THE FORGOTTEN APES
what is a gibbon?
Gibbons (Hylobatids) are the smallest of the apes. They diverged ca. 16.8 million years ago. They are distinguished by their ability to brachiate (i.e. swing) through the trees, their small family groups, and their species-specific territorial songs. Including the recent discovery of the Skywalker Hoolock gibbon, there are now 20 known species.
understanding the human-gibbon interface
China is not a homogenous society; it boasts an array of diverse practices, beliefs, psychological perspectives and languages, and therefore a holistic approach to conservation research should be adopted. Gibbons were once widespread across China, but are now restricted to Hainan, Guangxi and Yunnan provinces. Myanmar on the other hand, harbours the vast majority of wild Hoolock gibbons (Hoolock spp.), and potentially the newly discovered Skywalker Hoolock gibbon. Although all gibbon species in China are listed as Class 1 and protected under the 1988 Chinese Wildlife Protection Law, gibbons still face pressures from illegal hunting and habitat loss.
In 2017 I started my doctorate research investigating the patterns and drivers of gibbon decline in China, Vietnam and Myanmar with the hope of informing future conservation management strategies. I am focusing on four species:
Hainan gibbon (Nomascus hainanus): The world's rarest primate with a mere 26-28 individuals remaining;
Skywalker Hoolock gibbon (Hoolock tianxing): A newly discovered species found on the Myanmar-China border;
Cao Vit gibbon (Nomascus nasutus): A species found on the China-Vietnam border with only 110 individuals remaining;
Western Black-Crested gibbon (Nomascus concolor): 2000 individuals found in highly fragmented populatons across China, Vietnam and Laos.
All these species reside in isolated forest fragments in China, Vietnam, Laos, and potentially neighbouring Myanmar. With increasing anthropogenic threats from habitat loss and hunting, effective conservation strategies are of the utmost importance requiring robust, evidence-based understanding of key population parameters, as well as adopting an integrated biosocial approach to provide contextual detail of the human-wildlife issues. My doctorate research uses an interdisciplinary, mixed-method approach, involving both biological and ethnographic methods, to improve our understanding of the human-gibbon interface.
There are varying perceptions and beliefs surrounding gibbons. Many ethnic groups in China for example, believe gibbons are the ‘king of the primates’ and have taboos about hunting, whilst others believe gibbons are vital for medicinal purposes. Limited research has been carried out on the sympatric interactions between humans and gibbons which could offer a more in depth, useful insight into this complex relationship to ensure sustainable coexistence.
The Critically Endangered Hainan gibbon is considered to be the world’s rarest primate with only 26-28 individuals remaining. Endemic to China, it is only found in a 15 km2 fragment of suboptimal forest in Bawangling National Nature Reserve (BNNR) on the island of Hainan in the South China Sea. A 2014 Hainan gibbon workshop between Chinese and international collaborators set clear goals to ensure its survival through continued conservation monitoring and intervention. It was recommended that researchers investigate the spatial patterns and intensity of non-timber forest product use in the area, as well as raising conservation awareness in local communities.
The Skywalker Hoolock gibbon, also known scientifically as Hoolock tianxing, belongs to a group of gibbons called the Hoolocks. Until recently, there were thought to be two Hoolock gibbon species: the Western hoolock (Hoolock hoolock) and the Eastern hoolock (Hoolock leuconedys). These two species are separated by the Chindwin river in Myanmar which acts as a barrier against gibbon movement and dispersal. Such barriers can lead to speciation; the formation of two or more species from the original one. Whilst studying the Eastern hoolock gibbons, researchers soon noticed physical differences in a specific population found in the region known as Gaoligongshan, a geographically isolated mountain range with a high number of endemic species not found anywhere else. By collecting DNA samples and comparing external morphological traits such as dentition and colouration, researchers discovered the new species in 2017.
Researchers have managed to estimate that there are approximately 200 Skywalker Hoolock gibbons on the Chinese side of the border. The exact numbers in Myanmar are currently unknown however.
In 2017 I launched a successful crowdfunding campaign to support my doctorate research. With the support of my dream team (supervisors: Prof. Helen Chatterjee MBE, Dr. Samuel Turvey, Prof. Fan Peng-Fei and Dr. Susan M. Cheyne) I plan to:
Assist with population surveys in Myanmar;
Record important activity budget, feeding and social behaviours;
Collect DNA from faecal and partially masticated plant samples;
Work closely with local communities to understand values and forest resource use;
Compile an evidence-based conservation management action plan.
The Cao Vit or Eastern Black-crested gibbon (Nomascus nasutus) was originally thought to be extinct until its rediscovery in 2002 where only ca. 130 individuals make up the entire population. This Critically Endangered species is now restricted to a small, isolated 80 km2 mountainous karst transboundary forest fragment in northeast Vietnam and southeast China. Although the forest comprising the Cao Vit gibbon range is now protected on both sides and the population is slowly increasing, habitat degradation is still occurring due to charcoal production, selective logging and farmland encroachment. A Population Viability Analysis revealed that the current population could reach its carrying capacity within the next 40 years without adequate conservation management.
Finally, the Critically Endangered Black-crested gibbon (Nomascus concolor) is found in highly fragmented, discontinuous forest across southwestern China, northwestern Laos and northern Vietnam. The global population is thought to be ca. 1300-2000 individuals, where 65% of the population is found in China. Like with all gibbon species, the Black-crested gibbons are heavily threatened by destructive local forest use and hunting, regardless of local taboos on hunting of small apes in these countries