Below are the causes that make them endangered :
Tarsius-siau :
- Tarsiers live in a colony, if separated from their colony, they will die
- Tarsiers often stress
- These animals also often roam at residents. When people find tarsiers, it will be captured to be maintained. Because it was not in the original habitat, they will die.
- And the worst, is tarsiers often consumed by the people because their meat are delicious.
Javan Slow Loris :
- Slow lorises often found in illegal markets for trade.
- In addition, they frequently hunted. So, the population gradually became less
Pongo Abelii:
- These animals often captured and maintained by people.
- High death rate is not matched by the number of their birth.
- Orangutans often die by various causes such as lost their habitat by illegal logging, but it was hard to bear due to orang-utans give birth only 2 children each year
Simias Concolor :
- A result of hunting by local people as a source of protein for local communities
- According to the observations of experts, Simakobus always wanted to see the form of threats, so do not run away when they saw people, and the cause is easy once hunted animals
- Generally, primates are often hunted will be more "alert" to see human beings, but it does not happen with Simakobu. Consequently, Simakobu population dropped dramatically. We easily find Simakobu skull on display in the huts of indigenous forest.