Photo: John Everingham

Being adorably playful, acrobatic, intelligent and eerily human-like, gibbons are experts at living in the top of the rainforest.

However, evolution has not prepared these small long-armed apes for the chainsaw or the shotgun.

Their verdant homes have been turned to wastelands for timber and agriculture while young gibbons are poached to be sold as pets or tourist attractions. All nine species of gibbons are now being pushed to the brink of extinction.

Fortunately the gibbons’ charm and desperate plight have inspired Murdoch researcher Patrick Cullen to find out the best ways to return these endangered apes back to the rainforest.

A poached gibbon’s future as a human plaything is limited, developing 4cm fangs at sexual maturity that are not so attractive for the tourist trade. Highly dangerous and therefore no longer useful, the apes are often discarded or hopefully placed in a local sanctuary like the Gibbon Rehabilitation Project (GRP) in Thailand.

The GRP, like several other projects throughout South-East Asia, attempts to nurse the apes back to health and encourages behaviours that will improve the gibbons’ chances of surviving and rearing offspring in their natural habitat. The final goal is not only to help individual animals but also to rebuild gibbon populations in areas where they have become extinct.

Mr Cullen worked for two years as the Project Manager of the GRP for two years developing better ways to help the gibbons make a smooth transition back to the rainforest. This experience inspired Mr Cullen to turn his energies towards identifying why some reintroduction programs for gibbons were more successful than others.

For his Masters degree at Murdoch University he compared the survival rates of 164 gibbons that had been released from four rehabilitation projects in Thailand, Malaysia and Indonesia between 1966-1997. His Supervisor, Professor Ralph Swan, has spent the greater part of the last decade working on disease and genetic implications in orang-utan rehabilitation.

Mr Cullen found that success varied wildly between the projects, averaging at a survival rate of 26.2% after the first year after release. He predicted that a number of factors could impact on the survival of the animals such as the age of the animal, the type of rehabilitation processes used in each project, the quality of the habitat and the support of the local community.

“Although we cannot change an animal’s past history before they reach a sanctuary, we can find the techniques that best equip it for survival in the wild, and find habitats which are most suitable,” said Mr Cullen.

He found that exposing the gibbon to the jungle environment prior to release and providing supplementary food for the gibbon after release could significantly reduce the risk associated with reintroduction.

“Understandably, juvenile gibbons survive better during rehabilitation as they are more inquisitive and active after release and have not completely patterned their behaviour to be dependent on humans. Many of the adults have spent most of their life incarcerated and become dependent on humans for all their physical and social needs,” said Mr Cullen.

“But if rehabilitation programs can reduce stress, minimise human contact and introduce the animals into their habitat quickly, they have more chance of success.”

Results also showed that the animals survived better in high quality habitat and that it was crucial to gain the support of the local community.

“The key to conservation is to involve and educate local people. If the conservation ethos grows and replaces the unsustainable logging and poaching industries, the animals may have a chance.”

Mr Cullen is currently completing his Masters degree and the results of his research will be used to develop a guide for people undertaking conservation education and rehabilitation.