Understanding the welfare requirements of a neurologically and physically divergent captive male Sumatran orangutan (Pongo abelii)

Background
Understanding the needs of animals with physical and cognitive impairments is essential for zoos, rehabilitation centres, and other captive contexts. This case study describes the atypical physical and cognitive development of Jiwa, an adult male Sumatran orangutan (Pongo abelii), to evaluate how these differences may impact Jiwa and to explore how cognitive enrichment can be tailored to his skill level.

Methods
Keeper records from Jiwa’s birth (1999) to February 2022 were scrutinised to identify key developmental milestones, changes in body weight, and deciduous dental emergence. These were compared with expected milestones for wild and captive orangutans. In addition, a probe feeder apparatus was gradually tailored to an appropriate skill level between January and March 2022.

Results
Many of Jiwa’s developmental milestones were consistent with expected orangutan development, although there were noticeable differences in body weight, dental emergence, locomotion, and cognition. The welfare domains most likely to be negatively impacted by these differences were physical health, expression of agency, and mental wellbeing. After the enrichment device was tailored to an appropriate level of challenge, Jiwa showed marked improvement in engagement and ability to use the device.

Conclusions
This study helps to inform future case studies of atypical great apes by detailing the physical and cognitive development of an individual orangutan. Although Jiwa’s differences may impact his own wellbeing in some areas, he has largely been able to overcome them. However, this case study highlights the challenges involved in tailoring enrichment apparatuses and resilience interventions for atypical individuals.