Thesis (M.S.)--Georgia Southern University, 2005. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science" ETD. Includes bibliographical references (p. 74-82) and appendices.

Most of what we know of the socioecology and behaviour of gorillas comes from studies of mountain gorillas (Gorilla beringei beringei), despite their representing less than 1% of all gorillas in the wild. Western lowland gorillas (Gorilla gorilla gorilla) have received far less research effort, and difficulties in habituation have led previous studies to rely heavily on indirect trail evidence. This has prevented any in-depth comparison of social structure and behaviour between species. The discovery of swampy clearings frequented by western lowland gorillas in northern Congo has offered the first opportunity to obtain accurate demographic and behavioural data. This thesis reports on 6273 hours of observer presence at Mbeli Bai, which yielded 1681 hours of direct gorilla observation. Most data come from a population of 13 groups and 7 solitary silverbacks. Group size ranged from 2 to 16 (mean = 8.4, SD 4.3) which does not differ significantly from data published on most other populations. Female natal and secondary transfer were recorded, and male emigration from the natal group appeared universal (no multi-silverback groups were recorded). No evidence of sub-grouping or a fission-fusion grouping pattern was found. During intra-group interactions, no evidence was recorded of female philopatry, and silverbacks herded and intimidated females (especially new immigrants) to prevent emigration. Inter-unit interactions took place on only 42% of shared bai-use occasions, and levels of silverback agonism were much lower than in mountain gorillas, with peaceful mingling of groups recorded. Display behaviour was common, and two previously unrecorded agonistic displays (the splash display and the crest display) are described. No contact aggression between silverbacks was observed but evidence of wounding sustained in the forest suggests that the bai environment may inhibit such aggression. High visibility and the ease of silverback 'policing' are thought to create an unusually tolerant social dynamic, and as such, frequencies of certain social behaviours should probably be viewed as site-specific. The thesis offers the fullest account of western gorilla social structure and behaviour to date. Long-term monitoring of life history variables, if continued, will provide an unparalleled opportunity to understand the effects of habitat and food availability and more stochastic influences on western gorilla social structure, fitness, and survival.

No description available.

Personality is defined as inter-individual variation of behavioral traits while maintaining intra-individual stability. The focus of this study was to observe distinct personality trait categories, establish baseline personality trait phenotypes for the juvenile population, and compare the personality phenotypes between different categories, such as sex or generation. Three personality traits were studied—sociability, curiousity, and boldness—based on the percentage of time individuals spent with conspecifics, human researchers, and their mothers, respectively. The surveyed individuals significantly varied positively and negatively from the means of each trait, and no significant difference for any trait was found between males and females, or across time periods. A moderately strong correlation was discovered between two personality traits, boldness and curiousity, suggesting a personality syndrome. The second primary goal was to use the aforementioned baseline to determine if personality traits can be used to predict neophilic behavior specific to human-dolphin communication research. Six of the study subjects were more prone than their peers to engage with the two-way work, and these individuals were more bold—spent less time with their mothers—than the other subjects. This suggests that boldness has some predictive capabilities towards this type of neophilia. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Grooming relationships between adult male chimpanzees are often reciprocal, i.e. individuals receive grooming from those they groom. Grooming may be reciprocated at the same time it is received (mutual grooming), or later within the same grooming session. Alternatively, it can be reciprocated at a much later stage, in another session. An analysis of individual grooming sessions at the dyadic level was used to investigate how chimpanzees reciprocate grooming within these sessions. This study describes the grooming and reciprocation of grooming by male chimpanzees, living in a multi-male, multi-female group at the Edinburgh Zoo, Scotland. A method for the analysis of dyadic grooming relationships was based on the presence or absence of mutual and unilateral grooming in a session, which allows seven types of grooming session to be distinguished. Grooming session was defined empirically, and the duration of the bout criterion interval (BCl) depended on the presence or absence of oestrous females. For comparison, however, the same BCI was used throughout. Without oestrous females, grooming was primarily reciprocated in sessions with mutual grooming and unilateral grooming by both participants. This kind of session proved highly cooperative and each male adjusted the duration of his unilateral grooming to that of mutual grooming, rather than to the duration of unilateral grooming by the other male. Mutual grooming was less important to dyads which had a strong grooming relationship. It is suggested that mutual grooming serves as an indication of the motivation to groom unilaterally. There was no indication that males reciprocated on the basis of TIT-FOR-TAT within these sessions, or between sessions in general. Alternative hypotheses of mutual grooming were only partly confirmed in that some dyads used mutual grooming to reduce the (already very short) time they spent in grooming. However, mutual grooming did not arise from the accidental overlap in the grooming of two partners. In the presence of oestrous females, grooming cooperation between the males broke down, and this was the result of heightened aggression as well as the presence of oestrous females itself. The balance in grooming given and received shifted in the direction of dominants (i.e. dominants received more) under the influence of oestrous females, but in the opposite direction under the influence of aggression. Feeding had no effect on the reciprocity of groormng. There was considerable dyadic variation. Some dyads groomed more when there were oestrous females, others groomed less. Some dyads had proportionally less mutual grooming with increasing numbers of oestrous females, others had more. There were generally no clear patterns of grooming reciprocation over longer time-spans than the session, but the overall degree of reciprocity of a dyad was frequently reached at the end of each day. Tracing the degree of reciprocation over a few weeks indicated that some dyads' grooming was governed by dominance, whereas that of others by cooperation.

Thesis (M.Sc. Biological Sciences)--University of Waikato, 2007. / Title from PDF cover (viewed February 21, 2008) Includes bibliographical references (p. 79-85)

Chez de nombreuses espèces, il a été montré que les stratégies de choix de partenaires socio-sexuels par un individu étaient liées aux qualités de ces partenaires (phénotypiques ou génétiques) et étaient susceptibles de maximiser la qualité de ses descendants et améliorer sa propre valeur adaptative. Nous nous sommes intéressés au choix de partenaires chez les femelles de gorille de plaines de l’ouest par une étude de leur dispersion sociale en lien avec l’influence relative de l’environnement social et des caractéristiques des mâles adultes dans les décisions des femelles à résider dans un groupe social ou à émigrer, et dans leur choix du groupe dans lequel immigrer. Nous avons montré que les femelles immigrent préférentiellement dans des groupes reproducteurs plutôt que vers des mâles solitaires et vers des groupes jeunes plutôt que vieillissants. Les groupes de 10-15 individus sont évités. Les femelles émigrent des groupes contenant une grande proportion d’individus affectés par une maladie de peau. A court terme après un effondrement démographique du à une épidémie à virus Ebola, le taux d’émigration des femelles diminue dans les groupes de grande taille, ce qui suggère une meilleure qualité reproductrice et protectrice des mâles survivants. Les caractéristiques génétiques des partenaires sexuels dans le choix des femelles, notamment les gènes du complexe majeur d’histocompatibilité (CMH) qui codent pour des protéines impliquées dans les défenses immunitaires, peuvent être impliquées dans le choix de partenaire chez certains primates. Son implication éventuelle n’avait jamais été étudiée chez le gorille. Dans cette perspective nous avons cherché à développer une méthode pour étudier ce complexe de gènes à partir d’échantillons d’ADN non invasifs (fèces), c’est-à-dire avec de l’ADN faiblement concentré et dégradé. Nous avons défini une nouvelle amorce puis utilisé des méthodes de séquençage haut débit, d’électrophorèse sur gel à gradient dénaturant et un marqueur microsatellite lié au CMH afin de déterminer une méthode d’analyse à l’échelle populationnelle. Huit nouveaux allèles de CMH ont été détectés par séquençage haut débit. Le marqueur microsatellite présente un schéma d’amplification complexe et nécessite une optimisation des protocoles qui permettra de réduire les couts d’analyses de la variabilité du CMH à l’échelle populationnelle. Nos développements ouvrent de nouvelles perspectives pour l’étude de l’influence du CMH sur le choix de partenaire dans des populations sauvages de primates. / In many species, it has been shown that strategies of choice of socio-sexual partners by an individual are related to the phenotypic or genetic quality of these partners and are likely to maximize the quality of its descendants and improve its own fitness. We investigated the partner choice in western lowland gorilla females in studying their social dispersion and the relative influence of the social environment and the characteristics of adult males in females’ decisions, to stay in a social group or to emigrate, and in their choice of the group into which immigrate. We showed that females preferentially migrated towards breeding groups rather than solitary males and towards younger rather than aging groups. Groups of 10-15 individuals were avoided. Females emigrated from groups containing a large proportion of individuals affected by skin disease. In the short term after a demographic die-off due to an Ebola epidemic, female’s emigration rates declined in large groups, suggesting better reproductive and protective value of surviving males. The influence of the genetic characteristics of the sexual partners in the choice of females, in particular the genes of the major histocompatibility complex (MHC) genes that encode proteins involved in immune defenses, may be involved in partner choice in some primates. Its possible involvement had never been studied in the gorilla. In this perspective we have sought to develop a method to study this gene complex from non-invasive DNA samples (feces), that is to say with weakly concentrated and degraded DNA. We defined a new primer and then used high throughput sequencing, denaturing gradient gel electrophoresis, and a MHC-linked microsatellite marker to determine a population-level analysis method. Eight new MHC alleles were detected by high throughput sequencing. The microsatellite marker has a complex amplification pattern and requires protocol optimization that will reduce the cost of analyzing MHC variability at the population level. Our developments open new perspectives for the study of the influence of CMH on partner choice in wild populations of primates.

La vie en groupe fascine les scientifiques depuis longtemps et la question des mécanismes en jeu permettant à un groupe social de rester cohésif est largement étudiée. Dans ce travail, je me suis intéressée à l’implication des relations sociales dans le maintien de la cohésion chez trois espèces de Cercopithecinae. Pourquoi certains individus occupent une place particulière au sein du réseau de relations sociales d’un groupe ?Ces individus ayant un statut social particulier ont-ils un rôle de ciment social ?D’après les résultats de ce travail, les relations de parenté, en relation avec le style social de l’espèce, semblent être le facteur prédominant sous-tendant l’accession des individus à un statut social élevé. De plus, les individus occupant une position sociale élevée jouent un rôle primordial dans la stabilité du groupe, et ont également une influence importante sur les décisions prises quotidiennement, leur conférant in fine un avantage en termes de survie et de reproduction./The comprehension of the mechanisms allowing a social group to stay cohesive throughout their environment and across seasons is a fascinating question. In this work, I studied the implication of social relationships in maintaining group cohesion in three Cercopithecinae species. Why some individuals occupy specific positions within the social relationships network? Have these individuals a particular role in the stability of social groups? According to our results, kinship seems to be an important variable underlying the access to a high social status for group members, in respect with the social style displayed by the considered species. Moreover, Individuals occupying such high social positions play a crucial role for the group stability. They also have a great influence on decisions took on a daily basis by the group. This high social status is therefore advantageous for individuals in terms of survival and reproduction. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Narrow riparian woodlands along non-perennial streams have made it possible for vervet monkeys to penetrate the semi-arid karoo ecosystem of South Africa, while artificial water points have more recently allowed these populations to colonize much more marginal habitat away from natural water sources. In order to determine the sequelae of life in these narrow, linear woodlands for historically 'natural' populations, I determined the size of troops in relation to their reliance on natural and artificial water sources and collected detailed data from two river-centred troops on activity, diet and ranging behaviour over an annual cycle. These data indicate that river-centred troops were distinctive primarily for their large group sizes and, consequently, their large adult cohorts, and the extent of home range overlap in what is regarded as a territorial species. While large group size carried the corollary of increased day journey length and longer estimated interbirth intervals, there was little other indication of ecological stress. Specifically, the rate of predation appears to be lower than observed at other sites. Predation encounters here, encourage the use of predator vigilance rather than influencing the use of space within the habitat. The high density of Acacia karoo, which accounted for a third of annual foraging effort in what was a relatively depauperate floristic habitat, allows for an adequate energy intake for groups of this size. I ascribed the large group size and home range overlap to the inability of groups to undergo fission. / xiii, 79 leaves : ill., maps ; 29 cm

Vivre en groupe implique une cohésion et une synchronisation des activités des membres d’un groupe. Dans ce contexte, des individus avec des besoins pouvant être différents doivent décider conjointement où et quand se déplacer collectivement. Alors que les comportements de recrutement et de vote ont été relativement bien étudiés chez les primates et que les processus auto-organisés ont été démontrés dans des grands groupes, peu de chercheurs ont étudié l’existence de processus simples dans des petits groupes structurés d’individus aux capacités cognitives avancées. De même, alors qu’il a été démontré que les relations sociales d’une espèce conditionnaient la forme de certains comportements tels que les comportements d’agression, de réconciliation ou de toilettage, aucune étude n’a démontré cette influence sur le type de consensus d’une espèce. Afin de tester ces différentes hypothèses, j’ai étudié deux espèces de macaques au style social contrasté, le macaque rhésus (Macaca mulatta) ayant une hiérarchie stricte et un népotisme élevé et le macaque de Tonkean (M. tonkeana) connu pour être tolérant. Les résultats de cette thèse montrent donc l’existence conjointe de processus auto-organisés et de processus plus complexes et intentionnels chez les macaques. Ils démontrent également l’influence du système social sur la prise de décision collective, en termes de dominance et de parenté. Le macaque de Tonkean présente un consensus équitablement partagé et les membres du groupe s’organisent au sein du déplacement en fonction des relations affiliatives, contrairement au macaque rhésus pour lequel le consensus ne semble que partiellement partagé, en faveur des individus dominants et l’organisation des individus biaisée en faveur de la parenté. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished