The Kalaweit Gibbon Re-habilitation Project: rescue, re-introduction, protection and conservation of Indonesia’s gibbons

Summary

The Kalaweit Project rescues and rehabilitates Indonesia's gibbons, all threatened by habitat loss and the illegal pet trade, working across six species and subspecies in Kalimantan, Sumatra, Java, and the Mentawai Islands. Gibbons arrive at Kalaweit care centres when owners can no longer keep them or after confiscation by police or forestry officials, and undergo mandatory medical screening, including tests for malaria, tuberculosis, hepatitis B, intestinal parasites, and herpes simplex virus, before being considered for release, since infected animals can never be released. Because gibbons are monogamous and territorial, only bonded pairs of mature adults are released together, one pair at a time, into forest within their historical range but where they no longer occur, followed by intensive post-release monitoring using ranging patterns and duetting calls to relocate semi-habituated animals. The project also works with local communities on employment, training, and education about the illegal pet trade. Major difficulties included a general lack of published knowledge on gibbon rehabilitation, difficulty confirming sub-species identity, scarce suitable release habitat, and disease risk forcing some rescued gibbons to be excluded from release. The project rated itself Partially Successful, acknowledging mistakes made and corrected as an early-stage program, relatively few pairs released so far due to the lengthy preparation process, and ongoing difficulty finding suitable release habitat, even as dedicated release areas are now being established.