132 research outputs found
Testing the anxiety reduction function of grooming interactions in wild Barbary macaques (Macaca sylvanus)
Get PDFTogether with its hygienic and social function, grooming is thought to reduce anxiety. However, empirical evidence on the anxiety-reduction function of grooming is scarce. We collected 10-minute focal data on the donor and recipient of grooming using the post-grooming / matchedcontrol
(PG-MC) method. In these PGs and MCs sessions, we recorded the occurrence of selfdirected behaviours (i.e. scratching and self-grooming), which are behavioural indicators of
anxiety. We found mixed evidence of the relationship between anxiety and grooming interactions. The link between grooming and anxiety may be more complex than originally
thought
The organization of collective group movements in wild Barbary macaques (Macaca sylvanus): social structure drives processes of group coordination in macaques
Get PDFSocial animals have to coordinate activities and collective movements to benefit from the advantages of group living.
Animals in large groups maintain cohesion by self-organization processes whereas in smaller groups consensus decisions
can be reached. Where consensus decisions are relevant leadership may emerge. Variation in the organization of collective
movements has been linked to variation in female social tolerance among macaque species ranging from despotic to
egalitarian. Here we investigated the processes underlying group movements in a wild macaque species characterized by a
degree of social tolerance intermediate to previously studied congeneric species. We focused on processes before, during
and after the departure of the first individual. To this end, we observed one group of wild Barbary macaques (Macaca
sylvanus) in the Middle Atlas, Morocco using all-occurrence behaviour sampling of 199 collective movements. We found that
initiators of a collective movement usually chose the direction in which more individuals displayed pre-departure behavior.
Dominant individuals contributed to group movements more than subordinates, especially juveniles, measured as
frequencies of successful initiations and pre-departure behaviour. Joining was determined by affiliative relationships and
the number of individuals that already joined the movement (mimetism). Thus, in our study group partially shared
consensus decisions mediated by selective mimetism seemed to be prevalent, overall supporting the suggestion that a
speciesâ social style affects the organization of group movements. As only the most tolerant species show equally shared
consensus decisions whereas in others the decision is partially shared with a bias to dominant individuals the type of
consensus decisions seems to follow a stepwise relation. Joining order may also follow a stepwise, however opposite,
relationship, because dominance only determined joining in highly despotic, but not in intermediate and tolerant species
Barbary Macaque Macaca sylvanus (Linnaeus, 1758)
Get PDFThis comprehensive species-specific chapter covers all aspects of the mammalian biology, including paleontology, physiology, genetics, reproduction and development, ecology, habitat, diet, mortality, and behavior. The economic significance and management of mammals and future challenges for research and conservation are addressed as well. The chapter includes a distribution map, a photograph of the animal, and a list of key literature
The effects of social network position on the survival of wild Barbary macaques, Macaca sylvanus
Get PDFIt has long been shown that the social environment of individuals can have strong effects on health, well-being, and longevity in a wide range of species. Several recent studies found that an individualâs number of affiliative partners positively relates to its probability of survival. Here, we build on these previous results to test how both affiliation and aggression networks predict Barbary macaque (Macaca sylvanus) survival in a ânatural experiment.â Thirty out of 47 wild Barbary macaques, living in 2 groups, died during an exceptionally cold winter in the Middle Atlas Mountains, Morocco. We analyzed the affiliation and aggression networks of both groups in the 6 months before the occurrences of these deaths, to assess which aspects of their social relationships enhanced individual survivorship. Using only the affiliation network, we found that network clustering was highly predictive of individual survival probability. Using
only the aggression network, we found that individual survival probability increased with a higher number of aggression partners and lower clustering coefficient. Interestingly, when both affiliation and aggression networks were considered together, only parameters from the aggression network were included into the best model predicting individual survival. Aggressive relationships might serve to stabilize affiliative social relationships, thereby positively impacting on individual survival during times of extreme weather conditions. Overall, our findings support the view that aggressive social interactions are extremely important for individual well-being and fitness
Experience-based human perception of facial expressions in Barbary macaques (Macaca sylvanus)
Get PDFBackground
Facial expressions convey key cues of human emotions, and may also be important for interspecies interactions. The universality hypothesis suggests that six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) should be expressed by similar facial expressions in close phylogenetic species such as humans and nonhuman primates. However, some facial expressions have been shown to differ in meaning between humans and nonhuman primates like macaques. This ambiguity in signalling emotion can lead to an increased risk of aggression and injuries for both humans and animals. This raises serious concerns for activities such as wildlife tourism where humans closely interact with wild animals. Understanding what factors (i.e., experience and type of emotion) affect ability to recognise emotional state of nonhuman primates, based on their facial expressions, can enable us to test the validity of the universality hypothesis, as well as reduce the risk of aggression and potential injuries in wildlife tourism.
Methods
The present study investigated whether different levels of experience of Barbary macaques, Macaca sylvanus, affect the ability to correctly assess different facial expressions related to aggressive, distressed, friendly or neutral states, using an online questionnaire. Participantsâ level of experience was defined as either: (1) naĂŻve: never worked with nonhuman primates and never or rarely encountered live Barbary macaques; (2) exposed: shown pictures of the different Barbary macaquesâ facial expressions along with the description and the corresponding emotion prior to undertaking the questionnaire; (3) expert: worked with Barbary macaques for at least two months.
Results
Experience with Barbary macaques was associated with better performance in judging their emotional state. Simple exposure to pictures of macaquesâ facial expressions improved the ability of inexperienced participants to better discriminate neutral and distressed faces, and a trend was found for aggressive faces. However, these participants, even when previously exposed to pictures, had difficulties in recognising aggressive, distressed and friendly faces above chance level.
Discussion
These results do not support the universality hypothesis as exposed and naĂŻve participants had difficulties in correctly identifying aggressive, distressed and friendly faces. Exposure to facial expressions improved their correct recognition. In addition, the findings suggest that providing simple exposure to 2D pictures (for example, information signs explaining animalsâ facial signalling in zoos or animal parks) is not a sufficient educational tool to reduce touristsâ misinterpretations of macaque emotion. Additional measures, such as keeping a safe distance between tourists and wild animals, as well as reinforcing learning via videos or supervised visits led by expert guides, could reduce such issues and improve both animal welfare and tourist experience
Assessing the Effects of Tourist Provisioning on the Health of Wild Barbary Macaques in Morocco
Get PDFFeeding wildlife is a very popular tourist activity, largely because it facilitates the close observation of animals in their natural habitat. Such provisioning may benefit animals by improving their survival and reproductive success, especially during periods of natural food shortage. However, provisioning by tourists may also have negative impacts on the health of the animals involved; to date such impacts are poorly understood. Here, we investigated the effects of tourist provisioning on the health of wild adult Barbary macaques, Macaca sylvanus, in Morocco. We compared health measures between a heavily provisioned group and a group that received negligible food from tourists and, in the former group, we also assessed health measures in relation to the intensity of provisioning. We used a broad range of non-invasive health measures relating to birth rate and survival, disease and injury risk, body size and condition, and physiological stress. Our findings indicate that feeding by tourists may overall have negative impacts on the health of Barbary macaques, being linked in particular to larger body size, elevated stress levels and more alopecia. Finally, we propose a framework to help consider the potential costs and benefits of provisioning, which may facilitate future research and management decisions on whetherâand how muchâprovisioning is acceptable
Primates' behavioural responses to tourists: evidence for a tradeoff between potential risks and benefits
Get PDFThe presence of, and interactions with tourists can be both risky and beneficial for wild animals. In wildlife tourism settings, animals often experience elevated rates of aggression from conspecifics, and they may also be threatened or physically aggressed by the tourists themselves. However, tourist provisioning of wild animals provides them with highly desirable foods. In situations of conflicting motivations such as this, animals would be expected to respond using behavioural coping mechanisms. In the present study, we investigated how animals respond to tourist pressure, using wild adult Barbary macaques in the Middle Atlas Mountains, Morocco, as a case study. We found evidence that these animals use a range of different behavioural coping mechanismsâphysical avoidance, social support, affiliative, aggressive and displacement behavioursâto cope with the stress associated with tourists. The pattern of use of such behaviours appears to depend on a trade-off between perceived risks and potential benefits. We propose a framework to describe how animals respond to conflicting motivational situations, such as the presence of tourists, that present simultaneously risks and benefits
Innovation in wild Barbary macaques (Macaca sylvanus)
Get PDFInnovation is the ability to solve novel problems or find novel solutions to familiar problems, and it is known to affect fitness in both human and non-human animals. In primates, innovation has been mostly studied in captivity, although differences in living conditions may affect individualsâ ability to innovate. Here, we tested innovation in a wild group of Barbary macaques (Macaca sylvanus). In four different conditions, we presented the group with several identical foraging boxes containing food. To understand which individual characteristics and behavioural strategies best predicted innovation rate, we measured the identity of the individuals manipulating the boxes and retrieving the food, and their behaviour during the task. Our results showed that success in the novel task was mainly affected by the experimental contingencies and the behavioural strategies used during the task. Individuals were more successful in the 1-step conditions, if they participated in more trials, showed little latency to approach the boxes and mainly manipulated functional parts of the box. In contrast, we found no effect of inhibition, social facilitation and individual characteristics like sex, age, rank, centrality, neophobia and reaction to humans, on the individualsâ ability to innovate
The functions of non-reproductive mounts among male Barbary macaques (Macaca sylvanus)
Get PDFSame-sex, non-reproductive mounts have been observed in a number of primate species and in various social contexts. However, the function of non-reproductive mounts is still largely unknown. We aimed to test whether non-reproductive mounts function to assert dominance and as appeasement behavior in male Barbary macaques. We analyzed post-mount behavior in fifty-four macaques belonging to two captive groups at Trentham Monkey Forest in Staffordshire, using 10-minute post-mount/matched-control focal sessions collected either on the mounter or the mountee. In support of the dominance assertion hypothesis, the higher-ranking male within a mounting pair was more likely to be the mounter than the mountee, and to mock bite the lower-ranking male. In support of the appeasement hypothesis, the former mounting partners were more likely to exchange grooming and to have a lower frequency of self-scratching (a measure of social tension) after a non-reproductive mount than in control sessions. Our study indicates that non-reproductive mounts have different and not mutually exclusive functions and can modulate the quality of social interactions among group members. We discuss the possible factors that can affect the occurrence of non-reproductive mounts within and between species
The effect of group size and individual characteristics on between-group encounters in primates
Get PDFBetween-group encounters are common in non-human primates and can vary from affiliative to aggressive. We extracted data from the literature to test five different hypotheses: 1) where there are group size differences between opposing groups, whether the larger group is more likely to win a between-group encounter than the smaller group; 2) whether the likelihood of a group engaging in aggressive between-group encounters increases with group size; and 3-5) whether dominant, older animals, and/or males are more likely to participate aggressively in between-group encounters than subordinate, younger animals and/or females. Our dataset comprised 52 studies on 31 primate species (3 lemur species, 5 New World monkeys, 19 Old World monkeys and 4 apes). We found that the larger group is more likely to win an encounter against a smaller group than vice-versa. We found no significant relationship between group size and propensity to be aggressive during between-group encounters. We found weak/no support for the effect of age, dominance rank and sex on the frequency of aggression displayed towards outgroup animals during between-group encounters. Species- and population-specific differences in between- and within-group competition and in the degree of the unequal distribution of resources across group members may explain why age, dominance rank and sex are not strong predictors of aggression during between-group encounters
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