When we talk about mental health, we usually think about humans – trauma, grief, depression, and healing. But what if we told you that orangutans can experience these things too?
Most primate species are social animals. In orangutans, the semi-solitary trait is most apparent in adult males, who tend to have large home ranges and spend much of their time alone. In contrast, females and juveniles are still frequently involved in social interactions, whether for play, learning, or observing the behaviour of other individuals around them.
In the wild, orangutans have one of the longest and strongest mother–infant bonds in the animal kingdom. For the first two years of life, infants are in near-constant physical contact with their mothers. They only gain full independence in movement at around 5–6 years old, and they may continue sharing their mother’s nest until they are 6–8 years old. Even at 11 years old, some have been observed returning to “visit” their mothers. This bond is everything. It is not only about learning how to climb or find food – it is about learning safety and trust as the foundation of their life.
Additionally, maternal loss is not the only form of trauma experienced by rehabilitated orangutans. Other individuals arrive after being kept illegally as pets or exploited in entertainment settings, where they may have been forced to perform, exposed to loud and unfamiliar environments, or subjected to “punishment” during training. Others are survivors of forest fires, habitat destruction, or natural disasters that abruptly remove them from their homes. Although these experiences differ in context, they share a common consequence: prolonged stress exposure that can lead to fear conditioning, emotional insecurity, and disrupted behavioural development.
Studies also show that individuals separated too early from their mothers often grow up less social, less dominant, and more affected by stressful experiences (Reimers, et al., 2007). Some may also develop unusual behaviours as coping mechanisms, where we see these patterns in orangutan rehabilitation.
Sura’s story is one of those silent but powerful reminders. He was a baby male orangutan found in a concession area where trees were being cut. A local resident had kept him before finally handing him over. When our veterinary team examined him, they discovered that three fingers on his left hand had been cut off. The wounds were open and appeared to have been caused by a sharp blade.
During quarantine, Sura would only hold tight to his babysitters. He often looked at his cut fingers, as if noticing or reacting to the injury. Today, Sura is a healthy, grown orangutan living on the pre-release island. He has learned to climb again and to adapt. But he still shows one unusual behaviour: whenever humans call him, Sura often covers his face, appearing to avoid eye contact. This may reflect heightened alertness or a coping response formed during early distress. His body healed, but his memory remains.
Other orangutans show different responses. Mema was one of the orangutans confiscated from a local villager who claimed to have come across her whilst searching for firewood in a burned peat area. When our veterinary team examined her, they discovered a wound on Mema’s right arm and small lumps on her torso and hip, suspected to be from air rifle pellets. Sadly, the discovery of these wounds indicates that Mema’s mother was more than likely shot and killed in the forest.
At present, one of Mema’s most notable behaviours is self-hugging. She often wraps her arms tightly around her own body, especially during moments of uncertainty. Self-directed behaviours such as self-hugging have been described in primates as displacement activities, which are associated with internal emotional conflict and are commonly linked to anxiety or stress regulation (Troisi, 2002). Presumably, behaviours such as self-hugging may emerge as part of an individual’s attempt to regulate emotional discomfort in the absence of maternal contact, allowing individuals to restore a sense of calm in situations perceived as unpredictable or stressful.
Healing, however, requires more than time alone. Social support plays an important role in reducing stress and facilitating emotional recovery (Bridgeland-Stephens, Thorpe, & Chappell, 2023). In rehabilitation settings, surrogate mothers step in to recreate aspects of the maternal role, especially through consistent care, physical closeness, and emotional reassurance. These interactions help re-establish a sense of safety for young orangutans who have experienced early disruption.
As individuals begin to feel more secure, they often become more willing to explore their surroundings, interact with peers, and engage in learning opportunities. This growing sense of security allows orangutans to gradually build confidence and develop essential forest skills, such as climbing, foraging, and problem-solving. Such learning processes are critical for survival in the wild and may be difficult for individuals still experiencing high levels of stress or unresolved trauma. Emotional recovery, therefore, directly supports behavioural development, preparing rehabilitated orangutans both psychologically and physically for eventual release.
Many people still do not realise that orangutans can suffer psychologically. We often focus on visible injuries, declining populations, and forest loss. But behind every rescued individual is a story of loss, fear, and hope. If conservation is truly about protecting life, it must include overall well-being. Sura’s strength, Mema’s quiet coping – all remind us that orangutans feel deeply. Their scars may be invisible, but they are real.
References
- Bridgeland-Stephens, L., Thorpe, S. K., & Chappell, J. (2023). Potential resilience treatments for orangutans (Pongo spp.): Lessons from a scoping review of interventions in humans and other animals. Animal welfare (South Mimms, England), 32, e77. https://doi.org/10.1017/awf.2023.97
- Reimers, M., Schwarzenberger, F., & Preuschoft, S. (2007). Rehabilitation of research chimpanzees: Stress and coping after long-term isolation. Hormones and behavior, 51(3), 428-435.
- Troisi, A. (2002). Displacement activities as a behavioral measure of stress in nonhuman primates and human subjects. Stress, 5(1), 47-54.
Text by: Communication Team, BOS Foundation
Will you help us rescue, rehabilitate, and release orangutans back to freedom? We can only save the orangutan together. Thank you!
