Exploration of potential triggers for self-directed behaviours and regurgitation and reingestion in zoo-housed chimpanzees

The unique challenges faced by animals living in zoos can lead to the production of anxiety-related behaviours. In this study we aimed to understand what specific factors may cause chimpanzees to display these behaviours. In non-human primates, displacement behaviours, such as self-scratching and yawning, are considered markers of anxiety and stress, and Regurgitation and Reingestion […]

Yawning and thermoregulation

We review a growing body of medical and physiological evidence indicating that yawning may be a thermoregulatory mechanism, providing compensatory cooling when other provisions fail to operate favorably. Conditions such as multiple sclerosis, migraine headaches, epilepsy, stress and anxiety, and schizophrenia have all be linked to thermoregulatory dysfunction and are often associated with instances of […]

The direction and range of ambient temperature change influences yawning in budgerigars (melopsittacus undulatus)

Comparative research suggests that yawning is a thermoregulatory behavior in homeotherms. Our previous experiments revealed that yawning increased in budgerigars (Melopsittacus undulatus) as ambient temperature was raised toward body temperature (22→34 °C). In this study, we identify the range of temperatures that triggers yawning to rule out the possible effect of changing temperature in any […]

Evidence for Contagious Behaviors in Budgerigars (Melopsittacus undulatus): An Observational Studyof Yawning and Stretching

Yawning is contagious in humans and some non-human primates. If there are social functions to contagious behaviors, such as yawning, they might occur in other highly social vertebrates. To investigate this possibility, we conducted an observational study of yawning and an associated behavior, stretching, in budgerigars (Melopsittacus undulatus), a social, flock-living parrot. Flock-housed budgerigars were […]