Publications
Social culture in bonobos Royal Zoological Society of Antwerp
Exploring the Utility of Hair Endocannabinoids for Monitoring Homeostasis in Bonobos Royal Zoological Society of Antwerp
Quantifying physiological challenges has gained increasing importance in evolutionary biology, behavioral physiology, and conservation. One matrix that is particularly useful for obtaining long-term records of physiological changes in mammals is hair. Potential markers are components of the endocannabinoid (EC) system, which regulates homeostasis of the brain as well as the endocrine and immune systems. Here, we present results from the first ...
Age-related changes in urinary testosterone levels suggest differences in puberty onset and divergent life history strategies in bonobos and chimpanzees Royal Zoological Society of Antwerp
Research on age-related changes in morphology, social behavior, and cognition suggests that the development of bonobos (Pan paniscus) is delayed in comparison to chimpanzees (Pan troglodytes). However, there is also evidence for earlier reproductive maturation in bonobos. Since developmental changes such as reproductive maturation are induced by a number of endocrine processes, changes in hormone levels are indicators of different developmental ...
Testing the Effect of Medical Positive Reinforcement Training on Salivary Cortisol Levels in Bonobos and Orangutans Royal Zoological Society of Antwerp
The management of captive animals has been improved by the establishment of positive reinforcement training as a tool to facilitate interactions between caretakers and animals. In great apes, positive reinforcement training has also been used to train individuals to participate in simple medical procedures to monitor physical health. One aim of positive reinforcement training is to establish a relaxed atmosphere for situations that, without ...
Age-related changes in Thyroid hormone levels of bonobos and chimpanzees indicate heterochrony in development Royal Zoological Society of Antwerp
We present information on age related changes of thyroid hormone levels in bonobos (N = 96) and chimpanzees (N = 100) ranging between one and 56 years of age. Fresh urine samples were used for hormone measurements with a commercial competitive total triiodothyronine (T3) ELISA. In both species, immature individuals had higher TT3 levels than adults and there was a marked decrease in TT3 levels between age classes. The two species differed in ...
A survey of foot problems, stereotypic behaviour and floor type in Asian elephants (Elephas maximus) in European zoos Royal Zoological Society of Antwerp
This study investigates whether foot problems in captive Asian elephants (Elephas maximus) can be linked to: i) enclosure floor type; and ii) the occurrence of repetitive behaviour. Using a questionnaire, we collected information about floor type(s) in the enclosure, occurrence of repetitive behaviour and occurrence of foot problems for 87 Asian elephants (>= 12 years) in 32 European zoos. The majority of elephants were housed on sand or ...
Group Size of a Permanent Large Group of Agile Mangabeys (Cercocebus agilis) at Bai Hokou, Central African Republic. Royal Zoological Society of Antwerp
White-eyelid mangabeys (genus Cercocebus) live in groups of highly variable size. Because of their semi-terrestrial behaviour and preference for dense forest habitats, re-liable data on group size are scarce. During a 5-month study, we collected 17 group counts on a habituated group of agile mangabeys (C. agilis) at Bai Hokou in the Central African Republic. We found a stable group size of approximately 135 individuals. This permanent large ...
Mechanisms of reciprocity in primates: testing for short-term contingency of grooming and food sharing in bonobos and chimpanzees Royal Zoological Society of Antwerp
Much of the debate about reciprocity in humans and other primates hinges on proximate mechanisms, or more precisely, the contingency of one service on another. While there is good evidence for long-term statistical contingencies of services given and received in primates, results for short-term behavioral contingencies are mixed. Indeed, as we show here controlled experiments using artificial tasks and explicit turn-taking were unlikely to find ...