Visual and acoustic exploratory behaviors toward novel stimuli in Antillean manatees (Trichechus manatus manatus) under human care.

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. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Cognition of the manatee: past research and future developments.

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.

Bottlenose dolphins' (Tursiops Truncatus) visual and motor laterality depending on emotional contexts.

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.