ABSTRACT
Ex-situ research in aquariums and zoological settings not only support scientific advancement, they also provide opportunities for education, facilitating both mental and physical stimulation, consequently improving welfare. This study aimed to investigate the impact of cognitive testing on the well-being of a group of male Indo-Pacific bottlenose dolphins. The occurrence of affiliative, aggressive and potentially stereotypical behaviors was assessed based on seven monitored behavior types and compared between "Session days" and "Non-session days." The consistency of the impact was assessed over a three-year period. The analyses revealed that "Play with enrichment," "Affiliative tactile," "Social play" and "Synchronous swim" were significantly higher, while "Aggression" was significantly lower on Session days than on Non-session days. Individual analysis showed significant increase in the positive welfare indicators in all dolphins during Session days. The social network analysis of aggressive interactions between group members also supported an overall decrease of aggression during Session days. These results indicate that dolphin groups that voluntarily participate in cognitive tests under human care benefit from the testing and show an improvement in animal welfare while contributing to scientific advancement.
ABSTRACT
Cognitive enrichment aims to provide animals with opportunities to use their cognitive skills and to promote behaviors associated with positive wellbeing. Cooperation in mammals has been recorded during various behavioral contexts such as hunting, mating, playing, and parental care. Coordinated activity, often with some level of problem-solving action included, is required during cooperation. To investigate dolphins' ability for collaborative problem-solving, an enrichment device was introduced to two adult male Indo-Pacific bottlenose dolphins (Tursiops aduncus). The device contained fish and ice and was designed to be opened by simultaneously pulling on both ends. After repeated presentation, it became apparent that only one dolphin had active interest in the device. To facilitate opportunities for problem-solving by this individual, an alternative collaborator, a human partner, was provided. Still, both dolphins had access to the device throughout the entire experiment. After the first opening, the same dolphin was highly successful in collaborating with the human in both joined (93%) and delayed (100%) partner conditions. The device provided a novel opportunity for the dolphin to use his cognitive skills. Even though only one dolphin participated actively, both dolphins showed varying degrees of interest to the device throughout the study. Both dolphins spent an average of 48% and 16% of their time, respectively, with the device, which resulted in a significant decrease in their other two most frequently observed behaviors: swimming and poolside observation. As a novel cognitive challenge, the device may be considered as a type of cognitive enrichment.
