Preventing young gibbons to become overly accustomed to humans is one of the most critical components of hand-rearing. Inappropriate habituation jeopardises a gibbon’s chances of successful group integration and reintroduction. For the first few weeks of life, the infant must be held constantly to provide necessary warmth and contact, positioned upright close to the keeper’s chest. However, caregivers must avoid holding the infant as if it were a human baby. Because non-human primates instinctively cling to their mothers, surrogates must hold the infant loosely to force the gibbon to actively use its own muscles to grip and hold on. It can help to wear a vest of similar, with appropriate handholds secured to it. When an infant must be set down for weighing or resting, it should always be placed on its stomach and provided with a blanket or a stuffed animal to fulfill its need for tactile security.
As the infant grows and becomes more agile, the nursery environment must be adapted to promote natural locomotion. Initial housing with solid, towel-covered bottoms should be gradually upgraded to include hammocks, branches, and ropes to encourage natural movement. To foster species identity, youngsters should remain in visual contact with other adult gibbons. Furthermore, when the infant reaches approximately two months of age and becomes more aware of its bottle, caregivers should transition to feeding the infant their bottle through a mesh barrier. This mesh feeding is imperative prior to social introduction, as it forces the infant to recognise its independence from the caregiver. Finally, caregivers must model appropriate environmental responses. By reacting calmly to day-to-day noises but holding the infant close during moments of “fright” the surrogate teaches the young gibbon how to appropriately respond to its surrounding environment.
While still under human care, caregivers must model appropriate environmental responses. By reacting calmly to day-to-day noises but holding the infant close during moments of “fright” the surrogate teaches the young gibbon how to appropriately respond to its surrounding environment until they are fully integrated with their conspecifics. Whenever possible, hand-reared gibbons should be peer-reared in juvenile groups. Housing youngsters with conspecifics of a similar age is helpful because it allows them to play, learn vital social cues, and develop appropriate species-specific behaviours naturally, free from constant human intervention.
Beyond peer groups, early socialisation and structured reintroduction to adult gibbons, ideally their original family unit, or a suitable surrogate female/pair, is an important step toward full independence. Once the infant is reliably eating solid foods, requires less frequent milk feeds, and demonstrates physical agility, supervised physical introductions to stable, well-socialised adult gibbons or a surrogate gibbon mother should be prioritised. This early integration allows the youngster to learn complex social dynamics, species-specific vocalisations, and proper locomotion from appropriate adult role models, drastically increasing their chances of long-term success.