A small patch of land situated along the winding Sungai Liang is home to the Gibbon Conservation Society, an NGO focused on rehabilitating gibbons that were previously kept as pets. Its aim is to one day return these gibbons to the wild.

At the heart of the NGO is Mariani Ramli, fondly known as Bam among her friends, who has devoted her life to “re-wilding” these gibbons and ensuring they may one day thrive and sing in their natural habitat.

“The rehabilitation project is a project that you need to dedicate your life to because it takes a minimum of five years if you’re lucky, and up to 10 to 15 years for one individual gibbon to be released back into the wild.

“Gibbons are apes. Like us humans, they depend on their parents to learn things and when you take them away from their parents, rehabilitation needs to replace the role of the parents,” Mariani told FMT.

Malaysia is home to five species of gibbons – the siamang, lar gibbon, agile gibbon, North Bornean gibbon, and Abbot’s gibbon. All are categorised as “endangered” under the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species.

Gibbons are arboreal creatures, meaning they live above ground in trees. They are among the fastest primates in the world, being able to reach speeds of up to 56kph when swinging from branches.

But perhaps the most unique trait of gibbons is their singing, which is done to mark their territory and find their mates.

Gibbons are considered a “totally protected” species but remain under threat from poachers and traders looking to make a quick buck.

Social media platforms like Facebook, Instagram and TikTok have become a popular marketplace for the sale of the primates as pets, with a single gibbon fetching from RM2,000 to RM4,000. Brown-furred gibbons, considered rare, will fetch a higher price.

Mariani said poachers and traders would usually target juvenile gibbons and kill their parents and entire family in the process of capturing them in the wild.

These juvenile gibbons are then sold as pets and raised in captivity and as a result, they tend to develop human-like behaviour.

They later develop a mental disorder known as “zoochosis”, which manifests in stereotypic behaviour such as frequent pacing, rocking and nail-picking.

Ebony, a female gibbon that was surrendered to the society at eight months old, would rock herself back and forth after her owners kept her in a small basket for prolonged periods in order to “discipline” her.

The gibbons taken in by Mariani and her team will first undergo a behavioural assessment consisting of seven criteria, which will then determine the areas of focus for their rehabilitation.

Among the criteria for each gibbon are the ability to brachiate within the enclosure, spending no more than about 5% of their time on the ground daily, and being able to regularly sing in a duet with another gibbon.

Once the seven criteria are met, the gibbons are then released into the wild and will continuously be monitored for a further 24 months.

Mariani said a sign that the rehabilitation has been successful is when the gibbons start producing offspring, as this shows that they feel safe and comfortable in the wild.

A male gibbon, named Coley, was kept in a tiny cage as a pet, stunting his growth. He was not able to use his limbs to brachiate due to weak muscles when he first arrived at the centre.

However, he has progressed well in his rehabilitation and has even found love in Ebony. The pair, now life-long mates, are set to be released into the wild in the coming year.

They will sing their song in the lush green forests of Pahang and remind Mariani of the value of her work.