The pairs mate for life and raise their families in the forest. Periodically they sing from their homes to communicate with each other and other families, and have been doing so for thousands of years.
But these are not people, they are Javan gibbons (Hylobates moloch) and their songs may not grace these forests much longer if we don’t act now. In fact, human beings are both the biggest threat to the Javan gibbons and their last chance.
In Java, Even Restricted Areas Not Safe
The island of Java is slightly larger than the state of New York and in the last 40 years, the human population of the island has doubled. Increased pressure for natural resources has had an impact: the gibbon population on Java is down to a startling 4,000. The numbers are so low that the IUCN has listed the Javan gibbon as Endangered.
Gibbon populations in Java are largely restricted to protected areas and national parks, where what little of the original Javan rainforest remains.
But they are not safe there either. Hunters and poachers still pursue them, and small-scale subsistence use of the forests for charcoal and homes are also threats.
Primates such as gibbons serve a vital role in forest ecosystems as they disperse seeds throughout the forest. The remaining forests where gibbons live are in danger of becoming less diverse and less robust if gibbons disappear forever.
LEARN MORE: Test your primate knowledge and visit our Interactive Primate Tree.
So scientists are trying everything imaginable to stop the loss of more gibbons while using tactics such as captive breeding to reintroduce new gibbons into the wild.
CI’s Dr. Jatna Supriatna is on the front-lines in Java helping to protect and increase gibbon numbers while raising the profile of their plight internationally.
Supriatna, a renowned primatologist, has worked with numerous partners such as the University of Indonesia, the Alami Foundation and Nagao Environmental Fund Japan to mobilize field-based conservation programs.
In the Field
One such effort Supriatna has led is the creation of the Javan Gibbon Rescue and Rehabilitation Center.
The goal is to take gibbons that are rescued or confiscated as part of the illegal wildlife trade and rehabilitate and reintroduce them into the wild. But the effort is just getting off the ground and getting captive gibbons to mate is challenging work.
Gibbons’ monogamy involves long courtships and the risk of having one reject the other is quite high. But that is not slowing down the efforts of the many diverse groups in Java and around the world teaming up to save the last of the gibbons and the last of the Javan forests.
READ MORE: Javan Gibbons are not the only primates being threatened.