The number of Javan rhinos, which were once common throughout south-east Asia, has dropped dramatically as a result of hunting and habitat destruction.
2. Mountain Gorillas
A subspecies of the eastern gorilla known as the mountain gorilla, it is only found in two isolated populations in the high-altitude forests of the volcanic mountains of the Democratic Republic of the Congo, Rwanda, and Uganda.
3. Amur Leopard
With only about 100 remaining in the wild, the Amur leopard is one of the most endangered big cats in the world.
4. Sunda Island Tiger
The Sunda Island tiger is the world's smallest tiger subspecies and can weigh up to 140 kilograms. There are estimated to be around 600 in the wild, and are only found on the Indonesian island of Sumatra.
5. Tapanuli Orangutan
With only about 100 remaining in the wild, the Amur leopard is one of the most endangered big cats in the world.
6. Black Rhinos
Large-scale poaching caused substantial population declines in black rhinos between 1960 and 1995. 2% or so managed to withstand the brutal assault in the past.
7. Yangtze Finless Porpoise
Being the only live freshwater porpoise in existence makes the Yangtze Finless Porpoise unique within its family.
8. Hawksbill Turtles
Since sea turtles are the actual ocean wanderers, it is challenging to estimate their true population numbers, however it is estimated that there are between 20,000 and 23,000 nesting turtles.
9. Sumatran Orangutan
Only the Indonesian island of Sumatra is home to the Sumatran orangutan. There are currently less than 14,000 of them in the wild, and the IUCN has classed them as severely endangered.
10. African Forest Elephant
One of the two members of the African elephant species, the secretive forest elephant, can be found deep within the thick, humid woods of West and Central Africa.