Fate of Vietnam’s Gibbons Hangs in the Balance

Even after years of researching gibbons in Southeast Asia, I have been shocked to uncover the pace at which Vietnam’s gibbons are barreling toward extinction. According to a recent review that I co-authored with colleagues at Fauna & Flora International, of the six species of crested gibbons that exist in Vietnam, five should be listed as Critically Endangered and one as Endangered at the national level.

“The Conservation Status of Gibbons in Vietnam” is a thorough review of the status of all of Vietnam’s gibbons and trends over the last 10 years, identifying the extent of the issues and where conservation effort needs to be invested. The findings: All species of gibbons in Vietnam have suffered from huge population losses in recent decades, and these declines do not appear to be slowing.

Vietnam’s gibbons are now largely restricted to the country’s protected area network; we found confirmed or provisional records from over 40 of the country’s 164 protected areas. However, even in these legally protected areas — and despite gibbons’ protected status — populations are slipping away.

During this study, we documented the local extinction of gibbons in seven areas in Vietnam in the last decade. As we classified local extinctions only in areas where we have sufficient data to be sure gibbons have disappeared, it’s likely that other areas have also lost their resident gibbons.

Dealing with the crisis that gibbons face in Vietnam is problematic. While the framework is in place, there are so many factors conspiring to continue this slow creep toward extinction: loss of forested habitats to agriculture, industry and infrastructure; habitat degradations from illegal logging; and hunting for use in traditional medicine and the pet trade.

Recent research by graduate student Caroline Waldrop and supported by CI shows just how easy it is to push small gibbon populations to extinction. Gibbons take a long time to mature (females may not breed until the age of eight) and only breed once every three or four years. As a result, the regular loss of only a few individuals from small populations is enough to finish them off, although this can take decades to be realized. It is likely that there are existing populations in Vietnam that are already functionally extinct — they just don’t know it yet.

Our recent status review identifies key locations for conservation investment for each species. Unfortunately, as the funding and political will is lacking to protect all existing gibbon populations, we need to adopt a triage approach.

In order to effectively protect and restore gibbon populations, a shift in behavior is required. A shift towards greater accountability for protected areas to manage the wildlife that they house. A shift in cultural attitudes that push the purported health benefits of wildlife consumption. And a shift towards greater investment in species conservation so that under-staffed, under-resourced and under-skilled conservation practitioners can do a better job.

Many people might ask: “Do we really need gibbons?” At CI we talk a lot about ecosystem services — the benefits that intact, functioning ecosystems provide. In their role as seed dispersers, gibbons are an important piece in that puzzle. These apes are largely frugivorous and they often swallow seeds whole, which travel through their guts and are then distributed around the forest, helping to maintain and regenerate healthy forests. We are currently supporting the Ph.D. research of Jackson Frechette in Cambodia’s Veun Sai-Siem Pang Conservation Area to determine exactly how significant this role is.

Ecosystem services aside, it is hard not to see the intrinsic value that gibbons have. Their haunting morning calls, the way they quietly materialize out of the forest on swinging arms and their gentle demeanour captivate anyone lucky enough to see them. Gibbons are our evolutionary cousins, and the world would be a much poorer place without them.

Ben Rawson is CI’s regional primatologist for the Greater Mekong Program and coordinator of the IUCN/SSC Primate Specialist Group, Indochina.