The World Wildlife Fund (WWF) has updated its list of species most in danger of going extinct, with 19 animals now listed as "critically endangered", including gorillas, tigers, rhinos and orangutans.

Included on the list is the South China tiger, a subspecies of the predator which hasn't been spotted in the wild for more than 25 years, and is considered by scientists to be "functionally extinct". The list was revealed by Metro.

Four species of gorilla are on the list: the cross river gorilla, of which there are said to be just 200 to 300 left in the wild, mostly found in the Congo Basin.

There's also the eastern lowland gorilla, the largest of the list's four species.

There are just 880 mountain gorillas left on the planet, living in high-altitude environments under threat - like many on the list - from humans.

The number of western lowland gorillas in the wild is also unknown, because they occupy dense rainforest areas in Africa.

Poaching and disease have caused their numbers to dwindle by around 60%, but even if those threats were eliminated, the population would still require at least 75 years to recover.

There are three species of tiger on the list, including Malayan tiger of which there are just 250 to 340 left in the wild. There's also the aforementioned South China tiger and the Sumatran tiger, one of numerous Sumatran species on the list.

Sumatra is is a large island in western Indonesia, where subspecies of elephants, orangutans and rhinos are also at risk.

WWF Endangered Animals
The Sumatran elephant, South China tiger and orangutan. Getty Images

The black rhino is one of the more well-known species on the list. They are found in parts of Namibia and there are just 5,000 left in the wild, according to the WWF. The javan rhino are found only in the Ujang Kulon National Park in Indonesia, and there are just 58 to 68 left in the world.

By comparison, there are plenty of Bornean orangutan left in the word but even with a little over 100,000 they're still in danger thanks to rapidly declining numbers. Over the last 50 years the number of them has fallen by more than 50%.

Among the rest of the species of the list, there are three aquatic animals. Nobody is sure how many Hawksbill sea turtles still exist, but they're still considered to be in danger as they occupy coral reefs that are also under threat.

The Yangtze finless porpoise lives along the Yangtze River in Asia. Just 1,000 to 1,800 remain. There's also the Vaquita, which holds the unfortunate title of being the world's rarest marine mammal. It's believed there are just 30 left.

Below is the complete list, including the two species we've yet to mention: the Amur leopard and the saola.

  1. Amur leopard
  2. Black rhino
  3. Bornean orangutan
  4. Cross river gorilla
  5. Eastern lowland gorilla
  6. Hawksbill turtle
  7. Javan rhino
  8. Malayan tiger
  9. Mountain gorilla
  10. Orangutan
  11. Saola
  12. South China tiger
  13. Sumatran elephant
  14. Sumatran orangutan
  15. Sumatran rhino
  16. Sumatran tiger
  17. Vaquita
  18. Western lowland gorilla
  19. Yangtze finless porpoise