One challenge in studying the natural behaviour of wild animals is the requirement of detailed observations spanning extended periods of time, which is particularly difficult in the case of sharks. As a result, remote sensing technologies are increasingly employed in which the data received is considerably simplified. In this study, 475 blacktip reef sharks (Carcharhinus melanopterus) were identified using direct underwater observation. Subsequent sightings of these sharks were recorded at various locations along the north shore of Mo'orea Island over a period of 6.5 years. The key factors influencing their movements were found to be the reproductive season and the lunar phase. Additionally, a tendency to avoid turbulent regions was observed, particularly by mature females. Notably, significant variations existed among individuals; while some sharks left their ranges for only two weeks twice a year for mating and parturition, others were frequently absent, sometimes for months at a time. It was also observed that juveniles displayed high mobility prior to settling into a home range around the ages of three to four. Understanding such movements will be useful in the future in the planning of MPAs and other conservation strategies.

The chondrichthyan lineage diverged from the osteichthyan line around 440 million years ago, resulting in a vast evolutionary gulf between modern elasmobranchs and other vertebrates. Though this has supported the assumption that sharks are ancient, dangerous, and binary-minded, intelligent actions including social interactions have been noted in the field, while laboratory studies have confirmed a variety of cognitive capacities. Yet, due to fear of sharks and the difficulties of observing them in their aquatic environments, few ethological studies have been done, so their natural behaviour remains little known. On noting that Carcharhinus melanopterus displayed complex actions during incidental meetings, a long-term ethological study of the species was carried out on the north shore of Mo’orea Island, French Polynesia. During the 6.5 years of the study, new behaviours continued to present. The 35 context-specific actions identified as comprising the behavioural repertoire of C. melanopterus are described.

The present essay illustrates the methodological and theoretical premises of an emerging research area carrying out both ethological and (bio)ethical implications: the ethology of the freed animal (EFA). Unlike existing ethological fields, EFA focuses neither on non human (NH) animals in natural conditions of freedom in their own environment, nor on NH animals kept in conditions of “captivity”. Rather, EFA consists of a comparative study of NH animals that are released from a condition of more or less abusive captivity and instead relocated in an environment more appropriate to their species-specific and individual characteristics and inclinations. Ideal places for this study are contexts like “Animal sanctuaries” and parks/reserves provided with a camp or station for researchers, where a previously-captive NH animal can be reintroduced in his/her natural habitat. Even though EFA exists already, as a de facto practice of the specialized and/or volunteer personnel running sanctuaries and parks, the field still lacks a recognizable scholarly paradigm, and it is yet to be acknowledged at institutional/academic level. By consequence, one important aim for creating a field like this lies in the establishment of an active interaction between the two parties involved (researchers and sanctuaries/parks operators).

We aimed to assess whether play behavior can be used as a welfare indicator for farmed spotted pacas (Cuniculus paca) by examining its association with other positive welfare markers including affiliative behavior and low-amplitude vocalizations. We submitted six groups of spotted pacas (one male/two females per group) (N=18) to an ABA experimental design (A1/A2: without ball; B: with three boomer balls). Play behavior occurred only during phase B (mean=35.5s, SE=6.4). Spotted pacas spent more time in affiliative and exploratory behaviors, while they spent less time engaging in agonistic interactions during phase B than in both control phases (A1 and A2) (P<0.05). Moreover, spotted pacas emitted more low-amplitude bark vocalizations during phase B than during either control phase (P<0.05), which have previously been shown to indicate a positive affective state and low arousal level. Because the expression of play was associated with a decrease in aggression, an increase in affiliative behavior, and an increase in low-amplitude barking, indicating thus a positive state, we suggest that play behavior can be used as a non-invasive indicator of positive welfare in this species.