bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Patch Size on Feeding Associations in Muriquis (Brachyteles arachnoides)
Authors: Strier Karen B.
Published: September 2008

Data were collected on one group of muriquis, or woolly spider monkeys (Brachyteles arachnoides) during a 14-month study at Fazenda Monies Claros, Minas Gerais, Brazil to examine the effects of food patch size on muriqui feeding associations. Muriqui food patches were larger than expected from the availability of patch sizes in the forest; fruit patches were significantly larger than leaf patches. Feeding aggregate size, the maximum number of simultaneous occupants, and patch occupancy time were positively related to the size of fruit patches. However, a greater number of individuals fed at leaf sources than expected from the size of these patches. Adult females tended to feed alone in patches more often than males, whereas males tended to feed in single-sexed groups more often than females. Yet in neither case were these differences statistically significant.
Fish: A New Addition to the Diet of Japanese Macaques on Koshima Island
Authors: Watanabe Kunio
Published: September 2008

Recently, Japanese macaques on Koshima Island have begun to eat raw fish. This new habit was first observed in 1979, in adult males that live on the periphery of the group of macaques. The habit was first transmitted to the old dominant females in the group and then spread gradually to most other members of the group over the next 6 years. However, Koshima macaques do not appear to have a particular liking for fish. The eating of fish is discussed in relation to recent nutritional conditions in the macaques’ habitat.
A Large Pliopithecine Molar from Germany and Some Notes on the Pliopithecinae
Authors: Begun David R.
Published: September 2008

A lower molar of a large-bodied pliopithecine from the West German locality of Salmendingen is described and attributed to the taxon Anapithecus cf. hernyaki. This identification is used with other evidence to support the hypothesis that a femur from the nearby locality of Eppelsheim should be attributed to the Pliopithecinae. These newly identified pliopithecine fossils provide evidence of primate diversity and morphological uniqueness in the Late Miocene of Europe.
Mortality of Wild and Captive Chimpanzees
Authors: Courtenay Jackie , Santow Gigi
Published: September 2008

Mortality of chimpanzees in the wild (Gombe National Park) and in captivity (Taronga Zoo, Sydney and Melbourne Zoo) was compared using standard cohort life table techniques. Overall mortality probabilities up to age 30 were compared using a logrank test. No significant difference in overall mortality was revealed, and the mortality curves did appear to be surprisingly similar, but there were nevertheless some differences in the distribution of mortality. Perinatal mortality was higher in the zoo, while post-perinatal and infant mortality were higher in the wild. Survivorship in the older zoo animals (over age 27) was better than the wild. These differences were attributed to the more sheltered zoo environment, including the availability of veterinary care, which could be expected to improve survival in infants and older adults. The higher perinatal mortality experienced by zoo infants could be reflecting higher levels of inbreeding among the zoo animals.
Imaging Workstations for Computer-Aided Primatology: Promises and Pitfalls
Authors: Vannier Michael W. , Conroy Glenn C.
Published: September 2008

In this paper, the application of biomedical imaging workstations to primatology will be explained and evaluated. The technological basis, computer hardware and software aspects, and the various uses of several types of workstations will all be discussed. The types of workstations include: (1) Simple – these display-only workstations, which function as electronic light boxes, have applications as terminals to picture archiving and communication (PAC) systems. (2) Diagnostic reporting – image-processing workstations that include the ability to perform straightforward manipulations of gray scale and raw data values will be considered for operations such as histogram equalization (whether adaptive or global), gradient edge finders, contour generation, and region of interest, as well as other related functions. (3) Manipulation systems – three-dimensional modeling and computer graphics with application to radiation therapy treatment planning, and surgical planning and evaluation will be considered. A technology of prime importance in the function of these workstations lies in communications and networking. The hierarchical organization of an electronic computer network and workstation environment with the interrelationship of simple, diagnostic reporting, and manipulation workstations to a coaxial or fiber optic network will be analyzed.
Applications of the Reflex Instruments in Quantitative Morphology
Authors: MacLarnon Ann M.
Published: September 2008

The Reflex instruments are a set of non-contact measuring instruments enabling direct measurement in three dimensions of relatively small objects, or of stereophotographs. In addition to the range of geometric calculations which the standard software provided with the instruments can perform directly on the output of three-dimensional coordinates, the data can also be used to generate contour plots, three-dimensional computer representations, etc. The instruments have been used to measure hard tissues such as teeth, jaws and vertebrae, soft tissues such as gums, leg ulcers and Drosophila, and impressions such as footprints and bitemarks. Among the advantages of the instruments, in different studies their use has improved precision, speeded up measurement, avoided the need to take X-rays and avoided possible damage to objects.
Aspects of Line-Fitting in Bivariate Allometric Analyses
Authors: Martin Robert D. , Barbour Andrew D.
Published: September 2008

One of the fundamental problems involved in analyses of the scaling effects of body size (allometric analysis) is the choice of an appropriate best-fit line in bivariate logarithmic plots. Following a discussion of some basic aspects of allometric analysis, the two main procedures for the determination of a best-fit line – the least-squares regression and the major axis – are examined with respect to their different properties and underlying models. It is important to distinguish intraspecific from interspecific scaling and to recognize the distinction between use of a best-fit line to define a relationship and use of the line for prediction. An alternative model to the bivariate normal distribution, referred to as the ‘extruded normal distribution’, is presented and its implications are examined with respect to two test cases (scaling of basal metabolic rate in human males; scaling of population density in mammals).
Biomechanics and Allometric Scaling in Primate Locomotion and Morphology
Authors: Demes Brigitte , Günther Michael M.
Published: September 2008

Body size has a dominant influence on locomotor performance and the morphology of the locomotor apparatus. In locomotion under the influence of gravity, body mass acts as weight force and is a mechanical variable. Accordingly, the application of biomechanical principles and methods allows a functional understanding of scaling effects in locomotion. This is demonstrated here using leaping primates as an example. With increasing body size, the decreasing ratio of muscle force available for acceleration during takeoff to the body mass that has to be accelerated dictates both the movement pattern and the proportions of the hindlimbs. In an arm-swinging movement, the long, heavy arms of the large-bodied leapers are effectively used to gain additional momentum. A new perspective on decreasing size identifies the absolutely small acceleration distance and time available for propulsion as factors limiting leaping distance and extensively determining locomotor behavior and body proportions. As the mechanical constraints differ according to body size for a given mode of locomotion, a typological approach to morphology in relation to locomotor category is ruled out. Across locomotor categories, dynamic similarity (sensu Alexander) can be expected if the propulsive mechanisms as well as the selective pressures acting upon locomotion are the same.
Inferences from Quantitative Analysis of Dental Microwear
Authors: Walker Alan , Teaford Mark
Published: September 2008

Tooth microwear studies have been carried out for several reasons in the last decade. Most effort has been put into categorizing wear types that reflect dietary preferences in order to reconstruct the diet of extinct species. Several studies have shown that, for primates, carnivores and ruminants, it is possible to differentiate statistically the microwear associated with the major dietary adaptations in the group. It has further been found that more subtle dietary changes, such as seasonal ones, can be picked up if the sampling is good enough. It is important to recognize that, although it may be a valuable and legitimate concern to study the specific causes of different microwear patterns, that information is not essential for dietary reconstruction, if different microwear states can be shown empirically to correspond to different dietary regimes. Image enhancement and optical diffraction methods offer hope of automated scanning of large samples. This will be a major benefit as the methods currently in use are labor-intensive and time-consuming. Finally, it is urged that as many methods as possible be used to solve problems of dietary reconstruction.
Quantitative Aspects of the Estimation of Evolutionary Trees
Authors: Friday Adrian
Published: September 2008

Various approaches to the estimation of evolutionary trees are reviewed, with emphasis on recent developments. It is argued that no approach is ‘model-free’, that is, without some assumptions about the processes of evolutionary change. A statistical approach provides a general framework and it is accepted that cladistic methodology represents a special case within this framework. The idea of evolutionary convergence is examined in the light of recent discussion of the existence of convergence in molecular evolution. It is concluded that attempts to estimate evolutionary trees are justifiable at least on the grounds that, despite present shortcomings, they are the most appropriate way to analyse comparative data. There are good prospects for further progress.
Ecological Modelling in an Evolutionary Context
Authors: Dunbar R.I.M.
Published: September 2008

I argue that one of the strong features in disciplines like molecular biology and cosmology is the extent to which they use a powerful theoretical framework to generate and test quantitative predictions. Studies of biological evolution can exploit a similar advantage by integrating our current understanding of physiological and sociobiological processes to generate models of much greater sophistication than has commonly been the practice hitherto. I illustrate this with a number of examples drawn from the evolutionary biology of human and nonhuman primates.
Social Relations in Groups of the Black-Capped Capuchin (Cebus apella) in Captivity
Authors: Welker Christian , Becker Petra , Höhmann Hella , Schäfer-Witt Cornelia
Published: September 2008

During the second half-year of life, capuchin monkey infants maintain close contacts to kin-related animals. Apart from these contacts, they frequently interact with other infants and juveniles 1 year older. During this period of life the ‘peer phase’ begins in the life of the infants. Furthermore, gender differences, especially in respect to social play, become obvious.
Food-Sharing in Cotton-Top Tamarins (Saguinus oedipus)
Authors: Feistner Anna T.C. , Price Eluned C.
Published: September 2008

Food-sharing behaviour was observed in 9 captive families of cotton-top tamarins (range 4–14 individuals per group), during meals of fresh fruit. Food was transferred to infants by their parents and older sibs in response to begging, and was also offered to them without prior solicitation. Older, mature, reproductively suppressed individuals shared more than young immature monkeys. Infants in larger families received more food than those in smaller ones, though individuals in smaller families shared more. Transfer to infants increased to a maximum at 12 weeks of age and then declined gradually. At one year of age they no longer received food from others. Food sharing by older siblings is a form of helping behaviour which may increase their inclusive fitness, and benefit parents, both directly, by reducing the costs they incur in rearing young, and indirectly, by increasing the amount of food available to infants.
Medial Hypothalamic Lesions and Sexual Receptivity in the Female Common Marmoset (Callithrix jacchus)
Authors: Dixson A.F.
Published: September 2008

Medial hypothalamic lesions cause major deficits in sexual receptivity in a variety of mammalian species. Effects of such lesions upon sexual receptivity in female primates have not been investigated. Two experiments are described in which thermal lesions were made in the hypothalamus in 11 ovariectomized or ovariectomized/adrenalectomized, oestradiol-treated common marmosets. Proceptivity (sexual initiating behaviour) was reduced or abolished by lesions in the dorsomedial or ventromedial hypothalamus. Sexual receptivity was unaffected except in 3 females in which damage to the ventromedial area was associated with a 25–42% increase in terminations of males’ mounts. However, this effect was reversed by treating females with oestradiol. Therefore, medial hypothalamic lesions have pronounced effects upon proceptivity in the marmoset, whereas effects upon receptivity are much less pronounced or absent. These results are discussed in relation to the evolution of the hormonal control of receptivity in anthropoid primates as compared to other mammals.
Tool Use and Tool Making in Wild Chimpanzees
Authors: Boesch Christophe , Boesch Hedwige
Published: September 2008

Reported incidences of tool use and tool making for three wild chimpanzee populations increase from Mahale (12 and 3 types of use and making, respectively), Gombe (16 and 3) to Taï (19 and 6). Sticks are commonly used and prepared at all three sites. However, Taï chimpanzees seem to perform more modifications on the material before using it. They are also the only chimpanzees seen to pound objects with tools and to combine two different tool uses to get access to one food item. Tool making is the rule for abundant material (grass, twigs), but appears to be rarer for scarce, hard material (clubs, stones). Factors involved in the acquisition and the benefit of tool use are discussed along with factors affecting the frequency and complexity of tool making in chimpanzees.
Early Behavioral Development in Capuchins (Cebus)
Authors: Fragaszy Dorothy Munkenbeck
Published: September 2008

Capuchin infants (genus Cebus) are born in a behaviorally more altricial state than is known for infants of other primate taxa except apes. Development in the first 2 months after birth is characterized by the major reorganization of sleeping and waking, assumption of postural control and the appearance of prehension. Capuchins develop postural control, prehension and locomotion later than do squirrel monkeys, baboons or macaques, presenting a pattern of motor development intermediate between these relatively more precocial genera and apes. Capuchins provide a useful model primate system in which to study development and its links with behavioral variability and life history.
Tool Use in Cebus
Authors: Visalberghi Elisabetta
Published: September 2008

This paper summarizes early anecdotal information and systematic studies of tool use in capuchin monkeys (Cebus spp.)· Tool use in capuchins is neither context specific nor stereotyped. The success of capuchins in using tools and in exploiting a variety of food resources in the wild derives from several factors: their manipulative abilities, interest in external objects and a tendency to explore the environment. In using tools, capuchins are similar to apes and more proficient than other monkey species. A cognitive approach indicates, however, that (in contrast with chimpanzees) they never develop an understanding of the requirements of the tool tasks presented.
Significance of Kin Relations and Individual Preferences in the Social Behaviour of Cebus apella
Authors: Welker C. , Höhmann H. , Schäfer-Witt C.
Published: September 2008

Captive tufted capuchins (Cebus apella) formed a group characterized by greater affiliative behaviour within matrilines. Affiliation within the matriline is dependent upon social intimacy during infancy with matriline members. Courtship and mating are not identically distributed: subordinate and subadult males participate in a larger proportion of matings than of courtships. In all these aspects of social behaviour, variability across individuals contributes to the complex dynamics of the social group.
Dietary Variability in Cebus apella in Extreme Habitats: Evidence for Adaptability
Authors: Brown Alejandro D. , Zunino Gabriel E.
Published: September 2008

The dietary composition of Cebus apella in two subtropical forest environments of Argentina reflects the seasonal availability of potential food resources. In the marginal areas of the geographical distribution of this species, different resources are used during periods of scarcity. A greater tendency to use leaves in the diet is observed in the northwest (El Rey National Park), where there is greater seasonal variation of fruit availability. In El Rey, where there are few potential resources, the diet is dominated by a few resources, notably bromeliads. Where the resources are more abundant and the availability is more constant throughout the years (Baritú and Iguazú National Parks), the monkeys exhibit a feeding behavior similar to that seen in tropical areas. This ability of the genus Cebus to exploit resources not accessible to other primate species is one of the reasons for its wide geographical distribution and its widespread existence in ecosystems marginally used by primates.
Vertebrate Predation in Cebus capucinus: Meat Eating in a Neotropical Monkey
Authors: Fedigan Linda Marie
Published: September 2008

A long-term study of two groups of white-faced capuchins (Cebus capucinus) in Santa Rosa National Park in Costa Rica provides evidence of unusually high levels of vertebrate predation compared to those reported in other field studies of Cebus. The hunting techniques for different prey types are described, and several questions concerning vertebrate predation in primates are addressed. Why is there variation between individuals and between groups in the rate of predation? Why do males hunt more than females? Previous hypotheses to explain hunting in Old World primates are applied to this Neotropical example. Finally, I argue that successful vertebrate predation can readily arise in species like Cebus, which are characterized by opportunistic foraging patterns, manipulative and cognitive skills and well-developed techniques for locating and subduing invertebrate prey.
Cytogenetic Variability within and across Populations of Cebus apella in Argentina
Authors: Mudry M.D.
Published: September 2008

Two geographically separated populations of Cebus apella are found in Argentina. We have found important differences in the phenotypic characteristics of these populations, despite marked karyotypic similarity. Two well-distinguished phenotypes were established. Individuals from the northwest of Argentina are phenotypically similar to the Paraguayan populations and are recognized as C. apella paraguayanus. This subspecies is also found in the northeast of Argentina. Other specimens from the northeast are more similar phenotypically to the Brazilian subspecies C. apella nigritus and C apella libidinosus and are designated as C. apella vellerosus. The two subspecies C. apella paraguayanus and C. apella vellerosus share the same diploid number of chromosomes (2n = 54). Cytogenetic comparisons using G-, Q- and R-banding techniques and C-banding methods with the chromosomes carrying large heterochromatic blocks (No. 3, 5, 11, 12, 13, 19) showed differences between the subspecies. The presence of different polymorphisms and even of heteromorphisms in the same chromosomic pair across geographically isolated populations of the same subspecies is illustrated with Argentinian and Paraguayan specimens.
Ecological Constraints on Group Size in Three Species of Neotropical Primates
Authors: Chapman Colin A.
Published: September 2008

The foraging strategies and association patterns of 3 species of primates (Ateles geoffroyi, Alouatta palliata, Cebus capucinus) were studied over a 5-year period. The objective of the study was to provide a quantitative test of the hypothesis that the size, density and distribution of food resources influence the size of animal groups. In examining the assumptions of this hypothesis, it was shown that these primates used resources that occurred in patches, depleted the patches through their use, and that membership in large subgroups was associated with increased travel costs. The howler and spider monkey groups formed subgroups, the size of which could be predicted from the size, density and distribution of their plant food resources. When resources were clumped and at a low density, both the howler and spider monkeys were found in small subgroups, whereas when patches were uniformly distributed and at high density they formed larger subgroups. Capuchin monkeys, in contrast, did not respond to changes in these ecological variables by forming subgroups or changing the cohesion of their group.
Fragile Sons or Harassed Daughters?
Authors: van Schaik C.P. , de Visser J.A.G.M.
Published: September 2008

In most mammals, juvenile males tend to be more vulnerable to starvation than females and consequently experience a higher mortality. This has been attributed to selection on high male growth rates in response to strong intrasexual competition. Among primates, by contrast, it has been noted that females tend to be less viable as juveniles. This has been attributed to a greater ability of juvenile males to contest for food. An alternative explanation is that there is local resource competition, and adults of the resident sex (usually females) attempt to limit the recruitment of unrelated immatures of the same sex by harassing them. These ideas are not mutually exclusive. A set of predicitons from these three hypotheses was derived for two social systems and two levels of food supply. They were tested using estimates of juvenile mortality and juvenile sex ratios of non-human primates based on over 40 data sets drawn from the literature. The results indicate that the local resource competition hypothesis provides the best explanation for the observed patterns in differential juvenile mortality in primates. The contrast between the findings for primates and those for other taxa is attributed to the low growth rate of immatures and the widespread occurrence of conditions conducive to local resource competition in primates.
Peer Interaction in Infant Chimpanzees
Authors: Tomasello Michael , Gust Deborah A. , Evans Andrea
Published: September 2008

The peer interactions of 6 infant chimpanzees (Pan troglodytes) ranging in age from 18 to 50 months were observed in a seminatural context. The infants and their mothers lived as members of a captive social group at the Yerkes Regional Primate Research Center. An analysis of contact initiations between infants indicated that the most preferred peer interactant was the youngest and the least preferred was the oldest infant. Infants also initiated more interactions with the offspring of adults that had the closest relationships with both themselves and their mothers. These results indicate that a number of factors may influence the peer affiliations of infant chimpanzees, including the age of the infant and the mother’s social relationships.
Comparison of Auditory Functions in the Chimpanzee and Human
Authors: Kojima Shozo
Published: September 2008

Absolute thresholds for pure tones, loudness, frequency and intensity difference thresholds and the resonance of the external auditory meatus were measured in chimpanzees and compared with those in humans. Chimpanzees were more sensitive than humans to frequencies higher than 8 kHz but less sensitive to frequencies lower than 250 Hz and 2- to 4-kHz tones. Difference thresholds for frequency and intensity were greater in chimpanzees than in humans. The resonance of the external ear was about the same in the two species. The effects of differences in hearing between species upon speech perception are discussed.
Incisor Microwear and Diet in Three Species of Colobus
Authors: Kelley Jay
Published: September 2008

Examination of incisor microwear in three species of Colobus revealed that the predominantly folivorous C. badius more closely resembles C. satanas, a seed predator/ folivore, than C. guereza, another predominantly folivorous species. This demonstrates that species of the same broad dietary category can have very different patterns of incisor microwear, indicative of differences in food procurement behavior and/or the physical properties of dietary items for some portion of the diet. Conversely, species of different categories can have microwear patterns that, superficially at least, are quite similar. The dissimilarity in incisor microwear between C badius and C. guereza is mirrored to a certain extent in molar microwear, although the differences are not nearly so great on the molars. The differences between C. badius and C. guereza may involve different food items in the major, folivorous portions of their diets, or they may relate to differences in the very minor fruit and bark components. The similar microwear patterns of C. badius and C. satanas demonstrate that incisor microwear by itself is unreliable for assigning fossil species to broad dietary categories. Incisor microwear can be used to infer finer dietary distinctions in fossil species for which dietary category has been determined by other means.
A Comparative Study of Tolerance and Social Organization in Captive Lemurs
Authors: Blanckenhorn Wolf U.
Published: September 2008

The evolution of large, multimale primate groups from smaller family groups requires the evolution of higher levels of social tolerance. Relatively low tolerance towards conspecifics in social groups may be expressed in more dispersed spacing patterns, less frequent and intense grooming and higher agonistic interaction rates. I observed the social behavior of single troops of the closely related species Varecia variegata, which supposedly occur in small family groups, and Lemur fulvus and Lemur catta, which form multimale associations. The V. variegata group was significantly more dispersed than the other two groups. V. variegata also showed higher per capita levels of agonistic behavior and lower per capita levels of grooming behavior, as expressed in shorter and less frequent grooming bouts. This supports the few indications that wild V. variegata occur in smaller, perhaps family or extended family groups, as well as the prediction that species forming larger multimale associations like L. catta and L. fulvus have evolved higher degrees of social tolerance.
Birth Sex Ratio and Infant Mortality Rates in Captive Western Lowland Gorillas
Authors: Mace Georgina M.
Published: September 2008

A study of over 300 births to captive female gorillas revealed a significant trend for more male offspring to be born to older mothers and an especially marked tendency for very young mothers (less than about 8 years old) to give birth to a very low proportion of male offspring (31%). This finding is investigated with respect to the differing costs and benefits to the mother of rearing male and female offspring at different ages and stages of physical development. It is concluded that the observed pattern is likely to result from selective pressures on females to rear males at time when they can provision them most effectively, as male reproductive success probably varies more than that of females and may be dependent upon maternal care.
Grouping Patterns of a Mountain Population of Macaca sylvanus in Algeria – A Fission-Fusion System?
Authors: Ménard Nelly , Hecham Rachid , Vallet Dominique , Chikhi Hamid , Gautier-Hion Annie
Published: September 2008

Grouping patterns and population structure of Barbary macaques (Macaca sylvanus) living on rocky ridges in the Djurdjura Massif (Algeria) were studied from 1983 to 1988. The population consists of about 182 monkeys associated in variable ‘parties’ ranging in size from 7 to 58 individuals as a result of frequent migrations, fusions and fissions. The most frequently observed party size was 15–20 monkeys, and all but three parties were multimale-multifemale. Larger units, whose size and composition were more comparable to those of forest-living troops, were occasionally observed, suggesting a multilevel pattern of social organization. Our study population was characterized by a higher adult/immature ratio than that of forest-living troops, probably as a result of a higher rate of infant mortality. Furthermore, some evidence was found of a biased sex ratio in favour of males at birth. Possible proximate causes of these grouping patterns and population characteristics are discussed in relation to environmental and social constraints.
Geographical Variation in the Fork-Marked Lemur, Phaner furcifer (Primates, Cheirogaleidae)
Authors: Groves Colin P. , Tattersall Ian
Published: September 2008

The fork-marked lemur, Phaner furcifer, is discontinuously distributed through Madagascar, but is traditionally viewed as a monotypic species. Reexamination of variations in pelage color and pattern, size and body proportions among museum specimens reveals that several geographically discrete morphs exist within the species, which is clearly polytypic. We identify and name 2 new subspecies in western Madagascar, and 1 in the north of the island. The nominate subspecies is thought to be derived from the northeastern region, and it is possible that more discrete variants are present in that region than are formally recognizable on the basis of the current inadequate documentation. The limited nature of color variation in nocturnal lemurs relative to diurnal forms may have resulted in a general tendency to underestimate subspecific diversity in the former.
Similarities in Aegyptopithecus and Afropithecus Facial Morphology
Authors: Leakey M.G. , Leakey R.E. , Richtsmeier J.T. , Simons E.L. , Walker A.C.
Published: September 2008

Recently discovered cranial fossils from the Oligocene deposits of the Fayum depression in Egypt provide many details of the facial morphology of Aegyptopithecus zeuxis. Similar features are found in the Miocene hominoid Afropithecus turkanensis. Their presence is the first good evidence of a strong phenetic link between the Oligocene and Miocene hominoids of Africa. A comparison of trait lists emphasizes the similarities of the two fossil species, and leads us to conclude that the two fossil genera share many primitive facial features. In addition, we studied facial mophology using finite-element scaling analysis and found that the two genera show similarities in mophological integration, or the way in which biological landmarks relate to one another in three dimensions to define the form of the organism. Size differences between the two genera are much greater than the relatively minor shape differences. Analysis of variability in landmark location among the four Aegyptopithecus specimens indicates that variability within the sample is not different from that found within two samples of modern macaques. We propose that the shape differences found among the four Aegyptopithecus specimens simply reflect individual variation in facial characteristics, and that the similarities in facial moφhology between Aegyptopithecus and Afropithecus probably represent a complex of primitive facial features retained over millions of years.
A Study of Facial Growth in the Sooty Mangabey Cercocebus atys
Authors: O’Higgins P. , Bromage T.G. , Johnson D.R. , Moore W.J. , McPhie P.
Published: September 2008

This study examines the pattern of facial bone growth remodelling in the sooty mangabey (Cercocebus atys) by scanning electron microscopy (SEM) of high-accuracy replicas. The efficacy of the technique is appraised by SEM interpretations of facial remodelling in the crab-eating macaque (Macaca fascicularis) and correlative histological examination. The results indicate that the distribution of depository and resorptive areas in Cercocebus closely parallels that which has been observed in Macaca. It is suggested that the different adult facial morphologies in the sooty mangabey and crab-eating macaque are the result of changes in the rates of remodelling events that may be coupled with different patterns of sutural growth (which could not be studied by SEM).
Respiratory Muscle Activity during Vocalization in the Squirrel Monkey
Authors: Jürgens U. , Schriever S.
Published: September 2008

Inorder to find out which muscles are involved in the respiratory component of primate phonation, the activity of 17 abdominal and thoracic muscles was recorded during vocalization in the squirrel monkey. Vocalization-correlated activity was found in the musculi obliquus externus et internus, rectus et transversus abdominis, intercostalis externus et internus and intercartilagineus. It was lacking in the mm. iliocostalis, latissimus dorsi, longissimus dorsi, rhomboideus, serratus posterior superior, trapezius, splenius capitis, sternocleidomastoideus, scalenus medius and pectoralis major. There was simultaneous activation of the rib-raising external and rib-lowering internal intercostal muscles during most vocalizations. It is hence concluded that the intercostals, rather than supporting expiratory efforts, serve to stabilize the thorax, thus providing an anchorage against which the abdominal muscles can act.
Comparative Analyses of Age- and Sex-Specific Patterns of Vocal Behaviour in Four Species of Old World Monkeys
Authors: Hohmann G.
Published: September 2008

Sound recordings and behavioural data were collected from four primate species of two genera (Macaca, Presbytis). Comparative analyses of structural and behavioural aspects of vocal communication revealed a high degree of intrageneric similarity but striking intergeneric differences. In the two macaque species (Macaca silenus, Macaca radiata), males and females shared the major part of the repertoire. In contrast, in the two langurs (Presbytis johnii, Presbytis entellus), many calls were exclusive to adult males. Striking differences between both species groups occurred with respect to age-specific patterns of vocal behaviour. The diversity of vocal behaviour was assessed from the number of different calls used and the proportion of each call in relation to total vocal output for a given age/sex class. In Macaca, diversity decreases with the age of the vocalizer, whereas in Presbytis the age of the vocalizer and the diversity of vocal behaviour are positively correlated. A comparison of the data of the two genera does not suggest any causal relationship between group composition (e.g. multi-male vs. one-male group) and communication system. Within each genus, interspecific differences in vocal behaviour can be explained by differences in social behaviour (e.g. group cohesion, intergroup relation, mating behaviour) and functional disparities. Possible factors responsible for the pronounced intergeneric differences in vocal behaviour between Macaca and Presbytis are discussed.
Synergistic Effects of Kinship, Sex and Rank in the Behavioural Interactions of Captive Stump-Tailed Macaques
Authors: Santillán-Doherly A.M. , Diaz J.L. , Mondragón-Ceballos R.
Published: September 2008

In almost all non-human primate species kinship, sex and rank bias the patterning of interactions among subjects, seemingly in a way that favours the individual’s fitness. A number of studies have been done in order to study separately the effects of these variables, concluding that an adequate model of interactions cannot be developed assuming preponderance of a single variable. The ‘willingness’ of one animal to interact with another can be explained as the result of assessing the possible outcomes (proximate and/or ultimate) of the interaction. The interrelationship of variables such as kinship, sex and rank, among others, provides the actors with a basis for deciding their rates of social interactions. The following study was done to assess whether kinship, rank and sex exerted independent, additive effects in the within-group distributions of eight social behaviour categories of captive groups of stump-tailed macaques. We found that the three variables synergistically affected the patterning of all behavioural categories. This suggests that the pay-offs of social interactions do not vary linearly, being intrinsically correlated with the actors’ attributes so that uncertainty in the choice of a potential partner is minimized.
Natural Foods and Their Ecological Implications for Macaca thibetana at Mount Emei, China
Authors: Zhao Qikun , Deng Ziyun , Xu Jiemei
Published: September 2008

Natural food plants of partly provisioned groups of Macaca thibetana included about 196 species belonging to 135 genera and 72 families. The macaques consumed mainly bamboo shoots and fruits for about 2 months in autumn, whereas they relied on active or passive provisions from visitors, a variety of structural parts of plants and a small amount of invertebrates in late spring and summer and ate mainly mature leaves and bark for the rest of the year. About half of the species eaten came from the dense herb and shrub layers. This forest-dwelling species shows a distinctive feeding and foraging pattern in comparison with other macaques, explaining why M. thibetana has the largest body weight of all macaques.
Field Methods for Capture and Measurement of Three Monkey Species in Costa Rica
Authors: Glander Kenneth E. , Fedigan Linda Marie , Fedigan Laurence , Chapman Colin
Published: September 2008

A total of 54 free-ranging monkeys were captured and marked in Santa Rosa National Park, Costa Rica, during May 1985, and an additional 17 were captured during March 1986. The animals were darted using a blowpipe or a CO2 gun. The drugs used were Ketaset®, Sernylan® and Telazol®. Ketaset was effective for Cebus capucinus but unsuccessful for Alouatta palliata and Ateles geoffroyi. Sernylan was successful for A. geoffroyi and A. palliata but is no longer commercially available. Telazol proved to be an excellent alternative capture drug for both A. palliata and A. geoffroyi.
Functional Significance of Social Grooming in Primates
Authors: Dunbar R.I.M.
Published: September 2008

Frequencies of social grooming recorded from 44 species of free-living primates correlate with group size but not body size. This is interpreted as evidence for the social function of grooming and against the purely hygienic function. However, there is some evidence to suggest that body size is a more important determinant of grooming time among platyrrhine primates. This might imply that there has been a shift in the functional system governing grooming during primate evolution.
Patterns of Sexual Dimorphism in Body Weight among Prosimian Primates
Authors: Kappeler Peter M.
Published: September 2008

Many primatologists believe that there is no sexual dimorphism in body size in prosimian primates. Because this belief is based upon data that came from only a few species and were largely flawed in some aspect of sample quality, I re-examined the extent of sexual dimorphism in body weight, using weights of 791 adult prosimians from 34 taxa recorded over the last 17 years at the Duke University Primate Center. There was no significant sex difference in body weight in 17 species, but males were significantly larger in Nycticebus pygmaeus, Tarsius syrichta, Galago moholi, Galagoides demidovii, Otolemur crassicaudatus and Otolemur garnettii. Moreover, females were significantly larger in Microcebus murinus. Thus, the general lack of sexual dimorphism could be confirmed, notably for lemurs, but prosimians as a group show more variability in sexual size dimorphism than was previously thought. After including previously published data obtained in the wild from 8 additional species, I found significant heterogeneity in the degree of sexual dimorphism at the family level, but only the Indridae and Galagidae were significantly different from each other. Among the prosimian infraorders, the Lorisiformes were significantly more dimorphic than the Lemuriformes. Differences in dimorphism between higher taxonomic groups are discussed in the context of prosimian evolution, concluding that phylogenetic inertia cannot provide a causal explanation for the evolution of sexual dimorphism. The relative monomorphism of most prosimians may be related to allometric constraints and, especially in the Lemuriformes, to selective forces affecting male and female behavioral strategies.
Multivariate Comparison of the Forelimb between Stump-Tailed and Rhesus Macaques
Authors: Ruliang Pan , Yanzhang Peng , Zhizhang Ye
Published: September 2008

Rhesus macaques and stump-tailed macaques are sympatric in western Yunnan (China), coexisting or occupying habitats that show little difference. This paper tests hypotheses based on theoretical expectation from the differing biomechanical demands of terrestrial and arboreal quadrupedalism in stump-tailed macaques and rhesus macaques, respectively. Individuals of these two macaque taxa were markedly separated by the first two principal components and discriminant analyses based on 18 variables of the upper limb. The rhesus macaques appear to be more adapted for arboreal quadruped habits because of elongation of the clavicle and forearm, a larger humeral head and greater midshaft sagittal diameters of the radius and ulna.
Relationship between the Diet of Macaca fascicularis and Forest Phenology
Authors: Lucas Peter W. , Corlett Richard T.
Published: September 2008

The diet of a partly provisioned troop of long-tailed macaques (Macaca fascicularis) and the phenology of a 71-ha tropical rain forest reserve were studied over a 68-week period. Outside of a short period of flowering, followed 13 weeks later by a fruiting burst of similar duration, plant reproduction was limited. For both the total numbers of forest fruit species eaten and scan frequencies of feeding on fruit, there was a highly significant correlation with estimates of fruiting activity in the forest. Similar estimates for flowers were much more weakly associated. When fruit consumption peaked, insect foraging declined as did the acceptance of provisioned food. Most of the fruit species eaten were of an ‘unprotected’ fleshy type that is generally consumed by birds and bats. Dry fruits were underrepresented in the diet. The results suggest a preference for fleshy fruit and strong environmental control of the diet.
Dramatic Consequences of Food Handouts to Macaca thibetana at Mount Emei, China
Authors: Zhao Qi-Kun , Deng Zi-Yun
Published: September 2008

Food handouts to Macaca thibetαnα at Mt. Emei have had dramatic consequences for both man and monkey as tourism has increased over the last decade. Food handouts and human submissive behaviour facilitate beg-robbing by the monkeys, which can be regarded as a mixed conditioning chain. Because of their lack of understanding of primate behaviour and resulting inappropriate responses, many visitors have lost possessions and have been severely frightened or even injured; in fact there have been 10 deaths as an indirect result over that past 8 years. The appropriate human response proved to be the display of dominance to maintain a distance from a beg-robbing monkey. Road-ranging macaques have also been injured or killed by visitors to obtain meat or bones or merely for amusement. Attempts should be made to eliminate the negative effects of food handouts by increasing visitors’ awareness of behavioural and ecological aspects and through aversive conditioning of the macaques.
Oldest Known Nannopithex (Primates, Omomyiformes) from the Early Eocene of France
Authors: Godinot Marc , Russell Donald E. , Louis Pierre
Published: September 2008

Numerous dental remains of Nannopithex zuccolae, n. sp., from the terminal early Eocene locality of Prémontré (Aisne), France, show the lower anterior dentition to be similar to that of other Nannopithex. Similarities include enlarged I1, reduced I2, reduced lower canine, loss of P2, small P3 and large P4. Upper molars, P3 and P4 all present primitive characters, making this species the most primitive as well as the oldest known microchoerid.
Alloparental Care in Free-Ranging Lemur catta at Berenty Reserve, Madagascar
Authors: Gould Gould
Published: September 2008

Alloparental care was examined in three free-ranging groups of Lemur catta. Group members of all age/sex classes were found to participate to varying degrees in alloparental care of infants, and some types of care were performed significantly more frequently by animals of particular age/sex classes. Adult males, previously reported not to interact with infants, were found to groom and play with them occasionally. Rank or sex of the infant did not affect the amount of alloparental care it received. It is suggested that individuals of all age/sex classes can benefit from receiving or performing alloparental care. Infants can develop social skills and receive protection from alloparents; mothers gain free time to forage and rest; prereproductive females can learn parental skills; all adult females and prereproductive animals are aiding kin by alloparental care, and adult males, by interacting with infants, may have the opportunity to establish a relationship with the mother which could enhance future reproductive success.
Variations in Dental Measurements between Saguinus Species and Their Systematic Relationships
Authors: Natori Masahito , Hanihara Tsunehiko
Published: September 2008

Multivariate analysis is applied to dental measurements of Saguinus species to analyse their systematic relationships. The shape distance between Saguinus midas midas and S. midas niger is larger than that between S. nigricollis and S. fuscicollis, both of which are generally recognized as valid species. In dental form, S. bicolor is the closest relative of S. midas. S. inustus is not linked to S. leucopus, S. geoffroyi and S. leucopus, as S. inustus shows closer affinity with S. labiatus and S. mystax than with the former 3 species.
Underbite and the Scaling of Facial Dimensions in Colobine Monkeys
Authors: Emel Lynda Marie , Swindler Daris R.
Published: September 2008

This investigation was concerned with the dimensions of the facial skeleton and the incidence of underbite in colobine monkeys. Standard craniofacial dimensions and the notation of the presence or absence of underbite were recorded for skulls of 308 adult, wild-caught colobines belonging to 10 species. Underbite was noted in all species examined, ranging in frequency from 10% in Colobus polykomos to 100% in 2 species of Presbytis. Univariate statistics indicate that species with high frequencies of underbite tend to have shorter, broader maxillary dental arches, shorter faces and rostrums, and longer mandibular dental arches. A multivariate discriminant analysis supported the univariate statistics. Interspecific allometric analysis of facial measurements against a constructed size variable indicated that maxillary dimensions scale in a strongly positive manner in relation to size. However, mandibular dimensions tend to scale isometrically. This pattern of facial scaling indicates that the tendency toward underbite should increase as overall size decreases. This would explain why smaller species have higher frequencies of underbite than larger species and why females often have a higher incidence of underbite than conspecific males. Zingeser [5] has suggested that the high incidence of underbite in colobine and some cebid monkeys is an adaptation to folivory. The results of this study support an alternative hypothesis that the high incidence of underbite in colobine monkeys is related to the pattern of facial scaling with size in combination with relaxed selection on the anterior dentition.