The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Colin A. Chapman - One of the best experts on this subject based on the ideXlab platform.
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Infant Pelage Color Change and Infant Handling in Captive Black-and-White Colobus
Mammal Study, 2020Co-Authors: Taiki Okumura, Kei Nemoto, Colin A. Chapman, Ikki MatsudaAbstract:Colobine monkeys generally spend less time each day engaged in social interactions than other primates. However, a notable feature of their social interaction involves females exchanging infants (i.e., infant handling). Here, we report on the handling of an infant in relation to pelage color change in a group of Black-and-White Colobus (Colobus guereza) housed in the Japan Monkey Centre. We found large variation in the speed of infant pelage color change among body parts (range 100–216 days) and documented that infant handling by non-mothers was related to the infant pelage color and/or moving ability (infant independence). Non-mothers, especially females, were clearly attracted to the newborn infant and often handled the infant in a few weeks of its birth, but handling decreased with infant age and corresponded both with the loss of the natal coat color and the infant acquiring effective locomotory independence. We document interesting patterns, but the conclusions we can draw are limited and future research should consider separating effects of infant pelage color and infant locomotory independence and evaluate the effect of infant body mass.
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Group Size Dynamics over 15+ Years in an African Forest Primate Community
Biotropica, 2014Co-Authors: Jan F. Gogarten, Aerin L. Jacob, Ria R. Ghai, Jessica M. Rothman, Dennis Twinomugisha, Michael D. Wasserman, Colin A. ChapmanAbstract:Group size affects many aspects of the ecology and social organization of animals. We investigated group size stability for five primate species in Kibale National Park, Uganda from 1996 to 2011 at three nested spatial scales. Survey data indicated that group sizes did not change for most species, with the exception of red Colobus monkeys (ProColobus rufomitratus), in which group size increased at all spatial scales. Mangabey (Lophocebus albigena) group size increased in old-growth forest, but the sample size and increase were small. To augment this survey data, we collected several years of demographic data on three habituated groups of redtail monkeys (Cercopithecus ascanius), eight groups of Black-and-White Colobus (Colobus guereza), and one red Colobus group. The red Colobus group increased from 59 to 104 individuals, while redtail monkey and Black-and-White Colobus group sizes were stable, mirroring our survey results. To understand mechanisms behind group size changes in red Colobus versus stability in other primates, we monitored forest dynamics at two spatial scales between 1990 and 2013, considered changes in predator population, and explored evidence of disease dynamics. The cumulative size of all trees and red Colobus food trees increased over 24 yr, suggesting that changing food availability was driving group size changes for red Colobus, while predation and disease played lesser roles. Overall, our results and evidence of changing primate densities suggest that the Kibale primate community is in a non-equilibrium state. We suggest future conservation and management efforts take this into consideration.
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fecal microbiomes of non human primates in western uganda reveal species specific communities largely resistant to habitat perturbation
American Journal of Primatology, 2014Co-Authors: Aleia I Mccord, Colin A. Chapman, David Hyeroba, Alex Tumukunde, Geoffrey Weny, Kelly Klotz, Avery S Koblings, David N M Mbora, Melissa A CreggerAbstract:Primate gastrointestinal microbial communities are becoming increasingly appreciated for their relevance to comparative medicine and conservation, but the factors that structure primate “microbiomes” remain controversial. This study examined a community of primates in Kibale National Park, Uganda, to assess the relative importance of host species and location in structuring gastrointestinal microbiomes. Fecal samples were collected from primates in intact forest and from primates in highly disturbed forest fragments. People and livestock living nearby were also included, as was a geographically distant population of related red Colobus in Kenya. A culture-free microbial community fingerprinting technique was used to analyze fecal microbiomes from 124 individual red Colobus (ProColobus rufomitratus), 100 individual Black-and-White Colobus (Colobus guereza), 111 individual red-tailed guenons (Cercopithecus ascanius), 578 human volunteers, and 364 domestic animals, including cattle (Bos indicus and B. indicus × B. taurus crosses), goats (Caprus hircus), sheep (Ovis aries), and pigs (Sus scrofa). Microbiomes sorted strongly by host species, and forest fragmentation did not alter this pattern. Microbiomes of Kenyan red Colobus sorted distinctly from microbiomes of Ugandan red Colobus, but microbiomes from these two red Colobus populations clustered more closely with each other than with any other species. Microbiomes from red Colobus and Black-and-White Colobus were more differentiated than would be predicted by the phylogenetic relatedness of these two species, perhaps reflecting heretofore underappreciated differences in digestive physiology between the species. Within Kibale, social group membership influenced intra-specific variation among microbiomes. However, intra-specific variation was higher among primates in forest fragments than among primates in intact forest, perhaps reflecting the physical separation of fragments. These results suggest that, in this system, species-specific processes such as gastrointestinal physiology strongly structure microbial communities, and that primate microbiomes are relatively resistant to perturbation, even across large geographic distances or in the face of habitat disturbance.
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RESEARCH ARTICLE Fecal Microbiomes of Non-Human Primates in Western Uganda Reveal Species-Specific Communities Largely Resistant to Habitat Perturbation
2014Co-Authors: Aleia I Mccord, Colin A. Chapman, David Hyeroba, Alex Tumukunde, Geoffrey Weny, Kelly Klotz, Avery S Koblings, Melissa A Cregger, Bryan A. White, Steven R. LeighAbstract:Primate gastrointestinal microbial communities are becoming increasingly appreciated for their relevance to comparative medicine and conservation, but the factors that structure primate “microbiomes” remain controversial. This study examined a community of primates in Kibale National Park, Uganda, to assess the relative importance of host species and location in structuring gastrointestinal microbiomes. Fecal samples were collected from primates in intact forest and from primates in highly disturbed forest fragments. People and livestock living nearby were also included, as was a geographically distant population of related red Colobus in Kenya. A culture‐free microbial community fingerprinting technique was used to analyze fecal microbiomes from 124 individual red Colobus (ProColobus rufomitratus), 100 individual black‐and‐white Colobus (Colobus guereza), 111 individual red‐tailed guenons (Cercopithecus ascanius), 578 human volunteers, and 364 domestic
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Fecal microbiomes of non‐human primates in Western Uganda reveal species‐specific communities largely resistant to habitat perturbation
American journal of primatology, 2013Co-Authors: Aleia I Mccord, Colin A. Chapman, David Hyeroba, Alex Tumukunde, Geoffrey Weny, Kelly Klotz, Avery S Koblings, David N M Mbora, Melissa A Cregger, Bryan A. WhiteAbstract:Primate gastrointestinal microbial communities are becoming increasingly appreciated for their relevance to comparative medicine and conservation, but the factors that structure primate “microbiomes” remain controversial. This study examined a community of primates in Kibale National Park, Uganda, to assess the relative importance of host species and location in structuring gastrointestinal microbiomes. Fecal samples were collected from primates in intact forest and from primates in highly disturbed forest fragments. People and livestock living nearby were also included, as was a geographically distant population of related red Colobus in Kenya. A culture-free microbial community fingerprinting technique was used to analyze fecal microbiomes from 124 individual red Colobus (ProColobus rufomitratus), 100 individual Black-and-White Colobus (Colobus guereza), 111 individual red-tailed guenons (Cercopithecus ascanius), 578 human volunteers, and 364 domestic animals, including cattle (Bos indicus and B. indicus × B. taurus crosses), goats (Caprus hircus), sheep (Ovis aries), and pigs (Sus scrofa). Microbiomes sorted strongly by host species, and forest fragmentation did not alter this pattern. Microbiomes of Kenyan red Colobus sorted distinctly from microbiomes of Ugandan red Colobus, but microbiomes from these two red Colobus populations clustered more closely with each other than with any other species. Microbiomes from red Colobus and Black-and-White Colobus were more differentiated than would be predicted by the phylogenetic relatedness of these two species, perhaps reflecting heretofore underappreciated differences in digestive physiology between the species. Within Kibale, social group membership influenced intra-specific variation among microbiomes. However, intra-specific variation was higher among primates in forest fragments than among primates in intact forest, perhaps reflecting the physical separation of fragments. These results suggest that, in this system, species-specific processes such as gastrointestinal physiology strongly structure microbial communities, and that primate microbiomes are relatively resistant to perturbation, even across large geographic distances or in the face of habitat disturbance.
Pascale Sicotte - One of the best experts on this subject based on the ideXlab platform.
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Divergence in gut microbial communities mirrors a social group fission event in a Black-and-White Colobus monkey (Colobus vellerosus).
American journal of primatology, 2019Co-Authors: Claire K. Goodfellow, Eva C. Wikberg, Pascale Sicotte, Tabor Whitney, Diana Christie, Pascale Sicotte, Eva C. Wikberg, Nelson Ting, Claire K. Goodfellow, Tabor Whitney, Diana Christie, Nelson TingAbstract:Host behavior and social factors have increasingly been implicated in structuring the composition of gut microbial communities. In social animals, distinct microbial communities characterize different social groups across a variety of taxa, although little longitudinal research has been conducted that demonstrates how this divergence occurs. Our study addresses this question by characterizing the gut microbial composition of an African Old World monkey, the Black-and-White Colobus (Colobus vellerosus), before and after a social group fission event. Gut microbial taxonomic composition of these monkeys was profiled using the V-4 hypervariable region of the bacterial 16S ribosomal RNA gene, and pairwise-relatedness values were calculated for all individuals using 17 short tandem repeat loci and partial pedigree information. The two social groups in this study were found to harbor distinct microbial signatures after the fission event from which they emerged, while these communities were not divergent in the same individuals before this event. Three genera were found to differ in abundance between the two new social groups: Parabacteroides, Coprococcus, and Porphyromonadaceae. Additionally, although this fission happened partially along lines of relatedness, relatedness did not structure the differences that we found. Taken together, this study suggests that distinct gut microbial profiles can emerge in social groups in
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Divergence in gut microbial communities mirrors a social group fission event in a Black-and-White Colobus monkey (Colobus vellerosus)
2019Co-Authors: Claire K. Goodfellow, Eva C. Wikberg, Pascale Sicotte, Tabor Whitney, Diana Christie, Pascale Sicotte, Eva C. Wikberg, Nelson Ting, Claire K. Goodfellow, Tabor Whitney, Diana Christie, Nelson TingAbstract:Host behavior and social factors have increasingly been implicated in structuring the composition of gut microbial communities. In social animals, distinct microbial communities characterize different social groups across a variety of taxa, although little longitudinal research has been conducted that demonstrates how this divergence occurs. Our study addresses this question by characterizing the gut microbial composition of an African Old World monkey, the Black-and-White Colobus (Colobus vellerosus), prior to and after a social group fission event. Gut microbial taxonomic composition of these monkeys was profiled using the V-4 hypervariable region of the bacterial 16s rRNA gene, and pairwise-relatedness values were calculated for all individuals using 17 STR loci and partial pedigree information. The two social groups in this study were found to harbor distinct microbial signatures after the fission event from which they emerged, while these communities were not divergent in the same individuals prior to this event. Furthermore, although this fission happened partially along lines of relatedness, relatedness did not structure the differences that we found. Taken together, this study suggests that distinct gut microbial profiles can emerge in social groups in less than one year and recommends further work into more finely mapping the timescales, causes, and potentially adaptive effects of this recurring trend toward distinct group microbial signatures.
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Individualistic female dominance hierarchies with varying strength in a highly folivorous population of Black-and-White Colobus
Behaviour, 2013Co-Authors: Eva C. Wikberg, Julie A. Teichroeb, Iulia B, Pascale SicotteAbstract:Females that do not experience strong contest competition for food are presumed to form ‘egalitarian’ relationships (i.e., lacking strong, linear dominance hierarchies). However, recent studies of Gorilla beringei beringei (mountain gorilla) have documented relatively strong, linear female dominance hierarchies despite them having a highly folivorous diet that generates relatively low levels of within-group contest competition (Robbins et al., 2005, 2007). To investigate if this pattern holds true for other highly folivorous species that may experience low levels of contest competition, we examined the linearity and strength of female dominance hierarchies in a population of Colobus vellerosus (ursine Colobus or white-thighed Colobus) at Boabeng-Fiema, Ghana. From 2004 to 2011, we collected data via ad libitum and focal sampling of 75 adult and subadult females in eight groups. Half of the study groups had few unknown submissive relationships, and females formed individualistic hierarchies with high linearity indices ranging from 0.9 to 1. There was between-group variation in all components of hierarchical strength (i.e., hierarchical expression, consistency, and stability). Groups showed varying rates of submission, and there was a short latency to detect a linear hierarchy in some groups and a long latency in other groups (i.e., varying levels of hierarchical expression). Females in most groups formed unidirectional and stable relationships. Maturing females challenged older females in some groups, and these groups had more non-linear relationships (i.e., dyads with more submissive interactions down rather than up the hierarchy) and higher rates of individual rank change than other groups. Based on low rates of submission, long latencies, and/or some inconsistencies, we conclude that most groups form relatively
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Between-group variation in female dispersal, kin composition of groups, and proximity patterns in a Black-and-White Colobus monkey (Colobus vellerosus).
PloS one, 2012Co-Authors: Eva C. Wikberg, Pascale Sicotte, Fernando A. Campos, Nelson TingAbstract:A growing body of evidence shows within-population variation in natal dispersal, but the effects of such variation on social relationships and the kin composition of groups remain poorly understood. We investigate the link between dispersal, the kin composition of groups, and proximity patterns in a population of Black-and-White Colobus (Colobus vellerosus) that shows variation in female dispersal. From 2006 to 2011, we collected behavioral data, demographic data, and fecal samples of 77 males and 92 females residing in eight groups at Boabeng-Fiema, Ghana. A combination of demographic data and a genetic network analysis showed that although philopatry was female-biased, only about half of the females resided in their natal groups. Only one group contained female-female dyads with higher average relatedness than randomly drawn animals of both sexes from the same group. Despite between-group variation in female dispersal and kin composition, female-female dyads in most of the study groups had higher proximity scores than randomly drawn dyads from the same group. We conclude that groups fall along a continuum from female dispersed, not kin-based, and not bonded to female philopatric, kin-based, and bonded. We found only partial support for the predicted link between dispersal, kin composition, and social relationships. In contrast to most mammals where the kin composition of groups is a good predictor of the quality of female-female relationships, this study provides further support for the notion that kinship is not necessary for the development and maintenance of social bonds in some gregarious species.
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Traditional taboos in biological conservation: the case of Colobus vellerosus at the Boabeng-Fiema Monkey Sanctuary, Central Ghana
Social Science Information, 2006Co-Authors: Tania L. Saj, Charles Mather, Pascale SicotteAbstract:EnglilishThe Boabeng-Fiema Monkey Sanctuary in central Ghana has been called a classic example of successful ‘‘traditional’’ conservation. Local hunting taboos on two species of primates (the ursine black and white Colobus and the Campbell's monkey) are thought to date back to the 1830s when a local oracle instructed the villagers to ‘‘care for the monkeys’’. However, the same level of protection is not given to the surrounding forest or other animals in the forest. In light of this situation, we examine the extent to which the traditional taboos on the monkeys complement the biological/ environmental conservation agenda. We come to the conclusion that the monkeys embody the history and foundation myths of the villages and serve as a totemic mechanism to preserve the villagers' social world.FrenchLe "Boabeng-Fiema Monkey Sanctuary'' au centre du Ghana est considere comme un exemple classique de conservation "traditionnelle'' reussie. Les tabous locaux sur la chasse de deux especes de primates (le Colobus ...
Nelson Ting - One of the best experts on this subject based on the ideXlab platform.
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Divergence in gut microbial communities mirrors a social group fission event in a Black-and-White Colobus monkey (Colobus vellerosus).
American journal of primatology, 2019Co-Authors: Claire K. Goodfellow, Eva C. Wikberg, Pascale Sicotte, Tabor Whitney, Diana Christie, Pascale Sicotte, Eva C. Wikberg, Nelson Ting, Claire K. Goodfellow, Tabor Whitney, Diana Christie, Nelson TingAbstract:Host behavior and social factors have increasingly been implicated in structuring the composition of gut microbial communities. In social animals, distinct microbial communities characterize different social groups across a variety of taxa, although little longitudinal research has been conducted that demonstrates how this divergence occurs. Our study addresses this question by characterizing the gut microbial composition of an African Old World monkey, the Black-and-White Colobus (Colobus vellerosus), before and after a social group fission event. Gut microbial taxonomic composition of these monkeys was profiled using the V-4 hypervariable region of the bacterial 16S ribosomal RNA gene, and pairwise-relatedness values were calculated for all individuals using 17 short tandem repeat loci and partial pedigree information. The two social groups in this study were found to harbor distinct microbial signatures after the fission event from which they emerged, while these communities were not divergent in the same individuals before this event. Three genera were found to differ in abundance between the two new social groups: Parabacteroides, Coprococcus, and Porphyromonadaceae. Additionally, although this fission happened partially along lines of relatedness, relatedness did not structure the differences that we found. Taken together, this study suggests that distinct gut microbial profiles can emerge in social groups in
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Divergence in gut microbial communities mirrors a social group fission event in a Black-and-White Colobus monkey (Colobus vellerosus)
2019Co-Authors: Claire K. Goodfellow, Eva C. Wikberg, Pascale Sicotte, Tabor Whitney, Diana Christie, Pascale Sicotte, Eva C. Wikberg, Nelson Ting, Claire K. Goodfellow, Tabor Whitney, Diana Christie, Nelson TingAbstract:Host behavior and social factors have increasingly been implicated in structuring the composition of gut microbial communities. In social animals, distinct microbial communities characterize different social groups across a variety of taxa, although little longitudinal research has been conducted that demonstrates how this divergence occurs. Our study addresses this question by characterizing the gut microbial composition of an African Old World monkey, the Black-and-White Colobus (Colobus vellerosus), prior to and after a social group fission event. Gut microbial taxonomic composition of these monkeys was profiled using the V-4 hypervariable region of the bacterial 16s rRNA gene, and pairwise-relatedness values were calculated for all individuals using 17 STR loci and partial pedigree information. The two social groups in this study were found to harbor distinct microbial signatures after the fission event from which they emerged, while these communities were not divergent in the same individuals prior to this event. Furthermore, although this fission happened partially along lines of relatedness, relatedness did not structure the differences that we found. Taken together, this study suggests that distinct gut microbial profiles can emerge in social groups in less than one year and recommends further work into more finely mapping the timescales, causes, and potentially adaptive effects of this recurring trend toward distinct group microbial signatures.
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Discovery and full genome characterization of two highly divergent simian immunodeficiency viruses infecting Black-and-White Colobus monkeys (Colobus guereza) in Kibale National Park, Uganda
Retrovirology, 2013Co-Authors: Michael Lauck, William M. Switzer, Samuel D. Sibley, David Hyeroba, Alex Tumukunde, Geoffrey Weny, Bill Taylor, Anupama Shankar, Nelson Ting, Colin A. ChapmanAbstract:Background African non-human primates (NHPs) are natural hosts for simian immunodeficiency viruses (SIV), the zoonotic transmission of which led to the emergence of HIV-1 and HIV-2. However, our understanding of SIV diversity and evolution is limited by incomplete taxonomic and geographic sampling of NHPs, particularly in East Africa. In this study, we screened blood specimens from nine Black-and-White Colobus monkeys (Colobus guereza occidentalis) from Kibale National Park, Uganda, for novel SIVs using a combination of serology and “unbiased” deep-sequencing, a method that does not rely on genetic similarity to previously characterized viruses.
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Between-group variation in female dispersal, kin composition of groups, and proximity patterns in a Black-and-White Colobus monkey (Colobus vellerosus).
PloS one, 2012Co-Authors: Eva C. Wikberg, Pascale Sicotte, Fernando A. Campos, Nelson TingAbstract:A growing body of evidence shows within-population variation in natal dispersal, but the effects of such variation on social relationships and the kin composition of groups remain poorly understood. We investigate the link between dispersal, the kin composition of groups, and proximity patterns in a population of Black-and-White Colobus (Colobus vellerosus) that shows variation in female dispersal. From 2006 to 2011, we collected behavioral data, demographic data, and fecal samples of 77 males and 92 females residing in eight groups at Boabeng-Fiema, Ghana. A combination of demographic data and a genetic network analysis showed that although philopatry was female-biased, only about half of the females resided in their natal groups. Only one group contained female-female dyads with higher average relatedness than randomly drawn animals of both sexes from the same group. Despite between-group variation in female dispersal and kin composition, female-female dyads in most of the study groups had higher proximity scores than randomly drawn dyads from the same group. We conclude that groups fall along a continuum from female dispersed, not kin-based, and not bonded to female philopatric, kin-based, and bonded. We found only partial support for the predicted link between dispersal, kin composition, and social relationships. In contrast to most mammals where the kin composition of groups is a good predictor of the quality of female-female relationships, this study provides further support for the notion that kinship is not necessary for the development and maintenance of social bonds in some gregarious species.
Tara R. Harris - One of the best experts on this subject based on the ideXlab platform.
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Variation in diet and ranging of black and white Colobus monkeys in Kibale National Park, Uganda
Primates, 2007Co-Authors: Tara R. Harris, Colin A. ChapmanAbstract:Recently, considerable intraspecific variation in the diets and ranging behavior of colobine monkeys has been described, although in most cases this has involved documenting variation between, not within, sites. Some African colobines, such as guerezas ( Colobus guereza ), are relatively abundant in disturbed habitats that are very heterogeneous, raising the intriguing possibility that even groups with overlapping home ranges may exhibit large behavioral differences. If such differences occur, it will be important to understand what temporal and spatial scales adequately portray a species’ or population’s diet and ranging behavior. This study documents within-site variation in the diet and ranging behavior of guerezas in the habitat types in which they are described to be most successful—forest edge and regenerating forest. We collected data on eight groups of guerezas with overlapping home ranges for 3–5 months each in Kibale National Park, Uganda. The guerezas were highly folivorous, with leaves constituting 78.5–94.0% of the groups’ diets. The percentage of mature leaves and fruit in the diet varied widely among and within groups. We show that differences among groups in the intensity with which they fed on specific tree species were not just related to phenology, but also to differences in the forest compositions of groups’ core areas. Range size estimates varied more than fivefold among groups and the minimum distance from groups’ core areas to eucalyptus forest (which all groups regularly fed in) was a better predictor of range size than was group size. These results reveal considerable variation in the diet and ranging behavior among groups with overlapping ranges and have implications for comparative studies, investigations of within- and between-group feeding competition, and the potential for populations to adapt to anthropogenic or natural environmental change.
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Plant DNA sequences from feces: potential means for assessing diets of wild primates.
American journal of primatology, 2007Co-Authors: Brenda J. Bradley, Colin A. Chapman, Tara R. Harris, Mathias Stiller, Diane M. Doran-sheehy, Linda Vigilant, Hendrik N. PoinarAbstract:Analyses of plant DNA in feces provides a promising, yet largely unexplored, means of documenting the diets of elusive primates. Here we demonstrate the promise and pitfalls of this approach using DNA extracted from fecal samples of wild western gorillas (Gorilla gorilla) and black and white Colobus monkeys (Colobus guereza). From these DNA extracts we amplified, cloned, and sequenced small segments of chloroplast DNA (part of the rbcL gene) and plant nuclear DNA (ITS-2). The obtained sequences were compared to sequences generated from known plant samples and to those in GenBank to identify plant taxa in the feces. With further optimization, this method could provide a basic evaluation of minimum primate dietary diversity even when knowledge of local flora is limited. This approach may find application in studies characterizing the diets of poorly-known, unhabituated primate species or assaying consumer–resource relationships in an ecosystem. Am. J. Primatol. 69:699–705, 2007. © 2007 Wiley-Liss, Inc.
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Between-group contest competition for food in a highly folivorous population of black and white Colobus monkeys {Colobus guereza)
Behavioral Ecology and Sociobiology, 2006Co-Authors: Tara R. HarrisAbstract:In theory, between-group contest (BGC) competition for food can greatly influence female social relationships and reproductive success in primates, but few studies have investigated whether such effects occur and, if so, under what ecological conditions. There is evidence that adult male black and white Colobus monkeys (Colobus guereza, “guerezas”) defend the food their mates need against other groups, suggesting that BGC competition is important in this species. Using data on feeding, ranging, vegetation patterns, and intergroup encounters between six neighboring guereza groups, I provide evidence that the highly folivorous guerezas at Kanyawara, Kibale National Park, Uganda, engaged in BGC competition over unevenly dispersed, relatively high-quality feeding areas or “core areas”. Intergroup aggression was common, and groups’ home ranges overlapped. Groups were more likely to initiate high-level aggression if they encountered another group within or near their core area, and groups that initiated and won encounters often fed in the same areas in which losing groups had fed. Guerezas fed selectively on species with contagious (clumped) distributions and concentrated their feeding efforts in areas of the forest that contained the most food (core areas). Groups could be ranked in a linear dominance hierarchy, and group rank number was inversely related to the quantity and quality of food in groups’ core areas. This study not only provides good evidence that BGC competition occurs in primates but it also reinforces the idea that folivore food resources may be worth defending.
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Black and White Colobus Monkey (Colobus guereza) Roars as a Source of Both Honest and Exaggerated Information About Body Mass
Ethology, 2006Co-Authors: Tara R. Harris, W. T. Fitch, Louis Goldstein, Peter J. FashingAbstract:Formant dispersion, the average spacing, in Hz, between the resonant frequencies of a vocalization, has been predicted to provide honest information about signaler body size. Previous descriptions of black and white Colobus monkey (Colobus guereza, ‘‘guereza’’) roars, however, suggest a formant dispersion that is far lower than expected for an animal its size, and could effectively exaggerate its body size. Nonetheless, recent research on red deer shows that even when the formant positions of vocalizations effectively exaggerate body size, they may still provide honest cues within a species. We investigate whether the frequency bands observed in the spectrograms of guereza roars represent formants, and whether roar formant dispersion and/or individual formants provide honest information about body size (specifically, body mass) relative to conspecifics, although perhaps not relative to other species. We document coordinated vertical movements in the frequency bands of guereza roars and show that these bands move independently of fundamental frequency, indicating that they represent formants. We show, for captive adult male guerezas, that signaler body mass significantly predicts roar formant dispersion, even for randomly selected calls. Body mass also predicts formants 2 and 3, but the relationships are not as strong as with formant dispersion. Our roar formant dispersion calculations predict a vocal tract length of approx. 29 cm, but anatomically determined guereza vocal tract length is much smaller: approx. 7–8 cm. Videotaped roars revealed no laryngeal movement during roars, but rather inflation of the subhyoid air sac. We measured the volume of this air sac (approx. 10 cm 3 ) and speculate that it may function in roars to exaggerate body size, relative to other species.
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Mating behavior and endocrine profiles of wild black and white Colobus monkeys (Colobus guereza): toward an understanding of their life history and mating system
American journal of primatology, 2006Co-Authors: Tara R. Harris, Steven L. MonfortAbstract:Black and white Colobus monkeys (Colobus guereza, “guerezas”) show no external signs of estrus, and little is known about their mating behavior or reproductive endocrinology. To learn more about the life history characteristics and mating system of guerezas, we documented the mating behavior and ovarian hormone profiles of 10 cycling, lactating, and pregnant females in a wild population. We studied six groups of guerezas in Kibale National Park, Uganda, and collected ad libitum data on their mating behavior. We collected urine samples every 1.9±0.2 days from potentially fertile females and quantified conjugated urinary estrogen (E1S) and progesterone (PdG) metabolites using enzyme immunoassay (EIA). Females solicited 50.5% of copulations, and most copulations occurred during the interval starting 5 days before presumptive ovulation and ending 2–3 days later, with the highest copulatory levels occurring close to ovulation. We show that the median ovarian cycle length is 24 days, the median gestation length is ∼158 days, the length of lactational amenorrhea is at least 7–8 months, and the median interbirth interval for females with surviving infants is ∼22 months. We also document overlap between females' receptive periods in one-male, two- to three-female groups, which may mean that male transfer into such groups is potentially profitable. Am. J. Primatol. 68:383–396, 2006.© 2006 Wiley-Liss, Inc.
Cyril C Grueter - One of the best experts on this subject based on the ideXlab platform.
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Feeding competition inferred from patch depletion in a supergroup of Rwenzori Black-and-White Colobus monkeys (Colobus angolensis ruwenzorii) in Rwanda
Behaviour, 2020Co-Authors: Alexandra Miller, Grace Uwingeneye, Dieudonne Ndayishimiye, Debra S. Judge, Beth A. Kaplin, Cyril C GrueterAbstract:Abstract Competition for food is often a cost associated with living in a group, and can occur in an indirect (scramble) or direct (contest) form. We investigated feeding competition in a supergroup of Rwenzori Black-and-White Colobus monkeys (Colobus angolensis ruwenzorii) in Rwanda, with the aim of establishing whether freedom from scramble competition allows these monkeys to form supergroups. We used the patch depletion method, measuring intake rate coupled with movement rate, to assess if food patches become depleted over the occupancy period. Resource depletion was evident when the Colobus fed on young leaves, but not when feeding on mature leaves. Scramble competition was inferred from a negative correlation between group size and change in intake rate over patch occupancy. Between-group contest competition was inferred from displacement from patches. Although feeding competition exists for select resources, limited competition for mature leaves may enable Rwenzori Colobus to live in a supergroup of hundreds of individuals in this montane forest.
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Spatiotemporal association patterns in a supergroup of Rwenzori Black-and-White Colobus (Colobus angolensis ruwenzorii) are consistent with a multilevel society.
American journal of primatology, 2020Co-Authors: Alex Miller, Grace Uwingeneye, Dieudonne Ndayishimiye, Debra S. Judge, Beth A. Kaplin, Shahadat Uddin, Cyril C GrueterAbstract:Primates display broad diversity in their social organization. The social groups of a few primate species are organized in a multilevel fashion, with large groups composed of multiple, core one-male units (OMUs). A characteristic of multilevel societies is that the higher levels can include hundreds of individuals. The Rwenzori Black-and-White Colobus (Colobus angolensis ruwenzorii) in the montane forests of Rwanda form supergroups and have been suspected to exhibit multilevel social organization. Here we present the first data on the "anatomy" of a supergroup numbering 500+ individuals. We identified subgroups within the supergroup based on progression data, extracting the social network structure from the time-stamped spatiotemporal distribution of passing individuals identified to age-sex class, and selecting an optimal time window for each network using the two-step approach developed by Uddin, Choudhury, Farhad, and Rahman (2017). We detail the existence of core units-multi-male units (MMUs) with a mean of 1.7 adult males and 3.1 adult females, as well as OMUs, all-female units and bachelor units composed of adult and sub-adult males. More than two-thirds of units are MMUs. These grouping patterns conform to a multilevel society with predominantly multi-male core units, a social system that has recently also been described for a population of the same taxon in Uganda. Individual identification will be required to corroborate these interpretations.
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Diet and Use of Fallback Foods by Rwenzori Black-and-White Colobus (Colobus angolensis ruwenzorii) in Rwanda: Implications for Supergroup Formation
International Journal of Primatology, 2020Co-Authors: Alex Miller, Debra Judge, Grace Uwingeneye, Dieudonne Ndayishimiye, Cyril C GrueterAbstract:When preferred foods are scarce, one strategy employed by primates is to switch to an alternative food item of lower quality or preferability, i.e., a fallback food. In the montane rainforest of Nyungwe National Park in southwestern Rwanda, Rwenzori Black-and-White Colobus ( Colobus angolensis ruwenzorii ) (hereafter Rwenzori Colobus) form a supergroup comprising hundreds of individuals. Over 13 mo we investigated how this supergroup uses resources in periods of resource abundance vs. periods of resource scarcity. Based on 5603 feeding records we first identified preferred foods and then identified fallback foods as those food categories or species whose consumption increases when preferred foods, or preferred food categories, are less available. When the availability of 19 preferred food items was low, fruticose lichens ( Usnea sp.) contributed >50% of the monthly diet for the Rwenzori Colobus. Moreover, consumption of lichens was significantly negatively related to the availability of preferred foods. Fruticose lichens can therefore be considered a fallback food for Rwenzori Colobus that sustains the supergroup during periods of reduced food availability. This result, in combination with previous findings that mature foliage in Nyungwe is of high quality and does not elicit feeding competition, points to the importance of resources in facilitating supergroup formation. However, several other montane forests in Eastern Africa also harbor fruticose lichens and yet support only small groups of Angolan Colobus, suggesting that additional factors such as sufficient forest size and limited fragmentation and hunting pressure by humans are required for supergroups to form.