Whether animals should be provided with food on a short term or ongoing basis after the cage doors are opened is an important decision, and one which should be carefully considered in advance. On one hand, newly released gibbons may require supplemental feeding, known as post-release provisioning, to survive while they map their new territory. Without this nutritional safety net, translocated gibbons can lose body condition during the initial period in the wild while they learn the seasonal fruiting cycles of the local trees. However, post-release provisioning means an ongoing dependence on humans, which comes at a financial and time cost, and the risk that animals continue to view humans as the source of their food.
If post-release provisioning is necessary, all supplemental food should be provided in suspended baskets hauled at least 10 meters high into the tree canopy. This elevated feeding forces the gibbons to remain arboreal and prevents them from developing the dangerous habit of descending to the forest floor to eat. Staff should gradually move these feeding baskets further away from the acclimatisation cage over time to encourage the gibbon(s) to expand their foraging territory.
Initially, staff may provide the same volume of food the gibbons ate in captivity. As monitoring teams confirm that the gibbons are successfully locating and eating wild foods on their own, this supplemental amount should be gradually reduced. It normally takes at least one full year, allowing the gibbons to experience a complete seasonal cycle of fruit abundance and scarcity, for them to become fully independent foragers. However, nutritional demands change based on physiological states. If a released female becomes pregnant or is nursing a newborn infant, staff should monitor the mother more closely to ensure she has sufficient energy intake during this time.
The goal always should be to get to a point when post-release provisioning stops. How quickly this happens depends on the circumstances. While post-release provisioning may assist the monitoring of released animals, generally it is not recommended that supplemental food is provided indefinitely. Well-prepared and suitable gibbons will quickly map their new wild territory and start to adapt to the food available there naturally. Continued food provisioning will reduce their drive to find food for themselves, therefore, it’s best to phase this out as soon as possible.