Editor’s note: Today, Oct. 24, is International Gibbon Day. In this piece, Conservation International’s Anton Ario examines the plight of an increasingly rare species of gibbon amid efforts to save it from extinction.
If a male Javan gibbon were a person, you could call him a “family man.”
These small apes — also known as silvery gibbons — are family-oriented, bonding for life with one mate and creating close-knit family units. Extremely territorial, each family inhabits a fiercely guarded 15-to-20-hectare (37-to-50-acre) area of tropical forest as its own.
As their name suggests, these apes are found exclusively on the Indonesian island of Java — the most populous island on the planet.
And there lies the problem.
Java’s remaining forests face continuous pressure from development that chips away at the gibbons’ habitat. Additionally, gibbons are highly sought as pets, and trappers capture the animals — usually when they are still babies — to be sold illegally at markets across Indonesia.
We know that because of gibbons’ strong family bonds, the loss of a member can cause immense stress to the animals.
It’s also causing their numbers to shrink.
The population of Javan gibbons now stands at about 4,000 to 5,000 individual adults in the wild, according to the International Union for Conservation of Nature (IUCN), which classifies the species as critically endangered. This is particularly regrettable because the gibbons play an important role in the health of the forest, spreading seeds from the forest fruits they eat.
Efforts are well underway to protect this species. The Javan Gibbon Foundation (Yayasan Owa Jawa, in Indonesian) and Mount Gede Pangrango National Park operate the Javan Gibbon Rescue and Rehabilitation Program. The partnership, supported by Conservation International, the University of Indonesia and the Silvery Gibbon Project, rescues pet or seized Javan gibbons to be rehabilitated and released into their natural habitat.
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Indonesia is taking the issue seriously, and Javan gibbons have long been a protected species in the Southeast Asian country.
But rehabbing the gibbons is not easy.
“A Javan gibbon that has been captured and kept as a pet loses its instinct to survive [in the wild],” says Pristiani Nurantika, a Javan gibbon researcher and veterinarian. “So we’re trying to restore that instinct — otherwise, they’ll die if we release them in their current state.”
Before release, the gibbons must form a family unit — a difficult prospect, as gibbons are highly selective. But without a family, a gibbon is vulnerable and does not have a clan to help protect it in the wild.
To date, 16 Javan gibbons have been released into the wild since 2009. To commemorate International Gibbon Day, two more families of gibbons are planned to be released in Java today.
It’s a small but critical step in ensuring these spectacular species can endure.
“Releasing Javan gibbons [back] into their natural habitat isn’t an easy task,” says Wahyudi Wardoyo, chairman of the advisory board of Yayasan Owa Jawa. “We need to have all the support we can get from different stakeholders to save these primates from extinction.”
Anton Ario is West Java program manager for CI-Indonesia.