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In the last 30 years, concerns about animal emotions have emerged from the general public but also from animal professionals and scientists. Animals are now considered as sentient beings, capable of experiencing emotions such as fear or pleasure. Understanding animals’ emotions is complex and important if we want to guarantee them the best care, management, and welfare. The main objectives of the paper are, first, to give a brief overview of various and contemporary assessments of emotions in animals, then to focus on particular zoo animals, that is, marine mammals, since they have drawn a lot of attention lately in regards of their life under professional care. We discuss here 1 approach to monitor their emotions by examining their laterality to finally conclude the importance of understanding animal emotion from a holistic welfare approach.

Exploratory behavior includes all the actions that an animal performs to obtain information about a new object, environment, or individual through using its different senses of perception. Here, we studied the development of the exploratory behavior of a bottlenose dolphin (Tursiops truncatus) calf aged from 39 to 169 days by investigating its acoustic productions in relation to an immersed object handled by a familiar human without without the calf being isolated from the original social group. The study was conducted between July 2015 and January 2016 at Parc Asterix dolphinarium (Plailly, France). Simultaneous audio and video recordings were collected using a waterproof 360° audio-video system named BaBeL, which allows localization of the dolphin that is producing sounds. During 32 recording sessions, for a total duration of 6 hr 55 min of audio-video recordings, 46 click trains were attached to individual dolphins: 18 times to the calf, 11 times to its mother, and 17 times to another dolphin in the pool. When comparing the calf’s acoustical production to its mother’s, no significant differences were found in their click rate, mean click duration, or mean interclick interval (ICI). However, linear regression showed that calfs’ click rates increased with age and mean ICI decreased with age, probably due to an increase in its arousal. This nonintrusive methodology allows the description and analysis of acoustic signal parameters and acoustic exploratory behavior of a dolphin calf within its social group.

Cetaceans are well-known to display various play activities: numerous scientific papers have documented this phenomenon in wild populations and for delphinids under human care. The present study describes analyses of bottlenose dolphin (Tursiops truncatus) interactions with man-made objects introduced to their habitat as part of an environmental enrichment program. At Parc Asterix Delphinarium (France), 9 bottlenose dolphins were presented with 21 different objects. During 17 hours and using object-focal follows, we studied the dolphins’ behaviors directed toward the objects, according to the objects physical properties (i.e. complexity and buoyancy). We also documented the body parts the animals used to manipulate the objects. The results show that young dolphins displayed more playful actions towards the introduced objects than their older conspecifics. In general, subjects preferred the objects classified as simple and floating, they displayed a larger variety of behaviours, they spent more time and were more creative with them than with other types of objects. Finally, there was significantly more contact and “manipulation” with the dolphin head area than with the fins, fluke or other body parts. By analyzing the dolphins’ behaviors and actions they directed towards the introduced objects, the present study discusses meanings dolphins might give to their surroundings and the relevance of play behavior to their welfare.

The aim of this study was to determine whether California sea lions (Zalophus californianus) are capable of using subtle human gestural cues in a series of object choice tests. Four sea lions, housed at  Parc Astérix Dolphinarium (Plailly, France), were tested using three gestural cues: hip-based finger points, chest-based finger points and eye glances (no head movement involved). Above chance performance was found in response to these cues in 4/4, 2/4, and 1/4 sea lions, respectively, suggesting that the sea lions were able to generalize their response from conspicuous pointing gestures to subtle finger pointing, as well as to eye glance cue for one subject. Discrepancies in accuracy rates between the cues confirmed however that conspicuousness of the pointing gesture is determinant for the ability of the sea lions to exploit it efficiently. These findings reinforce the hypothesis that human-socialization of undomesticated species can lead some individuals to develop an affinity for interpreting very subtle human gestural cues.

The “mirror state,” described for human self-recognition, has been found in captive or human-raised species. In marine mammals, bottlenose dolphins and killer whales have shown evidence of body examination, self-directed and contingency checking behaviors whereas false killer whales appeared ambiguous and California sea lions did not recognize themselves in a mirror. Self-recognition processes in wild cetaceans remain unknown. Since 1985, a resident community of Atlantic spotted dolphin (Stenella frontalis) has been studied underwater in the Bahamas. We describe the reaction of free-ranging dolphins during 14 exposures to the presence of a mirror from 1994/1995 and 2004/2005. Responses to the mirror were mixed. Initial reactions of mother/calf groups were to swim around mirror and stay in close physical proximity. Others ignored the mirror entirely, or swam around or underneath. A single male became stationary and postured in an aggressive stance in front of the mirror. The wild spotted dolphins showed a significant preference to exposing and/or orienting their right side to the mirror versustheir left side. We suggest that the animals assign different meanings to a mirror in the wild versus the same object in captivity.

Since 1985, a well-studied community of free ranging Atlantic spotted dolphins, Stenella frontalis, and bottlenose dolphins, Tursiops truncatus, has been observed underwater in the Bahamas. Over this period, the dolphins have become habituated to human swimmers. Long-term underwater observations revealed that some of these dolphins engaged in play behavior using man-made and natural objects in the presence of humans, and allowed humans to interact with them during play. We investigated the dolphins’ play behaviors in response to a more formal two-way communication interface from 1997-2000. Spotted dolphins were exposed to an underwater keyboard in which visual and acoustic symbols represented the objects the dolphins were observed playing with. Objects could be obtained and played with by indicating the appropriate associated symbol. Pointing and triadic gaze between human participants was used to model the system in the presence of dolphins. Our results indicated that human use of the system encouraged the dolphins to attend to activity at the keyboard. Female juveniles, especially six main individuals, were the main players. Dolphins increased their normal levels of associations with certain conspecifics during exposure sessions and also took dominant roles during sessions in the presence of certain conspecifics. Dolphin age class, sex, and levels of synchronization with humans all contributed to the success and level of engagement during exposure sessions between humans and dolphins.

Scientific literature describes the various ways that we perceive animals and their contribution to our humanization. Our understanding of “animality” is changing, corresponding to an ever-increasing general knowledge of animals. Scientific studies provide objective descriptions of the complexity of animal worlds. The present article discusses recent findings on socio-spatiality, social cognition, and self-recognition in various marine mammal species, as well as the relevance and coherence of theories used to explain them. In a constructivist ethological approach, animals are not considered to be mere living organisms or objects, but rather, subjects. All animals use their senses to create relationships with their physical and social environments. Through their perceptions and actions, they give meaning to their surroundings; they enact individual and specific worlds, known as umwelts.The human-animal relationship is an inter subjectivity. Examples from studies of bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca) can be used to hypothesize the existence of a context-dependent situated self. Finally, animal welfare/well-being and the effectiveness of environmental enrichment programs can be re-evaluated in the context of this theoretical framework. In sum, no objective world exists; rather, we propose the existence of multiple context-dependent cognitive and subjective umwelts. The present article is the first to consider marine mammals with this perspective.