the world (they can weigh up to 200 tons) blue whales are at the top of the food chain and important to the health of the marine environment.
Bluefin Tuna
- Thunnus spp
Populations of Bluefin tuna, a highly sought-after delicacy for sushi and sashimi, are harmed by overfishing and illegal fishing. According to the Center for Biological Diversity, the bluefin has been overfished to less than 3% of its historic population
Bonobo
- Pan paniscus
- Status: Endangered
- Population: 10,000 to 50,000
Similar to chimpanzees, Bonobos are smaller, leaner and darker. They live in forests south of the Congo River in the Democratic Republic of Congo. Civil unrest, poaching, and habitat loss threaten these primates.
Borneo Pygmy Elephant
- Elephas maximus borneensis
- Status: Endangered
- Population: Approximately 1,500
This baby-faced subspecies of Asian elephant inhabits northeastern Borneo, in Indonesia and Malaysia. They are actually not much smaller than other Asian elephants, but they tend to be more gentle-natured. The species is threatened by loss of habitat to oil palm plantations.
Galapagos Penguin
- Spheniscus mendiculus
- Status: Endangered
- Population: fewer than 2,000
This is the only penguin species found north of the equator and in the Galapagos. Their population is threatened by pollution, bycatch and climate change.
Red Panda
- Ailurus fulgens
- Status: Endangered
- Population: less than 10,000
Red pandas live in the Eastern Himalayas. Slightly larger than a house cat, they are poached for their pelts. Much of their forest habitat is being cleared, and they are often killed when they get caught in traps meant for other animals.
