Marina Cords

Marina Cords
Columbia University | CU · Department of Ecology, Evolution and Environmental Biology

PhD

About

150
Publications
30,942
Reads
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Introduction
Marina Cords currently works at the Department of Ecology, Evolution and Environmental Biology, Columbia University. Her main research interests comprise behavioral ecology, social behavior and development. She leads a long-term project on forest dwelling monkeys in western Kenya.

Publications

Publications (150)
Article
Primates are known for forming agonistic coalitions, but most data come from species in which agonism occurs frequently and rank predicts fitness. We analyzed coalitions and interventions in wild blue monkeys ( Cercopithecus mitis ), in which both agonism and third‐party involvement are relatively rare, and in which rank does not predict fitness. D...
Article
Accurately assessing primate diets is important in studies of behavioral ecology and evolution. While previous research has compared sampling methods (scan, focal), we examined how sampling schedule influences accuracy of dietary measures. We define sampling schedule as the combined distribution (random vs. consecutive) and frequency of sampling da...
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Female mate choice may drive sexual selection, but discerning whether female behaviors reflect free expression of choice or responses to constraints can be difficult. We investigated the efficacy of female choice in wild blue monkeys using 10 years of behavior and paternity data (N = 178 male–female dyads). Although blue monkeys live modally in one...
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Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID-19. W...
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Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of...
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Postings on social media on Twitter (now X), BioAnthropology News (Facebook), and other venues, as well as recent publications in prominent journals, show that primatologists, ecologists, and other researchers are questioning the terms "Old World" and "New World" due to their colonial implications and history. The terms are offensive if they result...
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Simple Summary From the perspective of a field research team comprising members of the local community around a rain forest in western Kenya, we describe the relationship between local people and their local primates. The local community tends to have little knowledge about the natural history of the monkeys living nearby, and a negative attitude t...
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In wild animals, injuries often arise from intraspecific contests and, therefore, may reveal challenges and selection pressures related to social conflict. We evaluated whether known aggressive patterns predicted injury patterns in wild blue monkeys, in which most injuries of known cause resulted from conspecifics. After describing the injuries and...
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Many tropical animals inhabit mosaic landscapes including human‐modified habitat. In such landscapes, animals commonly adjust feeding behavior, and may incorporate non‐natural foods. These behavioral shifts can influence consumers' nutritional states, with implications for population persistence. However, few studies have addressed the nutritional...
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Significance Age-related changes in the capability to produce healthy young are common in humans and are increasingly well documented in nonhuman animals. However, differences among species in the nature of these age-related changes remain poorly understood. We compare patterns and consequences of age-related changes in female reproductive performa...
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While most mammals show birth hour peaks at times of the 24-hour cycle when they are less active, there are exceptions to this general pattern. Such exceptions have been little explored, but may clarify evolutionary reasons for the diel timing of births. We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis...
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Is it possible to slow the rate of ageing, or do biological constraints limit its plasticity? We test the ‘invariant rate of ageing’ hypothesis, which posits that the rate of ageing is relatively fixed within species, with a collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the hi...
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For many group-living animals, acquiring adult dominance rank is an important social transition. In species with maternal rank “inheritance,” juveniles appear to acquire their adult rank by receiving coalitionary support from kin and by altering patterns of aggressive behavior as they age. Previous studies of rank acquisition, however, have focused...
Article
Animals make dietary choices to achieve adequate nutrient intake; however, it is challenging to study such nutritional strategies in wild populations. We explored the nutritional strategy of a generalist social primate, the blue monkey (Cercopithecus mitis). We hypothesized that females balance intake of nutrients, specifically non-protein energy a...
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Significance Extensive care of offspring by mothers is a fundamental trait of all mammals, including humans, and the loss of a mother can be catastrophic for offspring. Here, we identify previously undocumented ways in which the death of a mother affects her offspring, using long-term, longitudinal data from seven primate species. First, females th...
Preprint
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Is it possible to slow the rate of aging, or do biological constraints limit its plasticity? We test this ‘invariant rate of aging’ hypothesis with an unprecedented collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the highly regular relationship between life expectancy and lifesp...
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The number of males per group varies substantially in group-living primates, both between and within species. In blue monkeys (Cercopithecus mitis), males may temporarily join groups during annual mating seasons when sexually receptive females are present. A likely determinant of the number of males per group is female group size (the number of adu...
Preprint
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Primate offspring often depend on their mothers well beyond the age of weaning, and offspring that experience maternal death in early life can suffer substantial reductions in fitness across the lifespan. Here we leverage data from eight wild primate populations (seven species) to examine two underappreciated pathways linking early maternal death a...
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Previous studies have shown that the number, noise level, and activity level of zoo visitors can negatively influence the behavior of captive animals. This study combined these three factors into a single visitor impact score and assessed whether visitor impact predicted the frequency or occurrence of displacement activities, affiliative behaviors,...
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Primates develop slowly relative to their body size, a pattern posited to result from ecological risk aversion. Little is known, however, about how energy balance contributes to allostatic load in juveniles. Using data collected over 8 consecutive months, we examined variation in energy balance (as measured by urinary C-peptide) and how energy bala...
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Classical sexual selection theory predicts that males should mate eagerly, yet blue monkey males often reject females’ sexual invitations. We evaluated how males’ responses to female solicitations related to female characteristics, number of males and conceptive females present, and the male’s recent copulations. Using 12 years of data from a wild...
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To investigate the selective agents that shape signals, we examined function (adaptive benefit to signaler) in the boom loud call by male blue monkeys. Using natural observation and playbacks in a wild population in Kenya, we characterized boom function from conspecifics' behavioral responses and also variation in call usage relating to context and...
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Maternal effects are widespread in living organisms though little is known about whether they shape individual affiliative social behavior in primates. Further, it remains a question whether maternal effects on affiliative behavior differ by offspring sex, as they do in other physiological systems, especially in species with high levels of adult se...
Article
Generalist primates eat many food types and shift their diet with changes in food availability. Variation in foods eaten may not, however, match variation in nutrient intake. We examined dietary variation in a generalist‐feeder, the blue monkey (Cercopithecus mitis ), to see how dietary food intake related to variation in available food and nutrien...
Article
Primates develop slowly relative to their body size, a pattern posited to result from ecological risk aversion. Little is known, however, about how energy balance contributes to allostatic load in juveniles. Using data collected over 8 consecutive months, we examined variation in energy balance (as measured by urinary C-peptide) and how energy bala...
Article
Hans Kummer (1930–2013), a Swiss zoologist, pioneered the study of primate behavior in wild and captive settings, emphasizing proximate mechanisms of social organization as a research theme and the critical role of experiments as a method. Trained in the intellectual domain of European ethologists, Kummer contributed to the study of primate behavio...
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If animals increase inclusive fitness by cooperating with relatives, nepotism should involve maternal and paternal kin equally, all else being equal. Evidence of a behavioral bias toward paternal half‐siblings in primates is both limited and mixed, with most positive reports from papionins. To expand knowledge of paternal kin recognition, particula...
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In group-living species, individuals often have preferred affiliative social partners, with whom ties or bonds can confer advantages that correspond with greater fitness. For example, in adult female baboons and juvenile horses, individuals with stronger or more social ties experience greater survival. We used detailed behavioral and life history r...
Article
Earth's rapidly changing climate creates a growing need to understand how demographic processes in natural populations are affected by climate variability, particularly among organisms threatened by extinction. Long-term, large-scale, and cross-taxon studies of vital rate variation in relation to climate variability can be particularly valuable bec...
Chapter
Thelma Rowell (1935–), a British zoologist, spent much of her career studying the social behavior of African monkeys, both wild and captive. Educated in England, she spent her professional life in Uganda, Kenya, and the United States. Throughout her career, Rowell challenged commonly held views of primate behavior, sometimes in provocative ways.
Chapter
The Kakamega Forest is a small equatorial rainforest in western Kenya whose flora and fauna include central African and Afromontane taxa. The forest is a mosaic of habitat types, dominated by near-natural secondary growth. It supports a high density of primates. Those studied in detail include blue, red-tail, and DeBrazza guenons, as well as guerez...
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Signals that occur in multiple contexts and evoke varied responses from receivers underscore the challenges of assessing a signal’s function (adaptive benefit to signaler) or relationships between receivers’ responses and their own fitness. Our study investigated the “pyow” loud call of male blue monkeys in a wild population in western Kenya. Using...
Article
The relationship between bats and primates, which may contribute to zoonotic disease transmission, is poorly documented. We provide the first behavioral accounts of predation on bats by Cercopithecus monkeys, both of which are known to harbor zoonotic disease. We witnessed 13 bat predation events over 6.5 years in two forests in Kenya and Tanzania....
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Intergroup contests determine access to resources and influence the evolution of group living in social species. Asymmetries in resource-holding potential and payoffs should influence the outcome and intensity of such contests. We evaluated predictors of contest outcome and intensity using data collected over 40 months from 6 groups of wild blue mo...
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We provide male and female census count data, age-specific survivorship, and female age-specific fertility estimates for populations of seven wild primates that have been continuously monitored for at least 29 years: sifaka (Propithecus verreauxi) in Madagascar; muriqui (Brachyteles hypoxanthus) in Brazil; capuchin (Cebus capucinus) in Costa Rica;...
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Agonistic behavior features prominently in hypotheses that explain how social variation relates to ecological factors and phylogenetic constraints. Dominance systems vary along axes of despotism, tolerance, and nepotism, and comparative studies examine cross-species patterns in these classifications. To contribute to such studies, we present a comp...
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In species that live in one-male groups, resident males monopolize access to a group of females and are assumed to have higher reproductive success than bachelors. We tested this assumption using genetic, demographic, and behavioral data from 8 groups of wild blue monkeys observed over 10 years to quantify reproduction by residents and bachelors an...
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When resource competition within primate social groups is effective, high-ranking individuals generally gain fitness benefits. Contrary to expectations, female Cercopithecus mitis form linear dominance hierarchies without evidence for rank-related variation in fitness-relevant measures, raising questions about the evolution of guenon social structu...
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Kakamega Forest is a small remnant of Guineo-Congolian rainforest in Kenya. Along with direct observation, we used an automatic camera to sample the nocturnal and crepuscular mammalian fauna within 1.5 km of the Kakamega Forest Station near Isecheno. We detected 11 indigenous species belonging to 10 genera, as well as domestic cats and dogs. We dir...
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Kin-biased cooperative and affiliative behavior is widespread in social mammals and is expected to increase fitness. However, despite evolutionary benefits of cooperating with relatives, demographic circumstances may influence the strength of kin bias. We studied the relationship between maternal kinship and affiliative behavior among 78 wild adult...
Chapter
Among mammals, associations of two or more species are likely to involve taxa that are also gregarious intraspecifically, such as primates and delphinids. Although these two groups generally differ in habitat, diet, and the stability of their social units, they share mixed-species association as a conspicuous aspect of their behavior. We compare th...
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In species that live in one-male/ multi-female groups, resident males have more access to females than do bachelor males and should have a within-group reproductive advantage. We used a genetic analysis of 13 microsatellite loci to assign paternity to 111 offspring born over 10 years in 8 groups of wild blue monkeys. Resident males sired a maximum...
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The moth Achaea catocaloides Guenee (Lepidoptera: Erebidae, formerly Noctuidae) experiences periodic population irruptions in tropical Africa. Large numbers of adult moths were observed in the Kakamega Forest, Western Kenya in March 2012. Estimated densities of adult moths flying in surveyed forest areas were 6.8 individuals per square metre. Roost...
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Gregarious animals face unavoidable conflicts of interest and thus therefore are likely to evolve behavioral mechanisms that allow them to manage conflict and thus maintain their social bonds. Multiple forms of conflict management characterize primates, but far less research has focused on dolphins, especially under natural conditions. Captive stud...
Article
In social mammals, within-group competition for food can drive variation in female fitness. Frugivores may face particularly strong competition because they use patchily distributed usurpable resources. Dominance rank and group size influence how a female experiences within-group competition. Both are predicted to affect access to food and, thus, r...
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Women rarely give birth after ∼45 y of age, and they experience the cessation of reproductive cycles, menopause, at ∼50 y of age after a fertility decline lasting almost two decades. Such reproductive senescence in mid-lifespan is an evolutionary puzzle of enduring interest because it should be inherently disadvantageous. Furthermore, comparative d...
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Animals facing seasonal variation in food availability experience selective pressures that favor behavioral adjustments such as migration, changes in activity, or shifts in diet. Eclectic omnivores such as many primates can process low-quality fallback food when preferred food is unavailable. Such dietary flexibility, however, may be insufficient t...
Data
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List of General Linear Mixed Models testing hypotheses about the causes of monthly fGCs variation. Models include reproductive state, feeding behavior, social interactions, and fiber content, for six non-consecutive months. Shown are multivariate models with non-zero fixed effects as well as univariate models for all predictors (controlling for rep...
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Effect of reproductive state on individual differences in fGC excretion. The figure shows fecal GC excretion in pregnant (grey bars) and non-lactating, non-pregnant females (white bars) during the four months preceding the peak of the birth season. The numbers above the x-axis indicate sample sizes. Females were included only if more than five feca...
Data
Full-text available
List of General Linear Mixed Models testing hypotheses about the causes of monthly fGCs variation. Models include reproductive state, estimates of food availability (FA), rainfall, and fiber content, for six non-consecutive months. Shown are multivariate models with non-zero fixed effects as well as univariate models for all predictors. Evidence ra...
Data
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Assessing the influence of confounding factors on sample fGCs. (PDF)
Data
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Temporal variation in mean fGC excretion in 21 female blue monkeys. Each line shows the temporal change in fGC concentrations, relative to the group mean, for one female. Relative changes over time during the study period are similar among females regardless of their reproductive states. (PDF)
Data
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List of General Linear Mixed Models testing hypotheses about the causes of monthly fGCs variation. Models include the best behavioral and environmental predictors identified in Tables S1 and S2. Evidence ratios give the odds against a given model being the best model, given the data and the best model in the set. (PDF)
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Examining seasonal mortality patterns can yield insights into the drivers of mortality and thus potential selection pressures acting on individuals in different environments. We compiled adult and juvenile mortality data from nine wild non-human primate taxa to investigate the role of seasonality in patterns of mortality and address the following q...
Article
Highlights ► Predation risk and social factors influence vigilance in wild blue monkeys. ► The primary function of vigilance in blue monkeys is most likely predator detection. ► The identities, but not number, of neighbours influenced vigilance duration. ► In a mildly aggressive species, social monitoring is a minor component of vigilance. ► Social...
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The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to hu...
Chapter
Long-term studies uniquely allow researchers to investigate phenomena that play out over long periods, as well as rare events that accumulate slowly into a respectable sample. This chapter takes both approaches in reporting on a 30-year study of blue monkeys (Cercopithecus mitis stuhlmanni), reviewing life-history data mainly for females, which can...
Article
As natural forest cover declines, planted forests have come to occupy an increasing percentage of the earth's surface, yet we know little about their suitability as alternative habitat for wildlife. Although some primate species use planted forests, few studies have compared primate populations in natural and nearby planted forests. From March 2006...
Article
The presence of unknown dyadic relationships is a common problem in constructing dominance hierarchies for groups of social animals. Although previously acknowledged, the influence of unknown relationships on hierarchy measures like linearity and steepness has not been studied in detail. Using real data-sets from four groups of wild monkeys, we ill...
Article
Socioecological theory predicts that aggressive feeding competition is associated with linear dominance hierarchies and reproductive advantages for high-ranking females. Female blue monkeys contest fruits and have a linear dominance hierarchy, yet previous research has shown no evidence that high-ranking females benefit from greater feeding success...
Article
Michael Cords, Ebara International Corporation, US, shares his views on the way to remove the distinction between single and two phase cryogenic liquid expanders. The aim of both types of liquid expanders is to increase the economic benefit of the process train, which is accomplished by increasing the efficiency of the process by means of increasin...
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Human senescence patterns-late onset of mortality increase, slow mortality acceleration, and exceptional longevity-are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence fa...
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In a stochastic environment, long-term fitness can be influenced by variation, covariation, and serial correlation in vital rates (survival and fertility). Yet no study of an animal population has parsed the contributions of these three aspects of variability to long-term fitness. We do so using a unique database that includes complete life-history...
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Infanticide by males is widespread across mammals and especially prevalent among primates. Considerable research has examined how fitness benefits can explain the occurrence of this behavior; less is known, however, about intrapopulation variation in its occurrence. We evaluated 10 infanticides by males in wild blue monkeys according to the sexual...
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Comparative data from wild populations are necessary to understand the evolution of primate life history strategies. We present demographic data from a 29-yr longitudinal study of 8 groups of individually recognized wild blue monkeys (Cercopithecus mitis stuhlmanni). We provide estimates of life history variables and a life table for females. Most...
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1. The importance of data archiving, data sharing and public access to data has received considerable attention. Awareness is growing among scientists that collaborative databases can facilitate these activities. 2. We provide a detailed description of the collaborative life history database developed by our Working Group at the National Evolutiona...
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13 females and 12 of 19 males present in a group of blue monkeys (Cercopithecus mitis stuhlmanni) mated promiscuously during an intense bout of sexual activity. Several aspects of their behavior are considered as mechanisms for determining mating patterns. Estrus synchrony coincided with a multi-male influx, allowing promiscuity. The length of stay...
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and Summary Redtail monkeys have been described as living in groups with a single “harem” ♂. Observations of a group of redtails including one breeding season suggest that the social structure of this species is variable both in time and space. An influx of 7 ♂ ♂ into the group over the course of 6 months coincided with estrus in all ♂♂ in the grou...
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Juveniles should choose social partners on the basis of both current and future utility. Where one sex is philopatric, one expects members of that sex to develop greater and sex-typical social integration with group-mates over the juvenile period. Where a partner's position in a dominance hierarchy is not associated with services it can provide, on...
Article
While habitat disturbance and food availability are major factors thought to determine the abundance of primates, evidence for their importance is uneven. We assessed the effects of these factors on three monkey species, guerezas (Colobus guereza), blue monkeys (Cercopithecus mitis) and redtails (Cercopithecus ascanius), in four areas of the Kakame...
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The adaptive function of cheek pouches in the primate subfamily Cercopithecinae remains unresolved. By analyzing the circumstances of cheek pouch use, we tested two hypotheses for the evolution of cercopithecine cheek pouches proposed in earlier studies: (1) cheek pouches reduce vulnerability to predation, and (2) cheek pouches increase feeding eff...
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While blue monkey groups often defend feeding territories against their neighbours, group members do not participate equally. Data spanning 5 years and 5 wild groups were used to address factors that might explain variable participation, both across age-sex classes and among individual adult females. Adult females participated most, although there...
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Primates in Perspective is the first edited volume to offer a comprehensive overview of primatology since 1987. Forty-four original essays--by fifty-nine leading researchers in the field today-- provide wide-ranging and contemporary coverage of all of the major areas of primatology. Arranged in six sections, the text begins with an introduction to...
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We evaluated four factors that may influence the process of male natal dispersal in wild female-philopatric blue monkeys: aggressive eviction by adults, attraction to oestrous females, social integration in the natal group and survivorship risk. Observations of nine males and five females of dispersal age allowed us to compare the social behaviour...