Change in stingray behaviour and social networks in response to the scheduling of husbandry events

Abstract

Husbandry tasks are often carried out at the same time and in the same manner every day, resulting in the potential for them to become predictable to animals. An unpublished study conducted on a mixed species enclosure of blue-spotted ribbontail rays (Taeniura lymma) and blue-spotted maskrays (Neotrygon kuhlii), reported increased intra and interspecies aggression preceding training sessions that took place at a fixed time. This study monitored the behavioural responses of the rays to training events, when training was carried out on either a predictable or an unpredictable schedule. Overall, incidences of aggression on days when training occurred were lower than when no training took place; however, aggression rates varied according to the schedules of training and group composition. Increased activity levels before a training session suggest anticipation of this event. Comparison of social networks for aggressive interactions between conditions showed species and individual differences in aggression. However, these differences may have been in response to a change in social composition of the group in the middle of the study and not due to differences in study conditions. This study will inform management practice by highlighting the importance of husbandry regimes on animal behaviour.