Cognitive Group Testing Promotes Affiliative Behaviors in Dolphins

Experiments with a set of cooperative enrichment devices used by groups of Indo-Pacific bottlenose dolphins

Dolphins in the wild cooperate to find food, gain and maintain access to mating partners, look after their young ones, or for the sheer joy of play. Under human care, environmental enrichments provide mental and physical stimulation and opportunities for the dolphins to practice their natural abilities. In this review, I focus on a set of enrichment devices we designed for cooperative problem-solving. They allowed the dolphins to utilize and improve their cognitive skills, leading to improved socialization within the group. While the devices provided appropriate challenges to the dolphins, they also allowed the investigation of the impact of demographic and social factors on the cooperative actions. We found that age and relatedness had no impact on cooperation; in turn, cooperation increased with group size. In addition, during the use of these cognitive enrichments, partner preference and intersexual differences were revealed in cooperative actions. The novel multi-partner devices were not only used by dolphin pairs but also by dolphin trios and quartets, providing evidence for group-level cooperation. In addition, a novel food-sharing device was used prosocially by dolphin pairs. Finally, the introduction of these cognitive enrichments leads to measurable short- and long-term welfare improvement. Thus, the use of these cognitive enrichments paired with systematic data collection bridged science with welfare. Future studies will investigate intersexual differences in independent groups, the emergence and function of cooperative interactions, and the socio-dynamics using cognitive enrichments.

Manatees in Zoological Parks throughout the World: History, State, and Welfare

The order Sirenia comprises several species of manatees and one species of dugong. These popular marine mammals are relatively recent acquisitions to zoological parks throughout the world. As far as we know, there are less than 200 manatees, mostly American, a few African, and ever less Amazonian, currently in zoological parks. American manatees are predominantly found in zoos in Europe, North America, and in some Asian countries, while African ones are present exclusively in Asian zoos. The living conditions of captive manatees differ considerably from zoo to zoo (i.e., numbers, sex ratio, outdoor vs. indoor habitats, complex vs. simple habitats). Most research on manatee behaviour has been relatively recent, and studies on cognition, sociality, and ecology have a significant impact on our perception of manatee needs and management, with wider implications for their welfare. In the wild, manatees demonstrated various cognitive capacities; spatial memory and learning abilities play an important role in their daily life in a complex and dynamic environment. Furthermore, there is evidence that these mammals are more social animals than expected. Individuals show various personality traits on the boldness-shyness continuum and their sociality varies. All those parameters are important in terms of animal welfare. Several behavioural studies showed that standardized enrichment programs benefit and ensure the welfare of captive zoo animals. However, obtaining accurate information on the presence of manatees in zoos, living conditions, management, and consequently welfare remains challenging. This study examines the current knowledge on manatee behaviour and cognition and then discusses different approaches to improving the welfare of this charismatic marine mammal in zoological parks.

Cognitive Foraging Enrichment (but Not Non-Cognitive Enrichment) Improved Several Longer-Term Welfare Indicators in Bottlenose Dolphins

Bottlenose dolphins are the most common cetacean kept globally in zoos and aquaria (hereafter zoos), and are gregarious animals with a mostly opportunistic, generalist feeding strategy in the wild. In zoos, they have limited to no opportunities to express natural foraging behaviours as they receive their daily food ration of dead fish in a series of training sessions. Enrichment provision has increased in recent years, but items are still predominantly simple and floating in nature, and do not always target the animals' problem-solving or food-acquisition behaviours. These discrepancies run concurrently with the intense debate about dolphin welfare in zoos and how to improve it. The current study used a within-subject design on 11 bottlenose dolphins at Kolmårdens Djurpark and measured how several welfare indicators differed between two treatments of "cognitive" and "non-cognitive" food-based enrichment. The treatments were provided on an alternating basis for eight consecutive weeks: during cognitive enrichment weeks, the animals received items which stimulated their problem-solving and foraging behaviours, and during non-cognitive enrichment weeks, they received simple items paired with fish (to eliminate bias due to food value). Data were taken related to several multidisciplinary welfare parameters during enrichment provision and training sessions, and to activity budget behaviours throughout the week. During the cognitive as opposed to non-cognitive enrichment weeks, the dolphins engaged more with the enrichment, were more motivated to participate in training sessions and performed less anticipatory and stereotypic behaviours, suggesting that cognitive enrichment improved several indicators of bottlenose dolphin welfare. Valuable lines of further investigation would be to understand how individual differences and different types of cognitive enrichment impact potential welfare benefits. Our results suggest that enrichment items promoting cognitive foraging behaviours may improve dolphin welfare, and therefore zoos might prioritise giving cognitive enrichment to this species as well as considering the same for other species with similar cognitive skills and foraging ecologies.