Assessment of animal management and habitat characteristics associated with social behavior in bottlenose dolphins across zoological facilities

Abstract

Bottlenose dolphins are a behaviorally complex, social species that display a variety of social behaviors. Because of this, it is important for zoological facilities to strive to ensure animals display species-appropriate levels of social behavior. The current study is part of the multi-institutional study entitled “Towards understanding the welfare of cetaceans in zoos and aquariums” commonly referred to as the Cetacean Welfare Study. All participating facilities were accredited by the Alliance of Marine Mammal Parks and Aquariums and/or the Association of Zoos and Aquariums. Behavioral data were collected on 47 bottlenose dolphins representing two subspecies, Tursiops truncatus and Tursiops aduncus, at 25 facilities. The social behaviors of group related activity (group active) as well as interacting with conspecifics (interact with conspecific) were examined for their relationships to both animal management factors and habitat characteristics. The behavioral state of group active and the rate of interact with conspecific were both positively related to the frequency of receiving new forms of environmental enrichment. Both were inversely related to the random scheduling of environmental enrichment. Additional results suggested interact with conspecific was inversely related with daytime spatial experience and that males displayed group active more than females. Overall, the results suggested that animal management techniques such as the type and timing of enrichment may be more important to enhance social behavior than habitat characteristics or the size of the habitat. Information gained from this study can help facilities with bottlenose dolphins manage their enrichment programs in relation to social behaviors.

The Cetacean Sanctuary: A Sea of Unknowns

“…Both were inversely related to the random scheduling of environmental enrichment [65]. Socialization, on the other hand, is positively related to the frequency of receiving new forms of environmental enrichment but similarly inversely related to enrichment when it is randomly applied [92]. Hence, on some factors, the things that may increase behavioral diversity may decrease habitat utilization, especially regarding social housing [65,116].…”

“…In non-sanctuary facilities, males and females may be housed separately in mixed sex/age groups in which males and females main-tain physical access to each other and in mixed sex/age groups in which animals cannot physically contact either other (but can communicate acoustically, visually, and chemically). While studies are starting to address some of these issues using new, innovative methods [7,65,[92][93][94], more research is needed to establish how each of these different housing types affects animal welfare. We know that managed animals in mixed male and female groups have more diversity in sexual behavior while showing little difference in aggression rates between all male and mixed male and female groups [95].…”

“…Hence, on some factors, the things that may increase behavioral diversity may decrease habitat utilization, especially regarding social housing [65,116]. Sanctuary proponents should consider what aspects of the Cetacean Welfare Study [7] are applicable to their proposed housing method, specifically the studies above, where the predominate findings are that habitat type or size alone does not dictate quality welfare but rather animal management techniques and timing, which play a much larger role in increasing cetacean behavioral diversity, habitat utilization and socialization scores under human care [7,65,92,116,117].…”

Dolphin-WET—Development of a Welfare Evaluation Tool for Bottlenose Dolphins (Tursiops truncatus) under Human Care

“…It has involved several studies identifying potential welfare indicators and investigating the impact of various factors (e.g., housing, management, training, and enrichment procedures) on the welfare of dolphins under human care [ 21 , 22 , 23 , 24 , 25 ]. For example, dolphins engaged in more social interactions and exhibited high group activity rates when new enrichment devices were regularly provided [ 26 ]. Recent studies have pointed out several other promising potential welfare indicators: the behavioural diversity index, which refers to the frequency and variability of species-specific behaviours displayed by an individual, suggests that high behavioural diversity may indicate a positive welfare state [ 3 , 27 ]; predictable training schedules [ 24 ] linked to anticipatory behaviour (another potential welfare indicator) [ 28 , 29 ]; the dolphins’ willingness to participate in training activities [ 15 , 30 , 31 ]; post-conflict behaviours that structure dolphins’ social networks [ 32 ]; and swimming features as potential indicators of the dolphins’ emotional states [ 33 ].…”

Health and Welfare Benefits of Computerized Cognitive Enrichment in California Sea Lions (Zalophus californianus) at the US Navy Marine Mammal Program

“…Through positive reinforcement training, such behaviors can become a stress-free and reliable means of collecting important information [22] that forms the cornerstone of successful preventative medical programs for animals [30]. Most marine mammal welfare research has centered on dolphins, exemplified by the development of the C-Well welfare assessment [31] and the multi-institutional Cetacean Welfare Study [24,[32][33][34][35][36][37][38][39]. Progress with pinnipeds has lagged [40].…”