The role of great ape behavioral ecology in One Health: Implications for captive welfare and re‐habilitation success

Abstract

Behavior is the interface through which animals interact with their environments, and therefore has potentially cascading impacts on the health of individuals, populations, their habitats, and the humans that share them. Evolution has shaped the interaction between species and their environments. Thus, alterations to the species‐typical “wild‐type” behavioral repertoire (and the ability of the individual to adapt flexibly which elements of the repertoire it employs) may disrupt the relationship between the organism and its environment, creating cascading One Health effects. A good example is rehabilitant orangutans where, for example, seemingly minor differences from wild conspecifics in the time spent traveling on the ground rather than in the forest canopy can affect an individual's musculoskeletal and nutritional health, as well as social integration. It can also increase two‐way transmission of infectious diseases and/or pathogens with local human populations, or potentially with neighboring wild populations if there are no geographical barriers and rehabilitants travel far enough to leave their release area. Primates are well known ecosystem engineers, reshaping plant communities and maintaining biodiversity through seed dispersal, consuming plants, and creating canopy gaps and trails. From the habitat perspective, a rehabilitant orangutan which does not behave like a wild orangutan is unlikely to fulfill these same ecosystem services. Despite the importance of the diversity of an ape's behavioral repertoire, how it compares to that of wild conspecifics and how it alters in response to habitat variation, behavior is an often under‐appreciated aspect of One Health. In this review, focusing on orangutans as an example of the kinds of problems faced by all captive great apes, we examine the ways in which understanding and facilitating the expression of wild‐type behavior can improve their health, their ability to thrive, and the robustness of local One Health systems.

Assessing the impact of forest structure disturbances on the arboreal movement and energetics of orangutans—An agent-based modeling approach

“…In addition, the use of the BORNEO for Population Viability Analysis at the landscape level can provide insights for conservation guidance for this endangered primate as has been demonstrated for other species (Imron et al, 2011). Expansion of BORNEO for mitigating human-orangutan conflicts (Meijaard et al, 2011) would also provide opportunities to further understanding new emerging diseases as part of the one-health issue (Chappell and Thorpe, 2022).…”

Potential resilience treatments for orangutans (Pongo spp.): Lessons from a scoping review of interventions in humans and other animals

“…However, there is a wide variety of forest school capacity and enclosure sizes among different rehabilitation centres, and not all centres have access to pre-release islands. Therefore, careful consideration should be given to the provision of in-cage physical enrichment and roof feeding (Chappell & Thorpe 2022 ), and, in the longer term, building larger enclosures.…”

“…Although natural enrichment may be preferable, the practicalities of this with larger animals can be complicated, as enrichment and enclosure features must also be durable and not easily destroyed. Chappell and Thorpe (2022) argue that non-natural enclosure modifications can simulate the mechanics of a natural environment and provide similar physical and cognitive challenges to those provided by wild environments. However, moving from an enriched to a barren environment can be more harmful than only experiencing barren environments (Bolhuis et al 2006).…”

“…Life in the wild for the world’s largest arboreal mammal (Cant 1992 ) is extremely demanding. Released orangutans will need to face challenges such as the physical and cognitive requirements of travelling through the forest canopy and building appropriate nests (Thorpe et al 2007 ; van Casteren et al 2012 ; Halsey et al 2017 ), coping with unpredictable food scarcity (Knott 1998 ), encountering unfamiliar or difficult-to-process food (Jaeggi et al 2010 ), interacting with other orangutans, and managing potential conflict with humans and other dangerous animals (Meijaard et al 2011 ; Chappell & Thorpe 2022 ). In addition, when female orangutans breed successfully after being released, they must face all these challenges while providing their infants with extensive care until weaning, without having had the opportunity to experience species-typical maternal care from their own mothers.…”

Primatology and one health: Two disciplines destined to come together

“…GAHMU and the associated conferences in Leipzig Germany and Entebbe Uganda inspired many of us interested in great ape health to examine health and disease under the over‐arching umbrella of One Health (Leendertz et al, 2006). Chappel and Thorpe (2021) discuss how behavior is often a forgotten aspect of One Health, and that giving rehabilitant great apes the behavioral and physical tools to learn what they refer to as “wild‐type” behaviors should be included in ape conservation plans as part of a One Health system. Zimmerman et al (2022) review the current great ape disease surveillance systems in both Africa and Asia and suggest that these need to be standardized to be better sentinels of potential disease outbreaks in both humans and great apes.…”