Female philopatry and dominance patterns in wild geladas

Cercopithecines have a highly conserved social structure with strong female bonds and stable, maternally inherited linear dominance hierarchies. This system has been ascribed to the pervasiveness of female philopatry within the typical multi-male, multi-female social groups. We examined the relationship between female philopatry, dominance hierarchies, and reproduction in geladas ( Theropithecus gelada ), a species with an unusual multi-leveled society. During a 4-year field study on a wild population in the Simien Mountains National Park, Ethiopia, we observed 14 units across two bands of geladas that underwent a number of events, such as male takeovers and female deaths, which could potentially disrupt female relationships and unit structure. First, we corroborate earlier reports that gelada females are natally philopatric: we observed no interunit migrations, and the female mortality rate was comparable to that of philopatric baboons (suggesting all female disappearances were indeed deaths). Second, contrary to previous reports, data from this long-term study show that geladas exhibit the linear and stable dominance hierarchies typical of other Cercopithecines. Moreover, female ranks appear to be maternally inherited. Third, we found no evidence that alpha females aggressively target the lowest ranking individuals, nor did rank confer clear reproductive advantages to dominant females within our 4-year observation period. As such, geladas fit the allostatic load model [Goymann & Wingfield, Animal Behaviour 67:591–602, 2004]. Our study confirms the importance of female philopatry in the kin-based Cercopithecine dominance system. Am. J. Primatol. 73:422–430, 2011. © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83472/1/20916_ftp.pd

Ecology eclipses phylogeny as a major driver of nematode parasite community structure in a graminivorous primate

Understanding how ecology and phylogeny shape parasite communities can inform parasite control and wildlife conservation initiatives while contributing to the study of host species evolution.We tested the relative strengths of phylogeny and ecology in driving parasite community structure in a host whose ecology diverges significantly from that of its closest phylogenetic relatives.We characterized the gastrointestinal (GI) parasite community of wild geladas Theropithecus gelada, primates that are closely related to baboons but specialized to graminovory in the Ethiopian Highlands.Geladas exhibited very constrained GI parasite communities: only two genera (Oesophagostomum and Trichostrongylus) were identified across 305 samples. This is far below the diversity reported for baboons (Papio spp.) and at the low end of the range of domestic grazers (e.g. Bos taurus, Ovis aries) inhabiting the same region and ecological niche.Using deep amplicon sequencing, we identified 15 amplicon sequence variants (ASVs) within the two genera, seven of which matched to Oesophagostomum sp., seven to Trichostrongylus sp., and one to T. vitrinus.Population was an important predictor of ASV richness. Geladas in the most ecologically disturbed area of the national park exhibited approximately four times higher ASV richness than geladas at a less disturbed location within the park.In this system, ecology was a stronger predictor of parasite community structure than was phylogeny, with geladas sharing more elements of their parasite communities with other grazers in the same area than with closely related sister taxa.A free Plain Language Summary can be found within the Supporting Information of this article.A free Plain Language Summary can be found within the Supporting Information of this article.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/3/fec13603_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/2/fec13603.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162742/1/fec13603-sup-0001-Summary.pd

Identifying wildlife reservoirs of neglected taeniid tapeworms : non-invasive diagnosis of endemic Taenia serialis infection in a wild primate population

Despite the global distribution and public health consequences of Taenia tapeworms, the life cycles of taeniids infecting wildlife hosts remain largely undescribed. The larval stage of Taenia serialis commonly parasitizes rodents and lagomorphs, but has been reported in a wide range of hosts that includes geladas (Theropithecus gelada), primates endemic to Ethiopia. Geladas exhibit protuberant larval cysts indicative of advanced T. serialis infection that are associated with high mortality. However, non-protuberant larvae can develop in deep tissue or the abdominal cavity, leading to underestimates of prevalence based solely on observable cysts. We adapted a non-invasive monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) to detect circulating Taenia spp. antigen in dried gelada urine. Analysis revealed that this assay was highly accurate in detecting Taenia antigen, with 98.4% specificity, 98.5% sensitivity, and an area under the curve of 0.99. We used this assay to investigate the prevalence of T. serialis infection in a wild gelada population, finding that infection is substantially more widespread than the occurrence of visible T. serialis cysts (16.4% tested positive at least once, while only 6% of the same population exhibited cysts). We examined whether age or sex predicted T. serialis infection as indicated by external cysts and antigen presence. Contrary to the female-bias observed in many Taenia-host systems, we found no significant sex bias in either cyst presence or antigen presence. Age, on the other hand, predicted cyst presence (older individuals were more likely to show cysts) but not antigen presence. We interpret this finding to indicate that T. serialis may infect individuals early in life but only result in visible disease later in life. This is the first application of an antigen ELISA to the study of larval Taenia infection in wildlife, opening the doors to the identification and description of infection dynamics in reservoir populations

Alouatta pigra males ignore A. palliata loud calls: A case of failed rival recognition?

ObjectivesWhen closely related species overlap geographically, selection may favor speciesâ specific mate recognition traits to avoid hybridization costs. Conversely, the need to recognize potential sameâ sex rivals may select for lower specificity, creating the possibility that selection in one domain constrains evolution in the other. Despite a wealth of data on mate recognition, studies addressing rival recognition between hybridizing species are limited to a few bird species. Using naïve populations, we examine the extent to which failed rival recognition might have affected hybridization patterns when two species of howler monkeys (Alouatta pigra and A. palliata) first met after diverging in allopatry.MethodsWe simulated first contact between naïve subjects using playback experiments in allopatric populations of the two purebred species. Using linear mixed models, we compared their look, move, and vocal responses to conspecific and heterospecific loud calls.ResultsAlthough not different in overall response strength to playbacks, the two species differed in reaction to heterospecific callers. Male A. pigra ignored calls from male A. palliata, but the reverse was not true.DiscussionDespite striking differences in vocalizations, A. palliata respond equally to calls from both species whereas A. pigra respond only to conspecifics. This apparent failure of A. pigra males to recognize interspecific rivals might have biased hybridization (F1 hybridsâ =â male A. palliata x female A. pigra), a pattern previously hypothesized based on genetic analysis of hybrids. Given that A. pigra males could be losing reproductive opportunities to heterospecific males, our findings add to growing evidence of potential costs for overly specific species recognition.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144221/1/ajpa23443.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144221/2/ajpa23443_am.pd

A simple method for measuring colour in wild animals: validation and use on chest patch colour in geladas ( Theropithecus gelada )

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72620/1/j.1095-8312.2008.00981.x.pd

Quantifying uncertainty due to fission-fusion dynamics as a component of social complexity.

Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggregations or subgroups come together and split, changing composition over short temporal scales, (i.e. fission and fusion). A high degree of fission-fusion dynamics may constrain the regulation of social relationships, introducing uncertainty in interactions between group members. Here we use Shannon's entropy to quantify the predictability of subgroup composition for three species known to differ in the way their subgroups come together and split over time: spider monkeys (Ateles geoffroyi), chimpanzees (Pan troglodytes) and geladas (Theropithecus gelada). We formulate a random expectation of entropy that considers subgroup size variation and sample size, against which the observed entropy in subgroup composition can be compared. Using the theory of set partitioning, we also develop a method to estimate the number of subgroups that the group is likely to be divided into, based on the composition and size of single focal subgroups. Our results indicate that Shannon's entropy and the estimated number of subgroups present at a given time provide quantitative metrics of uncertainty in the social environment (within which social relationships must be regulated) for groups with different degrees of fission-fusion dynamics. These metrics also represent an indirect quantification of the cognitive challenges posed by socially dynamic environments. Overall, our novel methodological approach provides new insight for understanding the evolution of social complexity and the mechanisms to cope with the uncertainty that results from fission-fusion dynamics

Female chacma baboons form strong, equitable, and enduring social bonds

Analyses of the pattern of associations, social interactions, coalitions, and aggression among chacma baboons (Papio hamadryas ursinus) in the Okavango Delta of Botswana over a 16-year period indicate that adult females form close, equitable, supportive, and enduring social relationships. They show strong and stable preferences for close kin, particularly their own mothers and daughters. Females also form strong attachments to unrelated females who are close to their own age and who are likely to be paternal half-sisters. Although absolute rates of aggression among kin are as high as rates of aggression among nonkin, females are more tolerant of close relatives than they are of others with whom they have comparable amounts of contact. These findings complement previous work which indicates that the strength of social bonds enhances the fitness of females in this population and support findings about the structure and function of social bonds in other primate groups

The structural and motivational role of the unique lip‐flip movement in the gelada (Theropithecus gelada) facial display repertoire

ObjectivesHuman language represents an extreme form of communicative complexity. Primate facial display complexity, which depends upon facial mobility, can be used as a model for the study of the evolution of communicative complexity. The gelada (Theropithecus gelada) is the only primate that can produce a lip‐flip eversion. This study investigates the role of the lip‐flip relative to the bared‐teeth display to understand its role in generating communicative complexity.Materials and methodsWe reviewed videos of gelada social interactions. We utilized the facial action coding system (FACS) to define structural component action units (AUs) of each display. We inferred display motivation from the behaviors of the display sender.ResultsThe lip‐flip was used only in combination with the essential AUs of the bared‐teeth display, serving as an optional structural element added to produce a structural variant. Both the bared‐teeth display with and without a lip‐flip occurred most frequently with nonaggressive, submissive behaviors. The lip‐flip was more frequently preceded by approach than the bared‐teeth display, especially in males. The lip‐flip was also present in the majority of structurally blended facial displays though the motivation of the non‐lip‐flip parent display often dominated.DiscussionThe lip‐flip may potentially function as an indicator of benign intent after an approach or as an intensifying component of nonaggressive intent. Adaptations to increase facial mobility in geladas via facilitating the lip‐flip may promote increased communicative complexity through increased conspicuousness and motivational signaling specification or intensification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155514/1/ajpa24031_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155514/2/ajpa24031.pd