Search

Simple Summary: Fewer than 200 manatees are hosted permanently by zoological parks worldwide. Their living conditions differ considerably from zoo to zoo. Recent research on ecology, acoustics, cognition and behaviour has changed the perception humans have on manatees with implications for their welfare. Using the five-model approach, this study examines our current knowledge on manatees' behaviour and cognition, and suggests ways to improve their welfare in zoological parks. 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. [ABSTRACT FROM AUTHOR]

Some moral behaviours, often regarded as reflecting high cognitive abilities (such as empathy, cooperation, targeted helping) are known to only be present in very few species, like great apes, elephants and cetaceans. Prosocial behaviours (producing a benefit for the recipient without necessarily involving a cost for the actor) have been mostly found in primates and, more recently, in elephants. Despite dolphins' reputation for helping their conspecifics, experimental studies about their prosocial and empathic abilities are rare. We conducted Prosocial Choice Tests in six bottlenose dolphins. The subjects had to choose between three objects: choosing the prosocial object induced the simultaneous rewarding of both the subject and a recipient individual; choosing the selfish object induced a reward only for the subject; choosing the null one did not reward anyone. We found prosociality and direct reciprocity in our subjects, and our results suggested that bottlenose dolphins might be able to modulate their prosocial and reciprocal tendencies according to partner-specific information. Subjects seemed to be more prosocial towards the other sex and more reciprocal towards same-sex recipients. This reciprocity might be underpinned by the same features that rule their behaviours in the wild (cooperating with same sex conspecifics). Moreover, an audience effect was reported, as the presence of the subject's young increased subjects' likelihood of prosocial response. Our findings highlighted that prosociality could appear in taxa other than primates, suggesting a convergent evolutionary phenomenon. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Although relatively rare, adoptions have been reported in a number of mammals, involving almost exclusively individuals of the same species, and hardly ever between species or across genera. Adoption remains poorly documented and its proximate causes are controversial. Here, we describe a unique case of a cross‐genus adoption within a small community of common bottlenose dolphins (Tursiops truncatus) at Rangiroa Atoll in French Polynesia. It involves a foster female adopting a presumed melon‐headed whale (Peponocephala electra) calf while already mothering its presumed biological offspring. While the inclusive fitness hypothesis can be rejected for this adult female mother, acquisition of parental skills is also unlikely to have driven adoption in parallel to natural motherhood. We argue that the primiparous foster mother's inexperience and personality may have contributed to factors driving such non‐adaptive behavior. We also propose that the adoptee's persistence in initiating and maintaining an association with the adult female bottlenose dolphin could have played a major role in the adoption's ultimate success, as well as the persistence of this cross‐genus adoption after the disappearance of the biological offspring. A brief discussion of adoption and hybridization within the Delphinidae taxon is included to identify how this cross‐genus adoption fits into context of marine mammal parental care. [ABSTRACT FROM AUTHOR]

Highlights • Under human care dolphins use echolocation towards immersed non-alimentary objects. • Acceleration of the Inter-Click-Interval (ICI) in approach phase. • ICI deceleration before touch of the object takes over from echolocation. • No sound production while contact lasts. Abstract Odontocetes modulate the rhythm of their echolocation clicks to draw information about their environment. When they approach preys to capture, they speed up their emissions to increase the sampling rate of "distant touch" and improve information update. This global acceleration turns into a "terminal buzz" also described in bats, which is a click train with drastic increase in rate, just as reaching the prey. This study documents and analyses under human care bottlenose dolphins' echolocation activity, when approaching non-alimentary targets. Four dolphins' locomotor and clicking behaviours were recorded during training sessions, when sent to immersed objects pointed by their trainers. Results illustrate that these dolphins profusely use echolocation towards immersed non-alimentary objects. They accelerate click emission when approaching the target, thus displaying a classical terminal buzz. However, their terminal buzz slackens off within a quarter of second before the end of click train. Typically, they decelerate to stop clicking just before they touch the object using their rostrum lower tip. They do not emit clicks as the contact lasts. In conclusion, when exploring inert objects, bottlenose dolphins under human accelerate clicking like other odontocetes or bats approaching preys. Bottlenose dolphins' particular slackening-off profile at the end of the buzz shows that they anticipate the moment of direct contact, and they stop just as real touch relays distant touch of the object. [ABSTRACT FROM AUTHOR]

The welfare of a range of terrestrial animals can now be objectively estimated thanks to the wellestablished, but still expanding, field of welfare science. Despite continuing difficulties regarding definitions, it is generally agreed that welfare is assessed most accurately using multiple "animal-based measures"-that is, those evaluating aspects of the animal itself such as its behaviour. In addition, scientists combining behavioural, physiological, and cognitive animal-based indicators of welfare have found this approach is superior to using one-dimensional measures. But can the same approaches be used for marine mammals, and would assessments of their welfare have the same relevance in captivity as in wild environments? There is no reason why not, and we review the past decades of marine mammal research relevant to welfare, as well as the more recent advances in the field where this topic is starting to be addressed directly. We then use the example of bottlenose dolphins (Tursiops truncatus) to examine what the measures within an all-encompassing (i.e., "comprehensive") welfare assessment might look like. Looking to the future, we suggest directions for developing assessments for captive animals and explore how protocols might differ in wild settings. In conclusion, we find that the first steps are being made towards objectively assessing marine mammal welfare in captivity-through application of terrestrial animal approaches as well as through novel paradigms. Regarding bottlenose dolphins, several welfare measures have been proposed and should now be further validated and applied. It is hoped that this review will encourage continued research in marine mammal welfare assessment given the demonstrated initial achievements of bottlenose dolphin welfare studies and the potential for application to many different captive and wild contexts. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This experiment investigated the ability of four human-socialized sea lions to exploit human communicative gestures in three different object-choice tasks based on directional cues emitted by their caretakers. In Study 1, three of the tested subjects were able to generalize their choice of the pointed target to variations of the basic pointing gestures (i.e., cross-body point, elbow point, foot point, and gaze only), from the very first trials. Study 2 showed that the subjects could follow the pointing gestures geometrically and select the correct target among four possible targets, two on each side of the informant. In Study 3, we tested the robustness of their tendency to follow a pointing gesture by hiding targets behind barriers. One subject was able to follow pointing gestures towards targets not visible at the moment of their decision without any training, despite the presence of another visible and directly accessible one. Taken together, these results suggest that sea lions were able to use the referential property of the human pointing gesture, because they were able to rely on extrapolating precise linear vectors along different pointing body parts in order to identify a precise object rather than merely a general direction. These findings support previous arguments that some non-domesticated species might have as great an ability to respond appropriately to pointing gestures as domesticated dogs. The potential roles of human-socialization and specific features of wild sea lions ecology are discussed. [ABSTRACT FROM AUTHOR]

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 versus their left side. We suggest that the animals assign different meanings to a mirror in the wild versus the same object in captivity. [ABSTRACT FROM AUTHOR]

In this paper, we present a review of the current knowledge related to the cognitive abilities of the manatee, with a focus on the Antillean manatee in situ and ex situ. Following a biocentric approach, we consider the animals' ecology, perception and sociality and we introduce future perspectives on their cognition. Scientific literature on the cognitive abilities of Antillean manatees' is limited and mainly linked to medical training and veterinary manipulations. To perceive and to interact with their social and natural environment (e.g. social interactions, foraging and traveling), manatees use visual, acoustic and tactile modalities that may be involved in a large range of cognitive abilities. Research on stimuli perception in manatees is scarce; however, these animals demonstrate abilities to learn and appear to show long-term memory. For example, to mate and/or to forage manatees travel at medium and large geographical scales; without doubt their movements entail the use of a set of stimuli and learning processes. Furthermore, their social skills (e.g. social organization, tactile and acoustic communications) are also poorly understood although their social interactions appear to be more complex than previously thought. Finally, as for many animals, temperament/personality may play a key role during their interactions with conspecifics and the environment. These aspects on manatee behavior and cognition are important for management and conservation purposes and help us understand the evolution of these marine mammals. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We studied the dolphin’s capacity to perform a cognitive task when information arrives through two different sensory modalities (visual and auditory). Three female bottlenosed dolphins ( Tursiops truncatus) were submitted to a two-, three-, or four-choice visually combined with auditory discrimination problem without any food reward. Since they were not isolated, we examined the significance of the role of identified social constraints on the learning process. The results tended to show an ability to associate simple visual forms and auditory information using an underwater touchscreen. This task was learnt in various ways according to identified social constraints. For each subject, we examined and discussed the number of successful answers, their ability to focus attention on the test and to acquire, or not, the specific task, while noting influences of the social interactions and the social hierarchy on the whole acquisition process. [ABSTRACT FROM AUTHOR]

Simple Summary: For the first time, a behavioural diversity study was conducted on several bottlenose dolphins (Tursiops truncatus) groups within European Association of Aquatic Mammals (EAAM) accredited facilities. This study was carried out by professional animal staff on 54 dolphins, and the goal was to analyse behavioural diversity in bottlenose dolphins at the group level to investigate how particular factors might impact the diversity of behaviours within the group and to discuss its implications for dolphin welfare assessments. This study showed its feasibility and revealed impacting factors that would need to be considered in future dolphin welfare assessments. We strongly believe that behavioural evaluations and measurements could be applied routinely on cetaceans under professional care to assess their welfare. In the recent past, animal welfare studies have tried to determine the best animal welfare measures and indicators. Expression of behavioural diversity is considered a potential positive welfare indicator, and to the authors' knowledge, it has not been validated nor studied in cetaceans. For the first time, a behavioural diversity study on bottlenose dolphins (Tursiops truncatus) groups was conducted at six European facilities. The study was carried out by the animal care staff, biologists and veterinarians and included 54 dolphins housed in several group compositions at the different participating facilities. The goal of our study was to analyse behavioural diversity in bottlenose dolphins at the group level to investigate how particular factors might impact the diversity of behaviours within the group and to discuss its implications for dolphin welfare assessments. Eight factors (i.e., "observer location", "number of individuals", "age class", "sex", "social grouping", "presence/absence of leading male", "presence/absence of visitors" and "enrichment provision") impacted the behavioural diversity of the observed groups, while no significant impact of the factors "time of day" and "activity before/after observation" could be found. Our study showed the feasibility of this kind of approach for cetaceans under professional care and the relevance to considering this parameter in dolphin welfare studies, despite certain limitations that warrant further research. [ABSTRACT FROM AUTHOR]

Exploratory behaviors describe the actions performed by an animal to obtain information on an object, environment, or individual by using its different senses. Exploration is described in some marine mammals, but not yet in manatees. Our study investigated behavioral and acoustic responses of two groups of Antillean manatees (N = 12 and N = 4) housed in zoological parks toward various stimuli involving three sensory modalities: visual, tactile, and auditory. Simultaneous audio and video recordings were collected during three periods of time (i.e., before, during, and after the presentation of all stimuli). Behaviors related to interest, social behaviors, the number and type of calls produced, and their frequency and duration were recorded and analyzed. Manatees reacted more to submerged stimuli than to out-of-water and sound stimuli, with an increase in approach, social contacts, and number of vocalizations. The proportion of squeaks and squeals call types also varied according to stimuli, and call entropy and F0 range varied according to periods. Our results suggest that manatees display sensory preferences when exploring stimuli, with more interest in manipulable stimuli, supporting the importance of their somatic perception. We highlight the need for particular enrichment programs (i.e., involving submerged objects) in zoological facilities. By displaying social contacts and by producing vocalizations, manatees communicate information such as their motivational state. The increase in call rate, harsh calls, and entropy values could be valid indicators of heightened arousal. We encourage further studies to associate acoustic recordings with ethological data collection to increase the understanding of manatees' behaviors andperception. [ABSTRACT FROM AUTHOR]

Simple Summary: The welfare committee of the European Association for Aquatic Mammals (EAAM) set up a group of experts on welfare science, cetacean biology, and zoo animal medicine across Europe to develop a comprehensive tool to evaluate the welfare of bottlenose dolphins (Tursiops truncatus) under human care named Dolphin-WET. The tool encompasses 49 indicators (i.e., 37 animal-based and 12 resource-based indicators) inspired by Mellor's Five Domains Model and the Welfare Quality®. The Dolphin-WET is a species-specific and individual-based welfare assessment tool that provides a holistic approach to evaluating bottlenose dolphins' welfare. Ensuring high standards of animal welfare is not only an ethical duty for zoos and aquariums, but it is also essential to achieve their conservation, education, and research goals. While for some species, animal welfare assessment frameworks are already in place, little has been done for marine animals under human care. Responding to this demand, the welfare committee of the European Association for Aquatic Mammals (EAAM) set up a group of experts on welfare science, cetacean biology, and zoo animal medicine across Europe. Their objective was to develop a comprehensive tool to evaluate the welfare of bottlenose dolphins (Tursiops truncatus), named Dolphin-WET. The tool encompasses 49 indicators that were either validated through peer review or management-based expertise. The first of its kind, the Dolphin-WET is a species-specific welfare assessment tool that provides a holistic approach to evaluating dolphin welfare. Inspired by Mellor's Five Domains Model and the Welfare Quality®, its hierarchical structure allows for detailed assessments from overall welfare down to specific indicators. Through combining 37 animal-based and 12 resource-based indicators that are evaluated based on a two- or three-level scoring, the protocol offers a detailed evaluation of individual dolphins. This approach allows for regular internal monitoring and targeted welfare management, enabling caretakers to address specific welfare concerns effectively. [ABSTRACT FROM AUTHOR]

Harbor seals in the wild live in a stimulating environment; therefore, nonhuman-animal caretakers have increasingly been using environmental enrichment to improve the well being of seals under human care. The purpose of this study was to evaluate an object-based environmental enrichment program during a four-month period on stimulating exploration and play and improving conspecific social interactions and human–animal relationships (HAR). Zoo staff conducted the environmental enrichment program as part of the animal care program. Seals were given objects haphazardly and were observed for 20 minutes, and seals' responsiveness during training sessions before and after enrichment was assessed. Seals showed interest in objects throughout the study and interacted more times per session with objects during the later months. Seals showed preferences for objects that were suspended in the water column (e.g., rope). Seals did not show more affiliative behavior but did show some aggressive behavior during enrichment sessions in comparison with free-swimming sessions. One seal showed better responsiveness to trainers in training sessions that followed an enrichment session than in other trainings sessions. Overall, the enrichment program was successful in increasing intrinsically motivated behaviors and showed that object-based enrichment has the potential to improve HAR between seals and their trainers. [ABSTRACT FROM AUTHOR]

Motor lateralization is a behavioural asymmetry between the left and the right side of an individual due to hemispheric specialization. The right hemisphere controls the left side of the body and the left hemisphere the right side. The right hemisphere processes negative emotions such as fear and frustration, and on the contrary, the left hemisphere processes positive emotions such as happiness. This study, conducted at Parc Asterix Delphinarium (Plailly, France), tested the influence of supposedly positive, negative and neutral emotional situations on four California sea lions' ( Zalophus californianus) motor lateralization while performing a known exercise, here climbing on a stool. Latency between the caretakers' command and the animals' response was recorded. The results showed an interindividual variability in the effect of the supposed emotional situations on their motor lateralization and their response latency. The nature and the strength of this effect require deeper investigation by further studies, on a larger number of individuals and contexts. [ABSTRACT FROM AUTHOR]

Cognitive bias tests measure variation in emotional appraisal and are validated methods to assess animals’ affective states. However, the link between social behaviours and cognitive bias has not yet been investigated. Bottlenose dolphins are a gregarious species for whom welfare research is increasing in importance, and thus are a good model to test such an association. We adapted a spatial location judgement bias test for eight captive bottlenose dolphins to investigate the link between cognitive bias and social behaviour, where we conducted behavioural observations outside of training sessions and did not experimentally induce an affective state. Subjects showed stable individual differences in cognitive biases across the three test days. Furthermore, dolphins showing more synchronous swimming, a fundamental affiliative behaviour, judged ambiguous cues significantly more optimistically. Our longer-term data showed cognitive bias and synchronous swimming frequency were significantly associated for up to two months preceding the test, but disappeared prior to that, suggesting that here cognitive bias differences were reflected by transitory affective states rather than longer-term traits. We hypothesise that the frequency of synchronous swimming may induce affective states and/or be induced by them; either way, it has strong potential as an indicator of affective state in this species and beyond. [ABSTRACT FROM AUTHOR]

• During training sessions, bottlenose dolphins are visually left lateralized. • They display more emotional reactions when negative stimuli are first presented on their left than right side. • Visual and motor laterality appears to be a potential indicator for future dolphin welfare assessment. Hemispheric lateralization is a specialized neural and cognitive processing achieved preferentially by either the left or the right hemisphere of the brain. Among vertebrates, emotions processing seems to be lateralized, but the involvement of each hemisphere is still on debate. Our study investigated visual and motor laterality on five bottlenose dolphins' (Tursiops truncatus) during spontaneous and experimentally induced emotional contexts. We measured motor laterality in pectoral used and swimming position during positive social interactions. Additionally, during training sessions, stimuli with positive or negative emotional valences were presented either on the dolphins' left or right side. Emotional reactions toward stimuli were measured and a visual laterality index was calculated. Dolphins were visually left-lateralized during training sessions. They also reacted more when negative stimuli were presented on their left side than right side during the first stimuli presentation. Our results suggest that bottlenose dolphins, like other vertebrates, may present a right hemisphere dominance for social information processing, detection of and response to unpredictable or novel stimuli and a left-hemisphere dominance during escape responses inhibition. Further studies on a larger sample size should explore inter-individual variation and identify other potential contexts in which lateralization emerges. Emotional lateralization should be considered as a potential indicator for future dolphin welfare assessment. [ABSTRACT FROM AUTHOR]

While the bottlenose dolphin (Tursiops truncatus) is the most studied and widespread cetacean in captivity, studies assessing its welfare have been developed only recently. Several studies focus on a potential indicator of stress: fecal glucocorticoid metabolites (FGM) concentration, which is expected to increase when the hypothalamic-pituitary-adrenal (HPA) axis is activated. However, a lack of studies that consider the biological variation of FGM concentrations related to sex and seasons, and the link to dolphins' reproductive status still impairs our ability to use it for monitoring purposes in the context of welfare assessment. Therefore, it is essential to explore and assess the potential influence of these factors on the variation of FGM concentrations in dolphins. In parallel, non-invasive sampling and methods of measurement should be developed. Thus, the authors performed a methodological validation of enzyme immunoassay (EIA) for FGM in bottlenose dolphins and studied the influence of reproductive status, sex, and seasons on FGM concentrations. The findings showed significantly higher FGM concentrations in pregnant females than in other dolphins, and significantly higher FGM concentrations in males than in nonpregnant females. Moreover, only males showed higher concentrations during spring than during autumn and winter. In parallel, megestrol acetate used for male contraception and pregnancy in females appeared to inhibit and stimulate the HPA axis, respectively. This study creates new opportunities to use EIA as a tool for monitoring FGM concentrations in dolphins and provides new data on its biological variations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Anticipatory behaviour describes the actions taken to prepare for an upcoming event. Bottlenose dolphins ( Tursiops truncatus ) in captivity are known to display anticipatory behaviours before feeding sessions, but it is unknown whether they would anticipate non-alimentary events. Furthermore, there is no published information available for any species on whether the level of anticipatory behaviour is predictive of an animal’s actual participation in the following event or reward: answering this question would bring us closer to understanding this behaviour and its related affective states. In this study, we used sound cues to condition dolphins to the arrival of toys in their pool or a positive Human-Animal Interaction (HAI) with a familiar trainer, and measured their anticipatory behaviour before each event. The protocol was validated since the dolphins performed significantly more anticipatory behaviour before the toys and HAI contexts than a control situation, by means of increased frequencies of surface looking and spy hopping. Furthermore, we found that dolphins showed more anticipatory behaviour before the HAI than the toys context (Linear Mixed Model with 1000 permutations, all P <  0.001). In the second part of the investigation, higher anticipatory behaviour before toy provision, HAIs, and feeding sessions was significantly correlated to higher levels of participation in the event itself (measured by time spent with humans/toys, and number of times dolphins left during feeding sessions; LMM with 1000 permutations, respectively: β  = 0.216 ± 0.100 SE, P  = 0.039; β  = 0.274 ± 0.097 SE, P  = 0.008; β  = −0.169 ± 0.080 SE, P  = 0.045). Our results suggest that toys and HAIs were perceived as rewarding events, and we propose that non-food human interactions play an important role in these animals’ lives. We also provide some of the first empirical evidence that anticipatory behaviour is correlated to the level of participation in the following event, supporting anticipatory behaviour as a measure of motivation, and hope that this stimulates further work regarding the use of this behaviour to assess and improve animal welfare. [ABSTRACT FROM AUTHOR]

Behavioral patterns are established in response to predictable environmental cues. Animals under human care frequently experience predictable, human-controlled events each day, but very few studies have questioned exactly how behavioral patterns are affected by such activities. Bottlenose dolphins (Tursiops truncatus) maintained for public display are good models to study such patterns since they experience multiple daily human-controlled periods (e.g., shows, training for shows, medical training). Thus, we investigated the effect of training session schedule on their "free-time" behavior, studying 29 individuals within 4 groups from 3 European facilities. Our initial time budget analyses revealed that among the behaviors studied, dolphins spent the most time engaged in synchronous swimming, and within this category swam most at slow speeds and in close proximity to each other. "Slow-close" synchronous swimming peaked shortly after training sessions and was low shortly before the next session. Play behavior had significantly higher frequencies in juveniles than in adults, but the effect was only seen during the in-between session period (interval neither shortly before nor after sessions). Anticipatory behavior toward sessions was significantly higher shortly before sessions and lower afterward. We conclude that dolphin behaviors unconnected to the human-controlled periods were modulated by them: slow-close synchronous swimming and age-dependent play, which have important social dimensions and links to welfare. We discuss potential parallels to human-controlled periods in other species, including humans themselves. Our findings could be taken into account when designing welfare assessments, and aid in the provision of enrichment and maintaining effective schedules beneficial to animals themselves. [ABSTRACT FROM AUTHOR]

Nature-based tourism has surged in recent years with the desire for up-close interactions and "connections" with wild animals. The conservation value, animal welfare considerations, visitor satisfaction, and profitability of wildlife tourism are often in direct conflict with trade-offs commonly accepted. In this paper, we reviewed more than four decades of literature on the deleterious behaviors and risks documented during close tourist and other recreational interactions between humans and free-ranging dolphins and encounters between humans and lone, sociable dolphins. Our compilation provides a geographical, chronological, and qualitative overview of these encounters, reviews both humans' and dolphins' deleterious behaviors during interspecific interactions and summarizes the main risks to both humans and dolphins during close encounters. Based on this review, we outline and discuss how both animal welfare and human safety should be managed such that these activities are sustainable; the demand for personal wildlife experiences continues to grow at an alarming rate and the economic pressures placed on wild animal populations run the risk of damaging the very environmental assets that support this industry if they cannot be managed effectively. • The desire for close-up interactions with iconic species has boomed in recent years. • Geographical and chronological content is reviewed for human-dolphin close encounters. • Human intrusive behaviors toward dolphins are documented most. • Increased dolphin tolerance is associated with a high risk of deleterious outcome. • Animal welfare and human safety should be managed in sustainable activities. [ABSTRACT FROM AUTHOR]

Bottlenose dolphins (Tursiops truncatus) are highly social odontocetes that live in a fission-fusion society and demonstrate production of a varied sound repertoire, including clicks, whistles, and burstpulsed sounds, as well as a diverse behavioral repertoire. To better understand the species' behavior, it is necessary to compare visual and acoustic observations and link vocalizations to individuals and their specific actions. However, the task of linking sounds to individual dolphins is challenging for human observers because dolphins do not always display specific visual cues when producing a sound, and also because human hearing is not naturally adapted to locate underwater sound sources. To respond to these challenges, a new underwater 360° HD audio-video device, the BaBeL, was designed and built. This device consists of a five-hydrophone array attached to two wide-angle video cameras that together cover a 360° field of vision. Acoustic recordings were analyzed with a custom- ized program to detect and localize sound sources and to identify individual vocalizing dolphins. Data from a population of bottlenose dolphins were collected during 14 boat surveys along the northwest coast of Reunion Island (France) by following a strict pre-established protocol to standardize data collection. A total of 21 min of audio-video were recorded when dolphins were present, and 42 click trains and 42 whistles were detected from these data. Dolphins identified as vocalizers were also present for 17% (n = 7) of emitted click trains and 33% (n = 14) of emitted whistles on the videos. Therefore, an analysis of three video sequences as examples of the scope of this methodology is presented. The results show that when the observers stayed ahead and avoided the direct path of groups of five to nine dolphins, only one animal emitted click trains while swimming towards the observers or after turning its rostrum in the humans' direction, and this dolphin was never the one leading the group. The benefits of using this audio-video device for underwater observations of dolphins in clear water with good visibility are discussed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Temperament, i.e. consistent inter-individual differences in behavior, has been documented in many species. Especially, boldness-shyness continuum is the ecologically relevant trait most frequently used to describe temperament among species. Reactions along the bold-shy axis demonstrate an organism's ability to cope with environmental conditions and reflect its response to environmental stress. Our study investigated the existence of boldness-shyness continuum in 16 captive Antillean manatees (Trichechus manatus manatus) housed in 2 zoological parks. We first aimed to establish a valid methodology to measure boldness and shyness using behavioral tests. Additionally, our study explored 2 other potential temperament dimensions: sociality and reactivity to humans, and their association with boldness. Finally, since animals were kept under human care, we investigated human perception on manatees' temperament. We conducted behavioral tests i.e. novelty tests involving novel objects, a novel sound, and an unfamiliar human. We recorded behaviors related to exploration as well as social interactions (i.e. physical proximity, social contacts) and we assessed manatees' reactivity to humans through a participation score during hand-feeding sessions. Finally, we collected keepers' subjective impression about individuals' temperament through traits rating method. To our knowledge, this is the first paper that tested manatees' reactions to different novel stimuli in order to determine their temperament. Our results first allowed us to identify the most relevant stimuli and variables to measure boldness and to classify individuals as bolder or shier. Individuals characterized as bolder displayed significantly more approach, longer approach and more contact toward stimuli than shier individuals. Moreover, boldness score was significantly associated with physical proximity with conspecifics, as well as with the participation score to hand-feeding sessions in one zoo. Finally, surveys completed by keepers were reliable and positive associations were found between rated items and behavioral observations. These findings support that as many species, manatees demonstrate boldness-shyness traits. More investigations on a larger sample size are needed to explore manatees' temperament dimensions, and how these traits could modulate their interactions with their conspecifics and their environment. Studying manatees' temperament could help improving the management and welfare of the species under human care. It could also facilitate their management in wildlife reserves by understanding manatees' movements and evaluate the anthropogenic impact on wild populations. • Manatees have bold or shy personality • Boldness score was positively associated with social proximity and reactivity to keepers • Keepers' surveys were reliable and some traits were consistent with behavioral observations • Novelty test seems to be an efficient tool to measure boldness in manatees [ABSTRACT FROM AUTHOR]

Behavioural research in endangered manatees is essential for successful conservation management. We examined the activities and social interactions of a captive group of Antillean manatees located in the Dolphin Discovery Park in Mexico. The group studied was composed of two adults, one subadult and one calf. We determined activity patterns and space use of the manatees in a natural water pool over a daytime period and a night-time period. The behavioural strategies of the manatees included (1) during the day, mainly foraging, feeding, and remaining inactive, and (2) evening activities were divided among social interaction, environment exploration, and resting activities. All the behaviour patterns of the captive manatees seemed to be influenced by the feeding schedule during the day. The number of contacts between manatees increased strongly at night, each individual having a preferred partner for social interaction. The cow-calf dyad showed the highest intensity of contacts, whereas subadults showed the lowest. The relationships observed among individuals reveal a higher social activity than previously described in Antillean manatees. [ABSTRACT FROM AUTHOR]

Simple Summary: Whale and dolphin watching have expanded worldwide, with their impacts on cetaceans over the short and long terms being widely reported. In Reunion Island, the activity has rapidly developed, notably around a resident spinner dolphin population, which can be seen year-round. Focal follows revealed that the dolphins are less likely to begin socialising or resting and more likely to remain travelling or milling in the presence of dolphin-watching vessels. The dolphins' avoidance reactions increased when tourist vessels were numerous or in non-compliance with the regulations. The cumulative effect of such behavioural responses likely impacts the dolphins at the population level, highlighting the need for enforcing adaptive and efficient dolphin-watching management measures to ensure the welfare and preservation of the resident spinner dolphins of Reunion Island. Marine wildlife tourism has rapidly developed in Reunion Island, due to a large demand for interactions with a resident population of spinner dolphins (Stenella longirostris). The presence of dolphin-watching vessels close to dolphin groups can cause short-term impacts on their behaviour; cumulative incidences likely result in deleterious long-term impacts on the population. Using scan sampling, we collected behavioural data on spinner dolphins to evaluate the short-term effects of dolphin watching on their behaviour. The dolphins were less likely to begin socialising or diving while travelling and more likely to stay travelling and milling in the presence of vessels. Additionally, activity budgets for resting and socialising decreased simultaneously with increased travelling and milling. Avoidance responses significantly increased with an increase in the number of vessels and non-compliance with the local dolphin-watching guidelines. These behavioural responses are likely to have energetic costs for the dolphins, which may lead to decreased survival and reproductive success at individual and population levels. More restrictive regulations, increased surveillance and animal-based measures are key tools to adapt the conservation efforts in Reunion Island. Further studies on the island's resident dolphin populations are necessary to ensure the continuity of dolphin-watching activities in a sustainable manner. [ABSTRACT FROM AUTHOR]

Simple Summary: Multiple factors, both natural and anthropogenic, are driving most of the wild species to the verge of extinction across the globe. In order to conserve these threatened species, various conservation interventions and strategies are adopted, among which is re-introduction of captive stocks of species into the wild habitats where they vanished from. Captive breeding is one of the promising tools for endangered species preservation. Providing social enrichment to the captive stocks is an important step in the management, in particular for stocks, which are aimed for re-introduction. The subject species of this study, i.e., Punjab urial (Ovis vignei punjabiensis) and Indian gazelle (Gazella bennettii) are being reared in captivity with the aim of re-introduction. As there is scarcity of information regarding the behavioral aspects of captive species, especially ungulates, this study aimed at understanding the dynamics of their interactions. The current study reported that Punjab urial, being the dominant species, exerts itself on the submissive and subordinate species, the Indian gazelle. This negative interference can possibly lead to negative ramifications in the form of stress and injuries in the short term, while negative effects on population growth in the long term. Thus, this study recommends separate rearing of these species to eliminate the hazardous competition between them. Natural wildlife habitats are regularly subjected to anthropogenic pressures for different purposes, which are heading the biodiversity towards drastic decline. Several endangered wild species are raised in captivity with the aim of re-introduction. In some instances, mixed herds' rearing approach in captivity is adopted for providing social enrichment to captive stocks; however, the impacts of species on each other are least documented. We tested our prediction that keeping mixed herds of captive wild sheep and antelopes provides adequate social enrichment to the captive stocks: if interspecific interactions are balanced. In the current study, we studied the interspecific competition between mixed herds of captive Punjab urial (Ovis vignei punjabiensis) and Indian gazelle (Gazella bennettii) at Manglot Wildlife Park, Nowshera District, Khyber Pakhtunkhwa Province, Pakistan. We documented the negative effects of behavioural interference by Punjab urial on the feeding behaviour of Indian gazelle. The outcome of the current study revealed that Punjab urial are highly intolerant towards Indian gazelle, with high interference during feeding. Out of the total aggressive events, 77% (N = 1259) of events ended up with win/loss, in which Punjab urial dominated the Indian gazelle 3.5 times. Moreover, lopsided dominance by Punjab urial resulted in increased intraspecific competition among Indian gazelle (p < 0.001). Current study divulged Indian gazelle to be the subordinate species, with less intake of food. Instead of providing social enrichment by heterospecifics, the Punjab urial is negatively affecting the Indian gazelle, therefore, the results of our study discourage the practice of admix captive breeding for wild sheep and antelopes. [ABSTRACT FROM AUTHOR]

• Three bottlenose dolphins were asked to perform synchronised jumps in tandem. • While jumping in tandem, click trains were emitted by only one individual 98% of times. • The dolphins that do not vocalize are probably synchronising their jumps by eavesdropping the clicking dolphin. Synchronous behaviours occur when two or more animals display the same behaviour at the same time. However, the mechanisms underlying this synchrony are not well understood. In this study, we carried out an experiment to determine whether or not Bottlenose dolphins use acoustic cues when performing a known synchronised exercise. For this, we recorded three dolphins while they performed requested aerial jumps both individually or synchronously in pairs, with a hydrophone array and a 360° underwater video camera allowing the identification of the subject emitting vocalisations. Results indicated that in pairs, dolphins synchronised their jumps 100% of the time. Whether they jumped alone or in pairs, they produced click trains before and after 92% of jumps. No whistles or burst-pulsed sounds were emitted by the animals during the exercise. The acoustic localisation process allowed the successful identification of the vocalising subject in 19.8% of all cases (N = 141). Our study showed that in all (n = 28) but one successful localisations, the click trains were produced by the same individual. It is worth noting that this individual was the oldest female of the group. This paper provides evidence suggesting that during synchronous behaviours, dolphins use acoustic cues, and more particularly click trains, to coordinate their movements; possibly by eavesdropping on the clicks or echoes produced by one individual leading the navigation. [ABSTRACT FROM AUTHOR]

• Dolphin communication relies mainly in the acoustic channel. • The aim of this study was to determine if there was a correlation between the non-signature whistle production and the underwater behaviors of a group of bottlenose dolphins. • The occurrences of the six categories of whistles were highly collinear. • Non-signature whistle production was positively correlated with the time individuals spent slow swimming alone and negatively with the time spent in affiliative body contact. Bottlenose dolphins are social cetaceans that strongly rely on acoustic communication and signaling. The diversity of sounds emitted by the species has been structurally classified into whistles, clicks and burst-pulsed sounds. Although click sounds and individually-specific signature whistles have been largely studied, not much is known about non-signature whistles. Most studies that link behavior and whistle production conduct aerial behavioral observations and link the production of whistles to the general category of social interactions. The aim of this study was to determine if there was a correlation between the non-signature whistle production and the underwater behaviors of a group of bottlenose dolphins (Tursiops truncatus) under human care, during their free time in the absence of trainers. To do this we made audio-video recordings 15 min before and after 10 training sessions of eight dolphins in Boudewijn Seapark (Belgium). For the behavioral analysis we conducted focal follows on each individual based on six behavioral categories. For the acoustical analysis, carried out at the group level, we used the SIGID method to identify non-signature whistles (N = 661) and we classified them in six categories according to their frequency modulation. The occurrences of the six categories of whistles were highly collinear. Most importantly, non-signature whistle production was positively correlated with the time individuals spent slow swimming alone, and was negatively correlated with the time spent in affiliative body contact. This is the first analysis that links the production of non-signature whistles with particular underwater behaviors in this species. [ABSTRACT FROM AUTHOR]