European Federation of Primatology Meeting 2000

hosted by the Primate Society of Great Britain

A scientific meeting will be held in London on the 27^th, 28^th and 29^th November, 2000.

On Monday, 27th November there will be a series of workshops, lead by experts in different fields of primatology (to be held at University of Surrey Roehampton and at Goldsmiths College, University of London). These will explore a range of topical and methodological issues in primatology (see details below). Applications are invited, particularly from post-graduate students, although established researchers and undergraduates will also be welcome. The workshops are available as half day units and each participant will have the opportunity to attend two workshops. For further details about these workshops contact Ann MacLarnon (School of Life Sciences, University of Surrey Roehampton, West Hill, London SW15 3SN, U.K. Tel: +44 (0) 20 8392 3524, Fax: +44 (0) 20 8392 3527, E-mail: Life_Sciences@roehampton.ac.uk).

There will also be a poster display and wine reception at 6 pm on 27^th November at the University of Surrey Roehampton open to all meeting participants. Abstracts (maximum 200 words) should be submitted to Ann MacLarnon at a.maclarnon@roehampton.ac.uk, or School of Life Sciences, University of Surrey Roehampton, West Hill, London SW15 3SN by 31^st August 2000. Acceptance of posters will be notified in September. Posters should measure a maximum of 100cm (width) by 140cm (height).

During the following two days (28th and 29th November) the invited speakers programme (see below) will be held at the Meeting Rooms of the Zoological Society of London in Regent's Park, London. Further details about this part of the meeting may be obtained from Hilary Box (Department of Psychology, University of Reading, Whitenights, Reading, RG6 2AL, U.K. Tel.: +44 (0)118 9316668, Fax: +44 (0)118 9316715, E-mail: h.box@reading.ac.uk).

The local organising committee for the conference is Hilary Box (UK), Ann MacLarnon (UK), Hannah Buchanan-Smith (UK), Bertrand Deputte (France), together with the assistance of both the President of the Primate Society of Great Britain, Phyllis Lee and of the EFP, Régine Vercauteren Drubbel (Belgium). Members of the advisory committee also include Fernando Colmenares (Spain) and Augusto Vitale (Italy).

Registration for both the workshops and the conference is required. The deadline is 31^st August, 2000. Registration forms, which include details of registration fees, are enclosed in this issue of Primate Eye. Workshop Programme

27^th November

Goldsmiths College

1. Genetics & Evolution - Jan de Ruiter & Nick Mundy

   The combination of modern molecular genetics and new analytical methods herald an exciting time for primatology, from the level of intragroup relationships up to macroevolutionary patterns. In this workshop we will concentrate on some recent innovations in this field. Areas for discussion will include relatedness, population genetics and adaptive molecular evolution. As well as welcoming those with a general interest in the field, the workshop will provide an opportunity for people with their own datasets to bring them along.

2. Simian Viruses - David Brown & Myra McClure

   Through lecture and discussion, this workshop will look at the following questions: Which retroviruses affect primates? What are the effects of these infections? How can we test for retrovirus infections? How can we best deal with the infections?

3. Use of Primates in Research - Bertrand Deputte & Mark Matfield

   This workshop will consider the use of non-human primates in both fundamental and applied science, with particular emphasis on the ethical and welfare aspects. It will consist of short lectures from invited speakers, leading into a general workshop discussion of the issues raised.

University of Surrey Roehampton

1. Cognition & Social Complexity - Filippo Aureli & Robin Dunbar

   This workshop will cover theoretical, empirical and methodological issues in primate cognition and social complexity. Lecture and discussion sessions will deal with explanations of why primates have large brains, the complexity of primate social interactions, and the cognitive abilities associated with the regulation of social relationships.

2. Ecology & Sociality - Phyllis Lee & Volker Sommer

   This workshop will cover a range of topics such as female kin-bonding, mechanisms of competition, the role of males and mating systems in structuring social systems and predation. It will also consider the methodological problems of quantifying diet and food patches, activity budgets and time constraints, and grooming and social contests. Short (10 mins maximum) presentations by participants are welcome.

3. Behavioural & Physiological Development - Debbie Curtis, Ann MacLarnon, Chris Pryce & Jo Setchell

   This workshop is for people interested in both field and captive applications of behavioural and physiological techniques for studying ontogeny - from conception through gestation and postnatal development. Approaches to be considered include salivary, blood, urine and faecal assays, telemetry, behavioural observation and the comparative method. Participants will be able to discuss the suitability and limitations of different techniques in field and captive settings.

Invited Speakers' Programme

28^th November

9.55 Introductory remarks - Hilary Box

10.00 New Light on the Dates of Primate Origins and Divergence. Robert D. Martin (Universität Zürich-Irchel, Switzerland), Christophe Soligo (Universität Zürich-Irchel and The Natural History Museum, UK), Simon Tavaré (University of Southern California, USA), Oliver Will (University of Southern California, USA) and Charles Marshall (Harvard University, USA).

10.30 The Evolution of the Social Brain. Robin Dunbar (University of Liverpool, UK).

11.00 - 11.30 COFFEE

11.30 OSMAN HILL MEMORIAL LECTURE

Primate Comparative Anatomy and the Evolution of Reproduction. Alan Dixson (Zoological Society of San Diego, USA).

12.30 - 2.00 LUNCH

2.00 The Primate-Mother Relationship: Causes and Consequences. Christopher Pryce (Swiss Federal Institute of Technology, Zürich, Switzerland).

2.30 Field Endocrinology: Studying Hormone-Behaviour Interactions of Primates in the Wild. Keith Hodges (Deutsches Primatenzentrum, Göttingen, Germany).

3.00 - 3.30 TEA

3.30 Social and Genetic Structure of Polgynous Lemurs. Peter Kappeler (Deutsches Primatenzentrum, Göttingen, Germany).

4.00 Deconstructing Monogamy: Thailand's Gibbons at Khao Yai. Volker Sommer (University College, UK) and Ulrich Reichard (Max-Plank Institut für Evolutionäre Anthropologie, Leipzig, Germany).

4.30 - 6.00 SOCIAL GATHERING

29^th November

10.00 Managing Conflict in Group Living Primates. Filippo Aureli (John Moores University, Liverpool, UK).

10.30 Learning what to Eat: The Role of Social Influences in Capuchins. Elisabetta Visalberghi (CRN, Roma, Italy).

11.00 - 11.30 COFFEE

11.30 Two of a Kind: Alternative Sexual Strategies of Adult Male Orangutans. Jan van Hooff (Universiteit Utrecht, The Netherlands) and Susie Utami Atmoko (Universitas Nasional, Jakarta, Indonesia).

12.00 - 12.30 The Colobus of Tai forest: Three ways of Making a Living. Ronald Noë (Université Louis Pasteur, Strasbourg, France).

12.30 - 2.00 LUNCH

2.00 Conservation and SIV. Annie Gautier-Hion (CNRS Université de Rennes, France).

2.30 Primates, People and Development: The Conservation Challenges in Gabon. Caroline Tutin (Centre Internationale de Recherches Medicales de Franceville, Gabon, West Africa).

3.00 Molecular Ecology of Primates and the Impact of Non-Invasive Techniques. Mike Bruford (Cardiff University, Wales, UK).

3.30 GENERAL DISCUSSION

ABSTRACTS

EFP 2000 - designated and financially assisted by the EC as a High-Level Scientific Conference, and hosted by the Primate Society of Great Britain
28th and 29th November, 2000

New Light on the Dates of Primate Origins and Divergence

Robert Martin1, Christophe Soligo1, 2, Simon Tavare3, Oliver Will3 & Charles Marshall4
1 Anthropological Institute & Museum, University of Zürich, Switzerland
1, 2 Human Origins Programme, The Natural History Museum, London
3 Department of Mathematics, University of Southern California, USA
4 Department of Earth & Planetary Sciences, Harvard University, USA

Living primates excluding tree-shrews form a monophyletic unit containing 6 “natural groups” (lemurs, lorises, tarsiers, New World monkeys, Old World monkeys, apes and humans), whose early separation is confirmed by chromosomal and molecular comparisons. Continental drift may have influenced this subdivision if divergence times were relatively early. The earliest known unequivocal fossil primates are of basal Eocene age (about 55 Mya) and the standard view is that primates originated about 65 Mya. A similar conclusion has been reached for most orders of placental mammals, and it is widely accepted that the origin and radiation of most mammalian groups followed the extinction of dinosaurs at the end of the Cretaceous. A parallel explanation has been given for the adaptive radiation of modern birds. This all rests on the common procedure of dating the origin of a group by the first known fossil representative, perhaps adding a few million years. Such direct dating from the fossil record faces 2 problems: (1) If the fossil record is very fragmentary, the first known fossil representative is likely to be considerably more recent than the actual origin. (2) Bias in the fossil record may introduce further error. This has direct implications for the common practice of calibrating molecular trees with a single date for the first known fossil of a group. (Here, it is important to distinguish between the time at which a group diverged and the time at which its diversification began.) A simple calculation by Martin (1993) indicated that only 3% of extinct primate species have so far been documented. Poor sampling is also indicated by a still-accelerating discovery rate for new fossil species. Rough correction for underestimation of the time of origin led to the proposal that ancestral primates existed about 80 Mya. This has now been confirmed by our newly developed statistical approach. By contrast, Gingerich & Uhen (1994) calculated that the probability of primates originating 80 Mya was below 5 in a billion. This calculation is demonstrably spurious. Major gaps in the primate fossil record undoubtedly exist, as is true of the mammalian fossil record generally. In the most dramatic primate example, documentation of Malagasy lemurs is limited to subfossils just a few thousand years old, yet it is known that they must have existed at the very least for 20 MY, as the sister-group (lorisiforms) is documented by fossils of that age. Poor documentation of early placental mammals by the fossil record is strikingly illustrated by 2 cases: (1) bats, (2) anteaters. Several recent results from analyses of molecular data using a range of calibration dates external to primates have confirmed an early date for the origin of primates. Inference of divergence times for bird and mammal orders from nuclear gene divergence, calibrated with the well-documented split between synapsid and diapsid reptiles, set the origin of primates at about 90 Mya (Hedges et al, 1996; Kumar et al, 1998). Demonstration of an African clade of placentals (Springer et al, 1997) provided further support for early divergence between mammal orders. Calibrations of complete mtDNA-sequence trees with dates for the earliest known(Palacocene) cetaceans also set the origin of primates at about 90 Mya (Arnason et al, 1998). The problem of bias in the fossil record must also be addressed. Modern primates are largely confined to tropical and subtropical forests of the southern continents. Yet the earliest known (Eocene) primates occur in the northern continents and show little overlap in distribution. The most plausible explanation is that probabilities of fossil preservation/discovery have been far higher in the north and that the record simply reveals a transitory northward expansion of essentially tropical/subtropical primates when temperatures were markedly higher in the Eocene. The early history of primates in the southern hemisphere remains virtually uncharted.

The Evolution of the Social Brain

Robin Dunbar
School of Biological Sciences, University of Liverpool, UK

Primates are distinguished from other groups of animals by the fact that they have unusually large brains for body size. This increase in brain size can largely be attributed to a disproportionate increase in the size of the neocortex (and in particular the prefrontal neocortex) rather than to an increase in the brain as a whole. This raises two key questions: (1) why did brain size increase in this way among the primates? and (2) what have been the consequences? In this lecture, I will show that the primary factor selecting for increased brain size seems to have been the need to evolve large cohesive social groups, and that this in turn was a reflection of the way primates try to deal with the problem of predation. However, not all primates are the same. At least three (and perhaps four) distinct grades in relative neocortex size can be identified among the primates, with prosimians and apes being at opposite ends of a continuum of grades. This raises a particularly interesting question: why did apes as a group opt for especially large increases in brain size? Finally, I will look briefly at some of the cognitive implications of large neocortices in primates and the way that some especially human cognitive traits such as theory of mind and language fit into the story.

The Osman Hill Memorial Lecture

Primate Comparative Anatomy and the Evolution of Reproduction

Alan Dixson
Zoological Society of San Diego, USA

Between the years 1953—1974 Osman Hill produced eight monographs on the comparative anatomy and taxonomy of non-human primates. His books, which contain numerous descriptions of the reproductive organs of primates, were written before the modern era of research on sperm competition and cryptic female choice. Many of the variations in reproductive morphology described by Hill, which he employed for taxonomic purposes, may now be re-interpreted in terms of their evolutionary significance. This lecture will deal with effects of sexual selection upon the evolution of the genitalia, secondary sexual characters (e.g. sexual skin) and patterns of copulatory behaviour in primates. It is well established that relative testes sizes are largest in primates (and other animals) where females mate with multiple partners, and where sperm competition is greatest. However, other components of the male’s reproductive tract, including the vasa deferentia, seminal vesicles, prostate, striated penile muscles and the penis itself, have also been moulded by sexual selection. The female’s reproductive anatomy and physiology may also influence which male is successful in fertilizing ova; it is this aspect of sexual selection which Eberhard defines as “cryptic female choice”. Much less is known about this potential avenue of sexual selection in primates, or in other vertebrates. However, there is some evidence that sexual skin swellings, present in chimpanzees and some of the Old World monkeys, might represent a case of sexual selection by cryptic choice. This hypothesis will be evaluated as part of the lecture. All these ideas and advances owe much to the original comparative anatomical researches of Osman Hill, and his books continue to provide valuable facts and insights.

The Primate Mother-Infant Relationship: Causes and Consequences

Christopher Pryce
Behavioural Neurobiology Laboratory, Federal Institute of Technology, Zürich, Switzerland

Primate mothers invest considerable time and energy in a small number of offspring. The neurobiological regulation of their maternal behaviour is important in terms of offspring survival. Furthermore, if the social environment of offspring influences their neurobiological maturation, then maternal behaviour and its regulation are also important in terms of long-term offspring development. A model of maternal motivation proposed that pre-reproductive learning about infants and peripartum neurobiological changes are both important determinants of primate maternal behaviour. Studies in marmosets and tamarins, rhesus macaque and gorilla provide empirical support for the model. The model proposes that the emotional systems of attraction by and anxiety about specific infant stimuli (visual, auditory) increase maternal motivation whereas aversion and neophobia to specific infant stimuli (olfactory, tactual) decrease maternal motivation. Net maternal motivation is determined by pre-reproductive experience and peripartum neurobiology both acting on these systems. Furthermore, these four emotional systems have been incorporated recently into models aimed at elucidating the genetics of human maternal motivation, thereby demonstrating the biomedical importance of comparative neurobehavioural research. Cultural determinants of maternal behaviour and offspring development such as societal-level goals and rules are both important and unique to the human species and cannot be studied (modelled) in any other species. Animal models can however provide valuable insights into the importance of maternal care for the development of emotional and cognitive functions in human offspring, where these functions are similar in humans and other mammals. It is claimed that the rat, despite its very different life-history strategy, provides a valid model of the effects of impoverished maternal care on long-term neurobehavioural development of offspring, particularly in terms of emotional systems, but the current evidence is equivocal. Studies are now on-going in the common marmoset, to investigate the long-term effects of the infant-caregiver relationship on neurodevelopment and the suitability of this approach for modelling human neuropsychiatric disease.

Field Endocrinology:Studying hormone-behaviour interactions of primates in the wild

J.K. Hodges, M.Heistermann and T. Ziegler
Department of Reproductive Biology, Deutsches Primatenzentrum, Göttingen, Germany

Field endocrinology has been recently described as a focus in primatology and behavioural ecology that permits examination of social/reproductive behaviour and life history through hormonal investigations in natural settings (1). It is an area currently experiencing considerable growth, largely due to the extended opportunities for study provided by recent advances in non-invasive methodologies. In this way, use of faecal hormone analysis to generate hormone profiles from free-ranging animals, provides new opportunities for exploring proximate mechanisms underlying behavioural variation and for testing hypotheses concerning the functional and evolutionary significance of primate mating strategies.
This contribution will briefly outline the methods involved in faecal hormone analysis and illustrate their application with reference to our recent studies of reproductive strategies in free-ranging Hanuman langurs. Using an integrated approach combining behavioural, endocrine and genetic methodologies we have examined i) the relationship between patterns of ovarian cyclicity, behavioural receptivity and physical condition, and ii) sexual behaviour in relation to time of ovulation and subsequent paternity in seasonally breeding langurs living in Ramnagar. Results of the first part of the study indicate that proximate mechanisms regulating seasonal reproduction involve ecologically-mediated onset of ovarian activity and that timing of births is a secondary consequence of seasonal changes at the ovarian level. The second provides the first direct evidence that extended periods of receptivity characteristic of Anthropoid primates are associated with a high flexibility in timing of ovulation and related to a female strategy to influence paternity outcome.

(1) Whitten et al (1998) Yearbook of Physical Anthropology, 41 1-23.

Social and Genetic Structure of Polygynous Lemurs

Peter M. Kappeler
Dept. Behavior & Ecology, Deutsches Primatenzentrum, Göttingen, Germany

Because lemurs have been isolated on Madagascar for more than 50 million years, they provide an opportunity to identify fundamental mechanisms and patterns in primate social evolution through comparison with other primates. Lemurs evolved all basic types of primate social systems, but details of their social structure, as well as behavioral and morphological correlates of polygynous mating systems, deviate from those of the better-known anthropoids and prosimians. Most of these apparently non-convergent traits are subject to intrasexual selection and therefore raise questions about lemur life histories and mechanisms of male reproductive competition. I studied the social and mating systems of several solitary and group-living polygynous lemurs in Kirindy forest, Western Madagascar, to provide a basis for preliminary answers to these questions. Specifically, several hundred individually marked individuals were regularly re-captured and observed over several years to characterize their social system. Furthermore, genetic analyses of variation in mitochondrial DNA and microsatellite markers permitted illumination of population genetic structure and variation in individual reproductive success. For Mirza coguereli, these data revealed that solitary individuals are organized into extended matrilines and that their mating system is best characterized as scramble competition polygyny. In Propithecus verreauxi, small social groups are characterized by female philopatry and even sex ratios. Male reproductive success in this species is highly skewed towards the dominant resident male. These preliminary data therefore helped to identify similarities with other primates in fundamental life history traits, confirmed predictions about the mating system in the solitary species, but they provided no answer for the lack of convergence in several sexually selected traits of the group-living species. This indirectly supports the hypothesis that diurnal group-living lemurs are in a state of evolutionary disequilibrium.

Deconstructing Monogamy: Thailand’s Gibbons at Khao Yai

Volker Sommer1 and Ulrich Reichard2
1 Department of Anthropology, UCL, London, UK
2 Max-Planck-Institut für Evolutiondre Anthropologie, Leipzig, Germany

The traditional view of gibbon social organization emphasises that (a) they live in nuclear families of 2-6 members, (b) the breeding pair maintains a lifelong, sexually monogamous relationship, (c) they are quintessentially territorial. This view is challenged, both on theoretical grounds and with data from a long-term study on white-handed gibbons (Hylobates lar) in Thailand’s Khao Yai rainforest. Here, group ranges overlap considerably and encounters are not only agonistic but contain various affinitive behavioural pattern such as play. The term “territory” does not seem to reflect this situation properly. Similarly, “monogamy” is often employed without clear reference to the levels of grouping, mating or breeding although these dimensions do not necessarily correspond. The concept of a rigid grouping monogamy in gibbons is increasingly challenged by reports of partner changes (serial monogamy; at Khao Yai, not a single group with known history maintained lifelong grouping monogamy), and non-monogamous groupings (polyandry, polygyny or polygynandry in about one fifth of all groups). There is also increasing evidence for extra-pair copulations which may reflect a female strategy to confuse paternity and forestall infanticide. Thus, gibbon social organization is much more flexible than previously thought.

Managing Conflict in Group-Living Primates

Filippo Aureli
School of Biological and Earth Sciences, Liverpool John Moores University, Liverpool, UK

Conflict between group members is a natural outcome of competition for resources and co-ordination of activities. The escalation of conflict, however, can have detrimental consequences for the individuals involved and jeopardise co-operation that relies on their relationships. It follows that mechanisms of conflict management should be a critical component of the social life in any group-living species. During the last two decades a growing research effort has focused on the study of these mechanisms in non-human primates. The behaviour that has been most intensively studied is ‘reconciliation’, i.e. a friendly reunion between former opponents soon after an aggressive conflict. There is strong evidence for post-conflict reunions in the vast majority of the species studied both in captivity and in the wild. Researchers also demonstrated that these reunions function in repairing social relationships and found great variation in their frequencies across dyads of the same group, across groups of the same species, and across closely related species. These findings suggest that conflict resolution occurs more often in more valuable relationships. The involvement of third parties during and after an aggressive conflict has been widely reported, but the study of the conflict management function of triadic interactions is still at an early stage. Reducing the probability of escalation is certainly a more efficient way to manage conflict than repairing the damage afterwards. Mechanisms that aim to prevent the occurrence of an event (e.g. aggressive escalation) are, however, more difficult to study than the ones following an event (e.g. reconciliation). Thus, much less is known about the mechanisms to control aggression. A context in which these mechanisms have been extensively studied is crowding. Primates successfully cope with crowded conditions, and different mechanisms are used depending on the species and the duration of the condition.

Learning what to eat: The role of social influences in capuchins.

E. Visalberghi and E. Addessi
Istituto di Psicologia, Consiglio Nazionale delle Ricerche, Rome, Italy

Though feeding is crucial for survival we know little about how nonhuman primates learn what to feed upon and how they tune up their diet. According to Lee (1994) living in social groups affords the opportunity of exchanging information among individuals; consequently, living in groups, as most primate species do, can be of great advantage in learning when, how, and what to feed upon (e.g. Giraldeau, 1997). We investigated whether captive capuchin monkeys learn to assess food palatability from watching what conspecifics eat. Our previous experiments on capuchin monkeys demonstrated that they eat significantly more novel food when in the presence of group members provided with the same novel food. Group members potentially provide different sources of social influences; therefore, consumption could have been affected by the mere presence of group members (reducing an individual’s stress of being alone, or its neophobic response), by the fact that group members were eating (i.e. social facilitation of eating), or by which food they were eating (stimulus enhancement). We experimentally investigated the role of the above factors by assessing individual’s consumption of novel foods when the experimental subject was (1) alone with nobody in the nearby cage (Alone condition, A); (2) with group members present in the nearby cage with no food (Presence condition, P); (3) with group members present and eating a familiar food whose colour is different from that of the novel food (Presence plus different-Food condition, PdF); and (4) with group members present and eating a familiar food whose colour is the same as the colour of the novel food (Presence plus same-Food condition, PsF). The subject was separated from group members by a Plexiglas panel which allows them to see each other. Results showed that frequency of eating behaviour and grams of food ingested were significantly higher in the PsF and the PdF conditions than in the A and in the P conditions. Moreover, the frequency of eating was significantly higher in the PsF condition than in the PdF condition, although the amount of food ingested was not. The increased consumption recorded in the PdF condition indicate that eating behaviour is socially facilitated regardless of the visual appearance of the food eaten by group members. The results obtained in the PsF condition suggest that stimulus enhancement does not affect the amount of food ingested, although it slows down eating behaviour.
Since only social facilitation of eating the same food eaten by group members can be considered a safe way to learn about a safe diet, we should conclude that capuchins do not learn whether a novel food is palatable from watching what group members eat. Social facilitation of eating a novel food when group members are eating a different food, however, may be considered a quicker way to overcome neophobia. Future studies should investigate whether social influences on learning derive from the opportunity of tasting what group members are eating.

Giraldeau, L.A. (1997) The ecology of information use. In J. Krebs and N. Davies (eds) Behavioral Ecology, 4th edition, Blackwell Science, Oxford, pp.42-68.

Lee, P.C. (1994) Social structure and evolution. In P.J.B. Slater and T.R. Halliday (eds) Behaviour and Evolution, Cambridge: Cambridge University Press, pp.266-302.

The colobus of the Taï Forest: three ways of making a living

Ronald Noë
Laboratoire Ethologie des Primates, Université Louis-Pasteur, Strasbourg, France and Max-Planck-Institute Seeweisen, Starnberg, Germany.

Three species of Colobus-monkeys share the same environment, the tropical moist forest of the Taï National Park of Ivory Coast: the western red colobus ((Pro)Colobus badius); the olive colobus ((Pro)Colobus verus) and the western black & white or king colobus (Colobus polykomos). These species have many common characteristics, the most significant of which is perhaps a multi-chambered stomach which makes it possible to digest leaves. In spite of a common ancestor and environment the three species show striking differences in body size, group size, mating system, dispersal pattern, anti-predation defence strategies and a number of other characteristics. The accepted way of explaining such differences is to start from differences in diet. Diet is assumed to be the ultimate cause of a cascade of further cause and effect relationships. For example: differences in food distribution lead to different levels of competitive aggression, causing differences in payoffs from coalition formation, which in turn select for different forms of dispersal behaviour, which leads to differences in kinship structure etc. Many hypotheses based on this scenario have been tested and the general line of reasoning found considerable support. However, a key question has generally been ignored: Why do such sympatric and congeneric species have different diets? Is this a matter of niche differentiation due to inter-specific competition? Or do causal arrows run back from characteristics such as group size or anti-predation defence? I will argue that the complex of different characteristics of a species hang together by a network of causal relationships forming an ‘adaptive syndrome’ at which each of the three species arrived from a common starting point along a spiral-like pathway that included several feedback loops. Diet can cause group size as much as the other way around. It therefore makes more sense to explain why some syndromes are more likely than other than engaging in circular arguments about the starting points of feedback loops.

Primates, People and Development: Conservation Challenges in Gabon

Caroline E.G. Tutin
Centre International de Recherches Médicales de Franceville, Franceville, Gabon, and Dept of Biological and Molecular Sciences, University of Stirling, Scotland

Gabon, a country slightly larger than Great Britain with a population of 1.2 million, straddles the equator on the coast of West Africa. About 80% of the country is covered by tropical forest, and three-quarters of the population live in towns or cities. Nineteen species of diurnal primate occur, including the endemic Cercopithecus solatus and significant populations of Colobus satanas, Mandrillus sphinx, Pan t. troglodytes and Gorilla g. gorilla. Hunting to supply commercial urban markets is the greatest threat to primates. As yet, there are no National Parks in Gabon, but four large Faunal Reserves cover about 10% of the country’s area. Compared to neighbouring countries, per capita income in Gabon is high as exploitation and exportation of mineral resources provided substantial wealth during the past 30 years. However, oil and uranium reserves are now dwindling and the extraction of timber will be the mainstay of future economic development. Logging is highly selective and considerable efforts are being made to introduce “reduced impact logging” techniques such that timber is harvested in a sustainable manner. The link between logging and the bushmeat trade is clear, as access and transport are the major factors that encourage commercial hunting. Present levels of hunting are clearly unsustainable but current management of timber forests does not include control or monitoring of hunting. The potential remains in Gabon to apply a landscape approach to conservation and development, but changes in attitudes, legislation combined with an engagement of grass root support are essential. Is it possible to achieve such changes, or is a slide towards a fragmented landscape where Protected Areas are the only places where primates remain, inevitable?

Advances in Studies Linking Social Behaviour with Genetic Structure in Non-human Primates

M.W. Bruford1 and M.K. Bayes2
1 Cardiff School of Biosciences, Cardiff University, Wales, UK
2 Institute of Zoology, Zoological Society of London, London, UK

In the last five years, previously unimaginable detail has started to emerge from studies of wild primate populations, on the complex interactions involving social behaviour, mating patterns and genetic structure. Non-human primates exhibit a wide variety of social systems, the complexities of which have been studied in detail as part of some of the great longitudinal ecological studies of animal populations of the last forty years. Although most primates are social, contrasting patterns of mating behaviour, dominance, dispersal, group size and many other factors are found in different species, and even within the same species. These factors have made non-human primate studies both a major focus in evolutionary ecology and a potentially rich source of comparative data. Until recently, however, detailed studies of primate demographic patterns and their genetic impact have been confounded by inherent problems in measuring reproductive success, inclusive fitness, relatedness and genetic differentiation among social groups and populations. Primates have long been regarded as very difficult subjects for such studies due to the problems, both ethical and logistic, of taking samples invasively for genetic studies, and because of the perceived consequences of such actions on the behaviour of the study populations. The advent of non-invasive genotyping techniques in the last few years has changed this impasse. Through amplification of DNA from hair and faeces and with the availability, through the human genome mapping project, of vast numbers of polymorphic microsatellite systems for primates, significant advances have at last been seen in this field. In this talk I will outline some recent examples, from the work of ourselves and others, of how such studies are changing some of the paradigms within primate evolutionary ecology, and how the elucidation of increasingly fine-scale patterns of genetic structure within primate communities may enable us to solve some of the puzzling complex social structures which seem commonplace in apes and monkeys.

Jan van Hooff (Universiteit Utrecht, The Netherlands) and Susie Utami Atmoko (Universitas Nasional, Jakarta, Indonesia). Their title is: “Two of a kind: Alternative sexual strategies of adult male orangutans”. Abstract not available.

Please note that a proposed talk by Annie Gautier-Hion will be replaced by that of Anthony Rylands.

Primate Conservation – Global Patterns, Hotspots and Wilderness areas

Anthony B. Rylands and William R. Konstant
Conservation International, Washington, D. C. USA

A recent taxonomic evaluation of the diversity of non-human primates has indicated at least 601 distinct taxa, classified into 66 genera in 15 families, and approximately 293 species. Of these, 51 (8.5%) occur in Madagascar, 163 (27%) are African, 183 (30.5%) are Asian, and 204 (34%) occur in the Neotropics. Primates occur in 92 of the world’s 213 sovereign countries, but just four (Brazil, Democratic Republic of Congo, Indonesia and Madagascar) account for two-thirds of them. According to the 2000 Red List of Threatened Animals of the IUCN Species Survival Commission, 137 primates (23%) are currently “Critically Endangered” or “Endangered”. Prioritization is necessary in that the number of species threatened with extinction far outstrips the resources available for their conservation. The IUCN/SSC Primate Specialist Group, in collaboration with Conservation International, Washington, DC, is currently drawing up a major action plan for the Critically Endangered and Endangered primates. The analysis of global patterns of threats to primates in this action plan uses the biogeographic constructs of “hotspots” (extremely threatened areas of exceptionally high biodiversity and numbers of endemic species), and two “tropical forest wilderness areas” (species-rich areas which although highly threatened, are still largely intact – the Amazon and the Congolean Forests) (N. Myers et al., Nature, Lond. 403: 853-58, 2000). Primates occur in 15 of the 25 hotspots, and 147 (50%) of the species are endemic to one or more of them: of these, 112 are “Critically Endangered” or “Endangered”. The Amazon wilderness area takes in a further 59 endemic species and the Congolean forests a further nine. The major threats, and strategies for the conservation of the habitats for the primates in the wilderness areas and hotspots, will be discussed.

EFP 2000 - WORKSHOPS

Monday 27 November, 2000

ABSTRACTS

Prior to the invited speakers conference at the ZSL, workshops will be held at Goldsmiths College and the University of Surrey, Roehampton.1. Genetics and Evolution – Jan de Ruiter (University of Durham, UK) & Nick Mundy (University of Oxford, UK)

The combination of modern molecular genetics and new analytical methods herald an exciting time for primatology, from the level of intragroup relationships up to macroevolutionary patterns. In this workshop we will concentrate on some recent innovations in this field. Areas for discussion will include relatedness, population genetics and adaptive molecular evolution. As well as welcoming those with a general interest in the field, the workshop will provide an opportunity for people with their own datasets to bring them along.

2. Simian Viruses – Myra McClure (Imperial College Schhool of Medicine, London, UK) and David Brown (Public Health Laboratory Service, Colindale, London, UK)
Through lecture and discussion, this workshop will look at the following questions: which retroviruses affect primates? What are the effects of these infections? How can we test for retrovirus infections? How can we best deal with the infections?

3. Use of Primates in Research – Bertrand Deputte (Université de Rennes, France) and Mark Matfield (Research Defence Society, London, UK)
This workshop will consider the use of non-human primates in both fundamental and applied science, with particular emphasis on the ethical and welfare aspects. It will consist of short lectures from invited speakers, leading into a general workshop discussion of the issues raised.

4. Cognition & Social Complexity – Felippo Aureli (John Moores University, UK) and Robin Dunbar (University of Liverpool, UK)
This workshop will cover theoretical, empirical and methodological issues in primate cognition and social complexity. Lecture and discussion sessions will deal with explanations of why primates have large brains, the complexity of primate social interactions, and the cognitive abilities associated with the regulation of social relationships.

5. Ecology and Sociality – Phyllis Lee (University of Cambridge, UK) and Volker Sommer (University College London, London, UK)
This workshop will cover a range of topics such as female kin-bonding, mechanisms of competition, the role of males and mating systems in structuring social systems and predation. It will also consider the methodological problems of quantifying diet and food patches, activity budgets and time constraints, and grooming and social contests. Short (10 minutes maximum) presentations by participants are welcome.

6. Behavioural and Physiological Development – Debbie Curtis1, Ann MacLarnon1, Christopher Pryce2 & Jo Setchel1
1 (University of Surrey, Roehampton, UK)
2 (Swiss Federal Institute of Technology, Zürich, Switzerland)
This workshop is for people interested in both field and captive applications of behavioural and physiological techniques for studying ontogeny – from conception through gestation and postnatal development. Approaches to be considered include salivary, blood, urine and faecal assays, telemetry, behavioural observation and the comparative method. Participants will be able to discuss the suitability and limitations of different techniques in field and captive settings.

ABSTRACTS FOR POSTER PRESENTATIONS

Local sexual competition rather than sperm competition in a nocturnal prosimian? Evidence from genetic determination of paternity in captive grey mouse lemurs

Marjorie Andrès1, Hélène Gachot-Neveu2, Martine Perret1
1CNRS UMR 8571, Laboratoire d’Ecologie Générale, 4 av. du Petit Château, F-91800 Brunoy
2Laboratoire de Biologie, Centre de Primatologie, Fort Foch, F-67207 Niederhausbergen
E-mail: ecotrop@cimrs1.mnhn.fr

Among nocturnal Malagasy prosimians, the grey mouse lemur (Microcebus murinus) is considered a solitary species having a promiscuous mating system. Indirect evidence such as the lack of sexual dimorphism, the high relative testes size of males and the high synchronism in estrus occurrence among females support the presence of sperm competition. In captive animals, we used genetic determination of paternity to define the relationship between social rank and reproductive success of males kept in groups with several females during the mating period. Within each group, intense sexual competition arose among males for priority of access to estrus females. High ranking males, determined from the direction of agonistic interactions, have significantly higher mating success than subordinated males. A high ranking position is associated with a higher frequency of marking behaviours and of chemosensory investigations of females. Moreover, the rank difference in aggressive behaviours of females in response to male sexual solicitations suggests that females could exert a choice. A robust relationship was found between male rank and reproductive success since 33 out of the 35 offspring produced have been sired by the highest ranked male of each group. Local sexual competition rather than sperm competition seems to be prevalent in mating system of the grey mouse lemur. In this nocturnal arboreal species, olfactory signals, rather than size or morphological traits might be favored by sexual selection and might be used for both sexual coordination between sexes and partner choice.

The Darwin initiative in the Gabon: molecular ecology and conservation of western lowland gorillas

Nicola Anthony1, Mireille Johnson-Bawe2, Kathryn Jeffreys1, Jean Wickings2, Kate Abernethy2, Lee White3 and Michael Bruford1
1Cardiff University School of Biosciences
2Centre International de Recherche Medicale, Franceville, Gabon
3Wildlife Conservation Society, New York
E-mail: Anthonynm@cardiff.ac.uk

The principle research objective of this three year collaborative effort is to examine patterns of genetic variability in western lowland gorillas at different geographic scales. Gabon harbors some of the largest population densities of the western lowland gorilla, yet little is known of the genetic structure of natural populations. Building on a recently completed pan-African study of gorilla genetic variation, we are currently in the process of sampling gorilla hair and faecal material from a network of candidate protected areas throughout Gabon. Protocols for the successful amplification of mitochondrial and microsatellite genetic markers from shed hair and faeces have been established. In addition to basic research, there are several other activities that form an equally important part of this program. In the past year, the Darwin initiative has been responsible for (1) within country technical training (2) transfer of appropriate molecular technologies and (3) development of an introductory course in conservation biology at the National Science University in Franceville, Gabon.

Non-invasive monitoring of reproductive status in wild mongoose lemurs (Eulemur mongoz): an investigation of faecal steroid excretion patterns

D. J. Curtis1, A. Zaramody2, D. I. Green1, A. R. Pickard1
1Institute of Zoology, Zoological Society of London, Regent's Park, London, UK
2Département des Sciences de la Terre, Université de Mahajanga, Mahajanga, Madagascar
E-mail: d.curtis@roehampton.ac.uk

The non-invasive monitoring of reproductive events in females is vital to the conservation, captive management and breeding of endangered species. This study focused on Eulemur mongoz in one of the first attempts at monitoring reproductive parameters in faeces collected from wild lemurs (n=4). The aims were: (1) To establish which oestrogen and progestagen metabolites occur in the faeces using Gas Chromatography - Mass Spectrometry (GC-MS). (2) To monitor ovarian function and pregnancy by measuring faecal steroids using a total oestrogen and a 20a-dihydroprogesterone enzymeimmunoassay (EIA). Oestrogen concentrations were too low to be detected by GC-MS, while progestagens were present in detectable quantitites (breeding season: 5,16-pregnen-3b-ol-20-one; pregnancy: 5b-pregnan-3b-ol-20-one). Characterization of the hormone cycle was not possible, due the occurrence of pseudooestrus prior to first oestrus and conception at first ovulation. Detection of ovulation was possible if the sampling frequency was high enough and the ratio oestrogens / progestagens was determined. The first 91 and 111 days of pregnancy were monitored in two adults. Pregnancy in a subadult was terminated after 70-80 days. Pregnancy was reliably determined 40-50 days after conception, when progestagen and oestrogen excretion increased above breeding season concentrations.

Ecology, social structure, and inter-sexual differences in free-ranging mantled howler monkeys (Alouatta palliata) on Ometepe island (Nicaragua)

C. Devos1, M.-C. Huynen1 and P.A. Garber2
1Department of Ethology, University of Liege, Belgium
2Department of Anthropology, University of Illinois, USA
E-mail: celine_devos@hotmail.com

From February through May 1999, we conducted a field study of the behaviour and ecology of a group of mantled howler monkeys at the Ometepe Biological Research Station, Nicaragua. The focus of this research was to examine evidence of intersexual differences in behaviour, and the degree to which female reproductive state influenced male and female social interactions. A total of 350h of data were collected on the activity budget, diet, and social interactions of adult group members using a 2 min instantaneous and a 90 min focal animal sampling technique. Sex-based differences in behaviour were examined using a chi2 test. The results indicate that males rested significantly more, fed less, and consumed more leaves and fewer flowers than did females. Males also spent more time than females in affiliative and sexual interactions, principally with other males and with females without offspring. Females without offspring were the preferred interactants for other females, but none of these differences were statistically significant. Variation in subgroup size and composition throughout the study strongly suggests that these howlers maintain flexible patterns of social spacing and troop cohesion, probably related to food distribution and fragmentation of the habitat.

The adaptation of reintroduced chimpanzees to continuous forest in the Conkouati Reserve, Republic of Congo

K.H. Farmer1, A. Jamart2 and H.M Buchanan-Smith1
1Scottish Primate Research Group, Department of Psychology, University of Stirling, Stirling FK9 4LA, Scotland
2Habitat Ecologique et Liberté des Primates, BP. 335, Pointe-Noire, Republic of Congo, Central Africa
E-mail: k.h.farmer@stir.ac.uk

Since 1996 the non-governmental organisation, Habitat Ecologique et Liberté des Primates has reintroduced 22 chimpanzees (6 males and 16 females) back to the wild. Sixteen of these have survived, four have disappeared (status unknown) and two are known to have died. The five chimpanzees that were released in 1996 are all in good health and have been nutritionally self-sufficient since day one post-release. Activity budgets are comparable to those in wild populations and the ‘reintroducees’ eat a similar range of leaves, stems, fruits and insects. Here we focus on one skill necessary for the successful adaptation of the reintroduced chimpanzees: nest building. The fabrication of nests is a feature of wild chimpanzee behaviour and may be a critical variable on the health and survivorship of chimpanzees in offering protection from predators and the elements. Like their wild con-specifics, the released chimpanzees built their nests in groups, high in trees. Such differences as were found could largely be attributed to environmental factors and the semi-restrictive pre-release environment. However, the pre-release island environment provided the chimpanzees the opportunity to develop and practise nest-building skills. As a consequence they were able to build fully functional nests immediately post-release.

The ability to follow eye gaze and its emergence during development in macaque monkeys

P.F. Ferrari, E. Kohler, L. Fogassi and W. Gallese
Instituto di Fisiologia Umana and Instituto di Psicologia, Universita di Parma, via Volturno 39, 43100 Parma, Italy
E-mail: ferrari@biol.unipr.it

The ability of monkeys to follow the gaze of other individuals is a matter of debate in many behavioral studies. There is little evidence at the behavioral level of the presence and development of such abilities in monkeys. The aim of the present study was to assess in juveniles and adult pig-tailed macaques (Macaca nemestrina) the capacity to use eye cues alone to follow the gaze of an experimenter. Biological stimuli (head, eye and trunk movements) were presented by an experimenter to 11 captive monkeys of different age. A non-biological stimulus served as a control. Results showed that macaques can follow the gaze of the experimenter using head/eyes or eye cues alone. Trunk movements and non-biological stimuli did not significantly elicit similar reactions. Juvenile monkeys were not able to orient their attention on the basis of eye cues alone. In general, gaze following was more frequent in adults than in juveniles. However, similarly to humans, such abilities in macaques dramatically improve with age suggesting that the transition to adulthood is a crucial period in the development of gaze following behavior.

Vocal repertoires and classification of vocalisations in 5 Eulemur species

Marco Gamba and Cristina Giacoma
Dipartimento di Biologia Animale e dell'Uomo, Via Accademia Albertina 17, I-10100, Torino, Italy
E-mail: LEGITO@rocketmail.com

Results of a comparative acoustic analysis of vocalisations in 5 Eulemur species (Eulemur rubriventer, Eulemur macaco (E. m. macaco and E. m. flavifrons), Eulemur coronatus, Eulemur mongoz, Eulemur fulvus (E. f. albifrons and E. f. mayottensis) are discussed in this work. Digital audio and video recording of the naturally occurring vocalisations of 17 captive groups of lemurs were collected at: Parco Natura Viva-Garda Zoological Park (Bussolengo-VR, Italy), Mulhouse Zoo (Mulhouse, France), Koln Zoo (Koln, Germany), Apenheul (Apeldoorn, The Netherlands). A detailed acoustical analysis was performed in order to classify emitted vocalisations using seven acoustic parameters (dominant frequency, four spectrum peaks, index of formant dispersion, duration) to generate data to compare species and subspecies emissions. Processing of seven acoustic parameters (dominant frequency, four spectrum peaks, index of formant dispersion, duration) for ‘Grunt’ vocalisations, present in the repertoire of all the species, has shown that it is possible to elaborate a tentative phylogeny of lemurs based on the acoustic structure of their vocalisations. Multivariate PCA and Discriminant analyses were reliable for categorising 'long grunts' and 'grunts' in most species. Most of the non-tonal emissions of the study species could be categorised. Using a larger set of acoustic parameters we have been able to discriminate between modulated and stable tonal emissions.

This work was supported by Parco Natura Viva – Garda Zoological Park.

Cheek pouch use and Concurrent Behaviour: Implications for Activity Budgets Models

V. Gutierrez-Diego
Universidad Complutense, Madrid, Spain and Life Sciences, Anglia Poly. University, East Road, Cambridge CB1 1PT
E-mail: viki@freenet.co.uk

The ability of all cercopithecines to consume food while engaged in other activities is an adaptation that has been greatly overlooked and its importance to time budget models has been disregarded. This study was conducted on a troop of yellow baboons (Papio cynocephalus) in Mikumi National Park, Tanzania as part of a comprehensive research project on cheek pouches. Preliminary analyses reveal more than a 32% increase of the feeding time budget category when cheek pouch use is included. Cheek pouch chewing is conducted simultaneously with other behaviours 12% of the time. Conventional time budget studies have considered pouch emptying as a resting behaviour, and as a consequence resting time budgets have been overestimated.

A new behaviour in Garnett's greater bushbabies (Otolemur garnettii): Foot-rubbing as a multifunctional form of communication

Reinmar Hager
Department of Zoology, University of Cambridge, UK
E-mail: rh244@cam.ac.uk

Garnett's greater bushbabies exhibit a curious behaviour that has, to my knowledge, not yet been reported and analysed. By rubbing a part of their foot on wood or on other substrates they produce a scraping noise which probably serves as a multifunctional form of intra-specific communication. The particular area on the feet is characterised by much tougher skin which can grow to extensive horn-like structures. Both males and females have this region of tough skin on their feet which is free of glands. In this study I observed and recorded the behaviour of captive Garnett's greater bushbabies. Males exhibited foot-rubbing significantly more often than females both when housed individually and in pairs. In general, the level of foot-rubbing was lower when the animals were housed as individuals. This behaviour occurred in the context of different situations. Females usually exhibited foot-rubbing after they were approached by males and after agonistic interactions. Males also exhibited this behaviour in agonistic interactions as well as when following females and in response to another male foot-rubbing. These observations suggest that this behaviour has multiple functions in communication but apparently does not serve a marking function. Foot-rubbing produces a noise that may be indistinguishable from background noise to other animals. The bushbabies may indicate their presence to conspecifics or potential mating partners without revealing their presence to predators. The fact that foot-rubbing is exhibited by both sexes in agonistic interactions may indicate a further aspect of this behaviour. The closely related species Galago crassicaudatus does not have this characteristic region on their feet and I have not observed a similar behaviour in previous studies of other species.

Causes and Consequences of Troop Fusion in the Mikumi Yellow Baboons (Papio cynocephalus)

D.M. Hawkins1,2, G.W. Norton1,2 and P. Cunneyworth2,3
1Environmental Sciences Research Centre, Anglia Polytechnic University, East Road, Cambridge CB1 1PT. Tel 01223 363271 ex 2282; Fax 01223
2Animal Behaviour Research Unit, Mikumi National Park, Tanzania
3ELCI, Nairobi, Kenya
E-mail: d.hawkins@anglia.ac.uk

Halfway through a two year study of the time budgets of yellow baboons (Papio cynocephalus) in Mikumi National Park the two main study groups fused. This provided a fortuitous opportunity to investigate the immediate consequences of a sudden doubling of group size on individual behaviour. From these results, and other observations made at the time of the fusion, it is possible to suggest factors promoting this fusion event in Mikumi National Park. As a consequence of the troop fusion, individuals gained foraging benefits without incurring costs of increased intragroup competition and were relieved of serious time budget constraints. Decrease in intertroop competition appears to have been an important factor in these benefits. Anti-predator benefits may have played a role in facilitating both the fusion event and the subsequent exploration of new areas by the resultant single larger troop. Undoubtedly, a variety of ecological factors created a situation in which individuals could gain these net benefits by fusing with another troop. This coincided with the occurrence of demographic conditions which made fusion possible.

Mother-infant relationships in development: a growth-modelling approach to the study of change

M.V. Hernández-Lloreda1 F. Colmenares2, R. Martínez-Arias1
1Departamento de Metodología de las Ciencias del Comportamiento
2Departamento de Psicobiología, Facultad de Psicología, Universidad Complutense de Madrid, Campus de Somosaguas, 28223 Madrid, Spain
E-mail: colmenares@psi.ucm.es

Mother-infant relationships represent developing (social) systems which can be used to analyse the nature of change during early ontogeny. In this work, a two-level, growth modelling approach was used (1) to determine the mathematical functions appropriate to describe the individual growth trajectories of baboon subjects over their first year of life and (2) to analyse interindividual differences in developmental trajectories as a function of the infant´s sex and the mother´s age and reproductive experience. Data on measures of proximity, affiliation, maternal rejection, maternal restraint and infant anxiety were collected during 25 fortnight periods from birth onwards for 23 mothers and their infants from the Madrid colony of hamadryas baboons (Papio hamadryas). The developmental trajectories of most behavioural measures were curvilinear and could be classified into a reduced number of patterns of change. The approach proved very useful to quantitatively deal with issues of initial status, rate of change, differentiation and canalization in development, and continuity of outcome versus underlying processes. The infant´s sex and the mother´s age and reproductive experience accounted for part of the variation in developmental pathways. The mother´s resumption of oestrus seemed to act as a major disturbance and as a factor canalizing the individuals´ ontogenetic trajectories.

Investigation into the cultural and ecological factors leading to differences in behaviour among three neighbouring populations of West African chimpanzees (Pan troglodytes verus)

Tatyana Humle1, Tetsuro Matsuzawa2
1University of Stirling, UK
2KUPRI (Kyoto University Primate Research Institute), Japan
E-mail: tatyanahumle@hotmail.com

Field studies of chimpanzees (Pan troglodytes) have revealed distinctive differences in behavioural repertoire suggesting significant cultural variation across populations and communities. Systematic synthesis of these cultural variants has recently been accomplished based primarily on information acquired from long-term field studies of chimpanzees across Africa. Further investigation is needed into the processes and mechanisms of transmission taking place and into the shape and form of these cultural variants in wild chimpanzee populations. A long-term project of Kyoto University Primate Research Institute (KUPRI) aims to address these issues. This project is being carried out in an area incorporating Bossou, Guinea and both sides of the Nimba Mountains (straddling Guinea and the Côte d’Ivoire), and surrounding regions. A small population of chimpanzees can be found at the Bossou site, which was set up in 1976 by Sugiyama, KUPRI, and at least three groups reside at the Nimba sites, which were both only recently established. In collaboration with researchers and students from KUPRI, we have begun to explore differences in chimpanzee material culture, nesting behaviour and feeding repertoire between Bossou, Nimba and the surrounding regions. These include differences and similarities in the use of a similar resource, the oil-palm tree (Elaeis guineensis), found at all three sites, in nut-cracking behaviour with regards to target nut species being cracked and in tool-choice for ant-dipping. These will be discussed briefly in the context of ecological differences between these sites and the inter-populations dynamics of these neighbouring populations of chimpanzees.

Pseudoestrus in pregnant Hanuman langur females: functional explanations

Stanislav Lhota1, Jan Havlí_ek2, Lud_k Barto_3
1Department of Zoology, Charles University, Vini_ná 7, 128 44 Praha 2, Czech Republic
2Department of Philosophy and History of Natural Sciences, Vini_ná 7, 128 44 Praha 2, Czech Republic
3Research Institute of Animal Production, P_átelství 815, Praha 10 – Uh_ín_ves, Czech Republic
E-mail: stanlhota@yahoo.com

Female Hanuman langurs often come into estrus during pregnancy. Such behavioral pseudoestrus takes a very different form from the ovulatory estrus of non-pregnant females, and thus is not likely to be a mere tailing off of pre-conception cycles. We review two hypotheses explaining the possible function of this phenomenon. The first one explains pseudoestrus during pregnancy as an infanticidal counterstrategy. Contrary to previous findings from Jodhpur, our data from Bhangar show that the occurrence of pseudoestrus is influenced by male membership changes in the troop, thus giving support to the first hypothesis. On the other hand, neither our data nor those from Jodhpur and/or from Ramnagar show any effect of copulations of a new harem holder with a pregnant female on the risk of infanticide. Alternatively, according to the second hypothesis, copulations with extratroop males may be important, and proceptive behavior of pregnant females may serve to reduce males’ aggression and/or females’ stress and thus possibly also the risk of abortion.

Relatedness and cooperation: a genetic and behavioural study of the wild Hanuman langur, Presbytis entellus

Katherine Little1, Volker Sommer1, and Mike Bruford2
1Department of Anthropology, University College London
2School of Biosciences, Cardiff University
E-mail: littleka@Cardiff.ac.uk

The Hanuman langur (Presbytis entellus) is a classical sociobiological study species. Native to the Indian subcontinent, it shows remarkable flexibility in its social organisation, from multi-male, multi-female groups to one-male, multi-female 'harems' and all male 'bachelor bands'. In the 2000 strong genetically isolated population of langurs surrounding Jodhpur, Rajasthan, the harem / bachelor band organisation accounts for 95% of groups. This research focuses on the relatedness of group members, in an attempt to provide evidence of a genetic basis for the differing levels of cooperation and conflict observed in matrilineal harems and the less closely allied male bands. Using extraction of DNA from faecal samples collected from members of 6 harems and 6 bachelor bands, individuals are genotyped using 10 human microsatellite markers. From these data it is possible to test the hypotheses concerned with varying levels of relatedness within and between different groups of individuals, such as that harems have a higher level of relatedness than the bachelor bands, due to female philopatry. Thus this study will compliment the three decades of behavioural studies carried out in Jodhpur, and help to elucidate the factors underlying the high degree of cooperative behaviours observed in the langurs.

Factors affecting the successful pairing of unfamiliar common marmoset (Callithrix jacchus) females

Bonaventura Majolo1, Hannah M. Buchanan-Smith1 and K. Morris2
1Scottish Primate Research Group, Department of Psychology, University of Stirling, Stirling, FK9 4LA, Scotland
2MRC Reproductive Biology Unit, Centre for Reproductive Biology, 37 Chalmers Street, Edinburgh, EH3 9ET, Scotland
E-mail: b.majolo@tiscalinet.it

Social housing in captivity is recommended for group-living primates, but the formation of new groups is not without risk. The individuals may be incompatible, and stress and injury may result. Although the procedures for creating new groups of macaques (Macaca spp.) are now reasonably well documented, there are no data available on factors affecting the success rate for pair formation in female marmosets. Same sex aggression between unrelated females is well documented in marmosets, yet laboratories frequently require individuals of the same sex to be housed together to prevent breeding during experimental procedures. In this study, data on the formation of 46 common marmoset (Callithrix jacchus) female pairs in a laboratory were analysed. The success rate was 83%. The age of the females appears to be a critical factor in success rate, and aggression is lower if one member of the pair is not yet sexually mature (i.e. < 12 months). The results of this study show that pairing unfamiliar common marmoset females can be accomplished safely to avoid single housing when natural social grouping is not feasible.

Comparison of locomotion and behaviour in captive common chimpanzees

Richard Marvan
Charles University, Prague
E-mail: Vaclav.Vancata@pedf.cuni.cz

Patterns of locomotion and behaviour in 43 chimpanzees (Pan troglodytes) were investigated in Liberec and Dvur Kralove n/L. Zoos in the Czech Republic and in Chester Zoo, UK. All changes in locomotion (20 locomotor types) and behaviour (7 types) were recorded during 15 minute observation periods. The goals of the research were: 1) The analysis of locomotor and behavioural patterns in Pan troglodytes in captivity. 2) The comparison of locomotor and behaviour patterns in different zoos. 3) The investigation of the effects of variation in environment and social structure in different zoos. The occurrence of postural behaviours, and of terrestrial and arboreal quadrupedalism increases in all zoos during ontogeny. The frequency of other locomotor behaviours is greatest in juvenile and subadult individuals and lowest in adults. Dynamic forms of play and agonistic behaviours decreased during ontogeny. Feeding and social behaviours increased with age in all chimpanzee groups studied. Significant sexual differences in the frequencies of behaviours were found among studied groups. Differences were also found between estrous and non-estrous females.

Why live with many males? The case of Eulemur fulvus rufus

Julia Ostner
Dept. Ethology and Ecology, German Primate Center, Kellnerweg 4, 37077 Goettingen, Germany
E-mail: jostn@www.dpz.gwdg.de

In gregarious mammals adult sex ratio is generally skewed towards females. Group living Malagasy lemurs deviate from this pattern by living in small multimale-multifemale groups with on average even sex ratios. Females may benefit from a high number of males in several ways: reduced between-group-competition and infanticide risk, help with paternal care, assistance with thermoregulation (huddling groups), and decreased predation risk through increased vigilance. To evaluate the hypotheses of thermoregulation and vigilance against predators, I observed 4 groups of redfronted lemurs (Eulemur fulvus rufus) in Kirindy, Madagascar from May 1999 to July 2000. Thermoregulation cannot explain the high number of males since surplus males did not necessarily participate in huddling groups. Throughout the year males spent significantly more time than females scanning the environment, implying a better protection against predators in groups with extra-males. The alternative explanations were not evaluated in this paper, but paternal care did not seem to play an important role, because males did not carry or feed infants. Infanticide has never been observed in Kirindy, but the rapid mode of male takeover, observed in 5 cases, makes infanticide at least possible. Many males may decrease the risk of takeover. Thus, increased vigilance and possibly better protection against takeover/infanticide are possible benefits for redfronted lemur females from living with many males.

Variability and sexual dimorphism in extant hominoids: the case of the genus Gorilla

Sandrine Prat
Collège de France, Laboratoire de Paléontologie et de Préhistoire, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05
E-mail: sandrineprat@hotmail.com

Gorilla gorilla is one of the most dimorphic living hominoid species. Until Groves' study in 1970, the genus Gorilla was divided into two distinct subspecies: G.g.gorilla (western lowland gorillas) and G.g.beringei (eastern or mountain gorillas). Groves proposed the subdivision of the eastern populations into two subspecies G.g.graueri (eastern lowland gorillas) and G.g.beringei (mountain gorillas). However, the mitochondrial DNA studies by Ruvolo et al. (1994) show large differences between the western and the eastern gorillas raising the possibility that these populations belong to distinct species. The aim of this study is to compare the variability and the sexual dimorphism of the young and adult specimens of Gorilla. Forty-nine specimens of known sex and locality have been studied. One hundred and forty-two cranial, dental and mandibular morphological traits and 156 measurements were analysed. The three subspecies of Gorilla are morphologically and metrically distinct. These results confirm Groves' findings. For most of the cranial variables, the adults of the subspecies G.g.gorilla appear to be the most dimorphic. Sexual dimorphism and overall variability are greater in G.g.beringei than the other populations for the upper teeth. However for the anterior lower teeth, except the canines, the eastern lowland gorilla exhibits the highest variability.

A complex kin-based nocturnal primate society: Matrilinear grouping patterns in the grey mouse lemur

Ute Radespiel1, Elke Zimmermann1, Mike Bruford2
1Institute of Zoology, Tieraerztliche Hochschule Hannover
2Cardiff School of Biosciences, Cardiff University, Wales, UK
E-mail: Ute.Radespiel@tiho-hannover.de

Within a dispersed social network female grey mouse lemurs regularly form stable sleeping associations whose members share large proportions of their home ranges. The functions of these sleeping associations have previously been hypothesised in a reproductive context. The genetic composition of these associations within a population of 162 (101,61) free-living individuals in Ampijoroa, north-west Madagascar, was analysed with 8 microsatellite markers in order to test predictions derived from kin selection theory. Socio-spatial structures were defined on the basis of capture and telemetric data that were collected over a total of 13 months distributed over three consecutive years. Female groups mainly consisted of one or more closely related dyads. Females that slept alone did not have close female kin in the vicinity or within the population at all, suggesting a matrilinear grouping pattern as a basic principle within this dispersed society. Within all three years, closely related male dyads lived larger distances away from each other than closely female dyads. Male-female dyads showed intermediate proximity values. These data support the hypothesis of female philopatry and male natal dispersal. This is the first genetic evidence of sex-biased dispersal for a dispersed nocturnal primate.

Are evictions of female helpers of cotton-top tamarin (Saguinus oedipus) related to contribution to infant carrying?

Susana Sánchez, Fernando Peláez, Carlos Gil-Bürmann
Psicobiología. Facultad de Psicología. UAM. Cantoblanco. 28049 Madrid. Spain. Phone: 34 91 397 87 48; Fax: 34 91 397 52 15
E-mail: susana.sanchez@uam.es

Carrying infants in cotton-top tamarins has been shown to be a costly activity and mothers benefit from being helped by other members of the group. Mothers frequently expel female helpers 2-3 months after birth, when infants are mostly independent. We observed five groups of cotton-top tamarins during 9 weeks after birth in the context of a carrying study. Shortly after the end of our observations, the eldest daughters were expelled from two large groups. We proposed that there might be a relation between evictions and a low previous contribution to infant carrying. However, contrary to this suggestions, a positive correlation was found between contribution to infant carrying by female helpers and aggression received from the mothers (rs=0.64 n=11 p=0.03). Furthermore, evicted females were those eldest daughters with the highest frequencies of infant carrying. While carrying, female helpers are less frequently attacked by male helpers (Wilcoxon, T=0.00, n=11, p=0.007), by other female helpers (Wilcoxon, T=0.00, n=11, p=0.005), and by mothers too (Wilcoxon, T=0.00, n=11, p=0.06). Therefore, a low contribution of female helpers to carrying does not seem related to their posterior eviction, although they might be using carrying in order to avoid aggression.

Financial support comes from Proyectos del Programa de Salud (08.7/0007/1998) and DGES (PB98-0094).

Male resource-defence monogamy in a nocturnal lemur?

Oliver Schülke
Department of Ethology and Ethology, German Primate Center, Kellnerweg 4, 37077 Göttingen
E-mail: oschuel@www.dpz.gwdg.de

Instead of living solitarily like most nocturnal mammals, nocturnal lemurs often live in pairs. Charles-Dominique and Petter (1980) described Phaner furcifer as pairliving and proposed 1) a monogamous mating system and 2) resource-defense by males to be the mechanism responsible for the formation of pairs. From sexual selection theory it is predicted that a monogamous species will exhibit small relative testis size and lack sexual dimorphism in body and canine size. If resource defense is a male service a) males should defeat conspecifics of either sex during territorial conflicts and b) females should be responsible for the maintenance of the pairbond, measured as frequency of approaches towards their partner. A total of 26 individuals of Phaner furcifer were captured and 14 animals radiotagged and observed (>840hours) from 6/99-6/00 in Kirindy, West-Madagascar. Relative testis size was small and sexual dimorphism was reversed in body mass and absent in canine size. During territorial conflicts males fought with males and females, but always lost against females. The frequency of approaches to the pairpartner did not differ between the sexes. Hence, morphological traits met the predictions for monogamous species. However, males were unable to defend their territory against females and therefore resource-defense can no longer be regarded as the evolutionary cause of pairliving in P. furcifer.

Dominance rank influences adolescent development in male mandrills (Mandrillus sphinx)

Joanna M. Setchell
Sub-Department of Animal Behaviour, University of Cambridge and School of Life Sciences, University of Surrey Roehampton
E-mail: j.setchell@roehampton.ac.uk

Previous research on semifree-ranging mandrills (Mandrillus sphinx) has shown that the degree of secondary sexual development differs between adult males. Whilst some males are brightly coloured, with large testes and high levels of plasma testosterone, and are associated with the social group of females and their offspring; other males are solitary, and lack fully developed secondary sexual features. In order to understand how such individual differences arise I studied development from puberty to adulthood in 13 males living as members of the semifree-ranging colony at the Centre International de Recherche Medicale, Franceville, Gabon. On average, testicular enlargement occurred at 5.5 yrs. Secondary sexual development began at 6 yrs, and males became more peripheral to the social group. By 8 yrs males were rarely observed with the group. Males reached adulthood at 9 yrs, at which age they could re-enter the social group and attain alpha rank. Great variation in development occurred between same age males, and this was related to dominance rank. Higher ranking males had larger testes, higher testosterone levels, and more developed secondary sexual characteristics for their age than lower ranking males. This rank-related variation continued into adulthood, resulting in the differences between “fatted” and “non-fatted” adult males previously described.

The use of tokens by chimpanzees

Cláudia Sousa and Tetsuro Matsuzawa
Primate Research Institute, Kyoto University, Japan
E-mail: sousa@pri.kyoto-u.ac.jp

Hominoids, that is humans and the great apes, use a variety of tools in contrast to other living primates such as monkeys and lemurs. However, while the nature of chimpanzee tool use is characterised by a one-to-one-correspondence between any particular tool and its target item, humans have developed a unique tool referred to as a "token". We define a token as an object that may be used for various goals and has a symbolic relationship to the target. We ran a series of experiments with the purpose of analysing both the reward and the tool aspect of tokens in chimpanzees. The results demonstrated that the chimpanzees were able to maintain performance in a variety of different tasks with tokens as the reward, and that this extended even to the acquisition of a new task. Our experiments also allowed the emergence of a new and very unique behaviour: chimpanzees spontaneously saved tokens before exchanging them for food. They were also able to use them as tools to be exchanged for their preferred food items in various choice contexts. The use of tokens thus provided a sensitive scale of preference for food items in chimpanzees.

Ontogeny of behaviour in captive orangutans

Marina A. Vancatova
Charles University, Prague, Czech Republic
E-mail: Vaclav.Vancata@pedf.cuni.cz

We studied the ontogeny of locomotion and behaviour of orangutans in Dvur Kralove Zoo, Czech Republic and Chester Zoo, UK. The frequency of locomotor behaviours is roughly equal during infant and juvenile phases and they form the third most frequent behavioural type. Terrestrial and arboreal locomotor behaviours occur more or less equally in the infant phase. However, the incidence of arboreal locomotion is three times higher in juvenile phase. The frequency of locomotor behaviour increases greatly in adult individuals where it is the most frequent type of behaviour. Feeding behaviour is less frequent during infancy. It increases during the juvenile phase and it is most frequent in adult individuals. This is related to an increase in the proportion of hard foods. Social behaviour is very rare in infants who spend most of their time in contact with their mothers. An increase in social behaviour was observed in juveniles, including an increase in the number of contacts with individuals other than mothers and fathers. Social behaviours are most frequent in adults. The incidence of social behaviour is twice as high in males compared with females. Play behaviour is frequent during the infant and juvenile phases, when it is the most frequent type of behaviour. Aggressive behaviour in all animals made up less than 1% of all behaviours.

Comparative study of growth in Macaca mulatta

V. Van_ata, A. Van_atová, V. P_ívratsk_, H. Zlámalová, V.G. Chalyan, N. Meishvili, I. Mazura
Department of Biology, Faculty of Education, Charles University in Prague, Czech Republic
E-mail: Vaclav.Vancata@pedf.cuni.cz

This comparative study includes more than 170 longitudinal studies of Macaca mulatta individuals from Konárovice, Czech Republic and 50 semi-longitudinally studied individuals from Sochi, Russia. Forty-eight somatometric traits were measured repeatedly from the birth to adulthood. Associated cross-sectional data include 980 additional records of body mass for the Konárovice macaques and 2185 records of body mass for more than 600 individuals from Sochi. Comparative analysis of growth patterns of macaques from Konárovice and Sochi shows that important ontogenetic events are accelerated by about one year in the Konárovice macaques. This difference in patterns can also be seen in the changes in body mass for the two groups, but the data for other body parameters can only be compared for discrete age categories. The pilot comparative study shows that similar growth patterns and growth velocities occur for at least some of the other body parameters such as body length, and limb length and circumferences. Macaques from Sochi are generally more robust with shorter total body lengths, relatively shorter trunks and relatively longer limbs.

Effects of environmental enrichment on care-giving and infant development in marmosets

Raffaella Ventura1, Hannah M. Buchanan-Smith1 and K. Morris2
1Scottish Primate Research Group, Department of Psychology, University of Stirling, Stirling, FK9 4LA, Scotland
2MRC Reproductive Biology Unit, Centre for Reproductive Biology, 37 Chalmers Street, Edinburgh, EH3 9ET, Scotland
E-mail: raffaella.ventura@tiscalinet.it

Early social environments have been widely recognised to have a long-term impact on primate well-being, but few studies have focused on the physical environment and the opportunities it offers. This study compared infant development and group care-giving behaviour in laboratory marmosets (Callithrix jacchus) in enriched and non-enriched environments. Twin infants from eight family groups were observed for the first 10 weeks of life. Non-enriched enclosures contained a nest box and branches. Enriched enclosures also had an artificial gum tree to stimulate the marmosets natural exudate gouging behaviour, wooden shelves to provide extra substrates, and a hanging screen to divide the enclosure visually and for the animals to swing from. In addition, a different novel object was placed in the enriched enclosure each week. Care-giving behaviour was not significantly different between the two conditions. However, infants in enriched enclosures performed several behaviours (e.g. scent-marking and self-grooming) significantly earlier than in the non-enriched groups, and they also played, explored and chewed wood significantly more. Other group members in the enriched groups also engaged in these behaviours significantly more. These results show that the environment affects both adult behaviour and infant development and plays an important role in establishing appropriate social and physical skills.

Morphological disparity of lemurs' skull investigated by Procrustes methods: environmental constraints versus phylogeny

Bénédicte Viguier
UMR CNRS 5561 ‘Biogéosciences’, 6 Boulevard Gabriel, F-21000 Dijon, France
E-mail: Benedicte.Viguier@u-bourgogne.fr

We compare skulls belonging to Lemur catta and the 5 species of the genus Eulemur (E. mongoz, E. macaco, E. coronatus, E. rubriventer and E. fulvus). This work uses geometrical morphometric methods: cranial morphology is analysed by landmark identification and Procrustes superimposition. These methods allow the description of pure shape difference, without any size effect, and the quantification of the differences between specimens. The geographical distributions of L. catta and the species of the genus Eulemur, less E. fulvus, are juxtaposed forming a continuum around most of the periphery of Madagascar. A similar situation is observed for the various subspecies of E. fulvus. For L. catta and the four species of Eulemur, or for the subspecies of E. fulvus, there is no strict concordance between geographical distributions and environmental zones. Nevertheless, morphometrical analyses show a correlation between the distribution of the taxa in morphological space and their geographical distribution. As a consequence of a high rate of homoplasy, phyletic relationships within the family are highly debated: various cladograms are found in literature. These cladograms are compared with a morphological distance tree computed here in order to determine if cranial morphology is more dependent on environmental factors or on phylogenetic

Exploration and consumption of novel and familiar food items by captive common marmosets

M.E. Yamamoto, F.A. Lopes, T.S. Leite and S.D. Azevêdo
Dept. of Physiology, Universidade Federal do Rio Grande do Norte, RN, Brazil
E-mail: eyamamot@uol.com.br

Common marmosets are omnivorous primates that present a highly diversified diet in the wild. In captivity they easily get used to novel food, but there are some reports suggesting that males and females respond differently to novelty. This study assessed the consumption of novel and known food items in 36 captive Callithrix jacchus (18 males and 18 females) from the UFRN colony, 14 born in the colony and 22 wild born. We presented 20 novel and 7 familiar food items to the animals and measured exploration (touching, sniffing and licking) and consumption of each item. The animals were alone when tested to avoid competition and the food was available for 10 min before the morning meal. Results showed that captive born animals explored the novel items significantly more than wild born animals and consumed the novel food significantly less. For all animals, novel food items were significantly more explored than familiar ones and significantly less eaten. There were no significant differences between males and females. Food availability in wild and captive environments and opportunities for exposure to novel foods in both situations are discussed as possible influences on the behavioural differences between wild and captive born animals.

Differential infant care in captive common marmosets (Callithrix jacchus)

M.E. Yamamoto, B.G.A.C.L. Santos and N.A. Lopes
Dept. of Physiology, Universidade Federal do Rio Grande do Norte, RN, Brazil
E-mail: eyamamoto@uol.com.br

Callitrichids provide communal infant care to twin offspring of the same or of different sexes. These primates lack sexual dimorphism, and only a few studies have examined behavioural gender differences among them. None of these studies has focused on parental care. The purpose of this study was to investigate gender differences in carrying behaviour in captive common marmosets. Sixteen twin infant pairs (6 male/female-MF; 3 female/female-FF; 7 male/male-MM) from the UFRN colony were followed during the first 8 weeks of infants’ lives. We registered the duration of infant carrying by all group members during 3 hours every week for each infant. Results did not show significant differences between total carrying time for each infant pair category (males from MF and MM pairs and females from MF and FF pairs) although FF were more carried than any other kind of pair. Fathers carried significantly more FF pairs and mothers carried more same sex pairs in comparison to different sex pairs. These results suggest that fathers invest more in daughters than mothers which could be related to different reproductive potential of the sexes in Callithrix jacchus, and possibly to future breeding competition between females.

Cross-sex bonding, reconciliation and consolation in hamadryas baboons (Papio hamadryas hamadryas)

F. Zaragoza and F. Colmenares
Dpto. Psicobiología, Fac. Psicología. Univ. Complutense de Madrid, Campus de Somosaguas, 28223. Madrid, Spain
E-mail: pspscy4@sis.ucm.es

In his description of the social structure of the harems of the hamadryas baboon (Papio hamadryas hamadryas), Kummer (1968) reported that the pattern observed in the frequency and directionality of affiliative interactions between harem females and their leader male and among harem females resembled a star (the “star-shaped” sociogram). Later studies have demonstrated that cross-sex bonding is a widespread characteristic of baboons, notably developed in the hamadryas species. So far, however, the test of the hamadryas’ star-shaped sociogram of affiliative interactions has been based on the analysis of grooming interactions. In this paper we lend further empirical support to Kummer’s hypothesis that cross-sex bonding is much stronger than female bonding by demonstrating that reconciliation and consolation tend to occur significantly more often between the harem male and his females than between the harem females themselves. Using focal sampling, data on the behaviour of adult antagonists during 10-min postconflict (PC) periods and during 10-min matched control (MC) intervals were obtained. 790 PC/MC samples were analysed for reconciliation, 391 for victim-initiated consolation and 361 for aggressor-initiated consolation. Reconciliation rates were higher between harem females and their harem male than among harem females (50% vs. 13%). Consolation tended to occur between harem females and their harem male but did not occur among harem females. These findings strongly suggest that in hamadryas baboons male-female relationships are highly valuable for both of them.