African Great Apes - Evolution, Diversity, and Conservation -

Abstracts for Oral Session

Nishida/Oral 1

Introduction: The Great Apes Symposium

Toshisada Nishida

Kyoto University, Japan

As one of the 21st century program that continues for 5 years, School of Biological Science, Primate Research Institute, and Center for Ecological Research, Kyoto University, initiated the "Formation of a Strategic Base for the Multidisciplinary Biodiversity Study" in 2002. This project aims to promote world-class research by unifying field research with new developments in molecular biology, to construct a basic academic discipline of "Biodiversity Science", and implement postgraduate education under a unified system of macroscopic and microscopic biology. Since the last century we have noticed the serious problem to be called as Biodiversity Peril. Biodiversity has disappeared quickly and ecological interaction networks have been deteriorated, in particular in such fragile ecosystems as tropical rain forests, coral reefs, marsh and lakes. These changes have had serious damages to human economical and cultural systems via deterioration of ecosystem function such as CO2 absorption and water purification. The reason why we need biodiversity is because our brain seeks biodiversity. A diversified environment is where our big brain evolved. In order for our brain to work actively, it needs a variety of environments and environmental stimuli such as forest, woodlands, savannas, mountains, hills, swamps, rivers and oceans, where there are many species of living things such as fungi, birches, bees, cichlid fish, frogs, hornbills, and snakes. More practically, our descendants will be as curious as ourselves; they will need places to explore, birds to watch, flowers to sniff, clams to taste, and the murmur of a stream to listen to. Our university successors need insects to collect, birds to count, seeds to experiment with, and trees to measure. More subjectively, I feel there would be neither pleasure nor joy for us if the only survivors were a few useful species such as livestock, pets, and garden plants in a ravaged earth environment. The most serious problem is that if there were only a few species of living things, society would not need us biologists! Thus, we clearly have a vested interest in conserving biodiversity. As this year's focal point, we have selected tropical forests and African great apes. I wish twenty two experts from all over the world will discuss earnestly the evolution of great apes, their role as the regenerator of the forests, diversity of great ape behavior, and their conservation. We will declare the establishment of GRASP-Japan and beg cooperation from all the participants and other people for the conservation of our nearest cousins.

McGrew/Oral 2

Compare and Contrast : Cultural Primatology and the Cultures of Primatology, in the Chimpanzees of Mahale and Gombe, Tanzania

W.C. McGrew

Depts. of Anthropology and Zoology, Miami University, Oxford, Ohio, U.S.A.

As the two oldest field studies of wild chimpanzees, Gombe and Mahale have much in common but also differ notably on several fronts. This partial overlap can be informative, both about the results of research and about the means by which research gets done. Both populations of apes are keen hunters of colobus monkeys and fishers of social insects, but they differ on other aspects of faunivory. Both have male coalitions that defend resources, but who compete differently among themselves. In both populations females immigrate, but patterns of female emigration differ. And so on. Both studies started with provisioning and then abandoned it, but in different ways. Both use focal subject sampling, but on different schedules. Both focus more on ethology than ecology, but emphasise different variables. And so on. Much of what we know about behavioural variation in the species comes from this matched pair of populations of Pan troglodytes schweinfurthii living on the eastern shore of Lake Tanganyika. Much of how we come to know what we know was devised there too. Unabashed scrutiny in a longterm context can be revealing and useful

Mitani/Oral 3

Demographic Influences on the Behavior of Chimpanzees: Lessons from Ngogo

John C. Mitani

Michigan University, U.S.A.

Recent research has revealed substantial diversity in the behavior of wild chimpanzees. Understanding the sources of this variation has become a central focus of investigation. While genetic, ecological, and cultural factors are often invoked to explain behavioral variation in chimpanzees, the demographic context is sometimes overlooked as a contributing factor. Observations of chimpanzees at Ngogo, Kibale National Park, Uganda, reveal that the size and structure of the unit group or community can both facilitate and constrain the manifestation of behavior.

Since 1995 David Watts and I have maintained continuous observations of the Ngogo chimpanzees. With over 70 adult males and females and approximately 150 individuals, this community is much larger than others that have been studied in the wild. We have taken advantage of the unusual demographic structure of this community to document new and intriguing patterns of chimpanzee behavior. Research to date has provided novel findings with respect to hunting, territoriality, mating, and male social relationships. Given the unusually large size of the community, chimpanzees at Ngogo hunt often and with a considerable degree of success. In addition, male chimpanzees there frequently patrol the boundary of their territory, engage in repeated bouts of lethal intergroup aggression, and adopt novel coalitionary mating tactics. By forming two distinct subgroups, male chimpanzees at Ngogo also develop social bonds above the level of dyadic pairs. While the sheer number of chimpanzees contributes to differences in hunting, patrolling, mating, and subgrouping at Ngogo, the demographic situation may also constrain behavioral interactions. At Ngogo, male chimpanzees who are closely related genetically through the maternal line do not appear to affiliate or cooperate with each other. Demographic constraints are likely to be responsible for this surprising finding. In my talk, I will use these examples to illustrate how the demographic context affects the possible range of behavioral options open to individuals and ultimately contributes to the explanation of behavioral diversity in chimpanzees.

Nakamura/Oral 4

Another Side of Culture: Beyond Humanlike Complexities

Michio Nakamura

Japan Monkey Centre, Japan

Compared to detailed studies of tool use in wild chimpanzees, social customs or cultural differences in the domain of sociality are relatively less understood. Recent efforts by our research team, led by Toshisada Nishida, have revealed that there are far more subtle behavioral variations unnoticed or unreported especially in this domain than we had thought. I will introduce some recent findings of such subtle cultural variations. Unlike various types of tool use, none of these subtle cultural behaviors seem to require so complex skills or intellectual processes and sometimes it is difficult to reason these variations in terms of their functions. This, in turn, might mean that researchers are more susceptible to complex, sophisticated, and perhaps useful humanlike behaviors than vague and casual behaviors which chimpanzees perform in their everyday life. For understanding such side of culture, I will reconsider the concept of ‘kaluchua’ by Kinji Imanishi in 1950s. ‘Kaluchua’ is an adopted word from English term ‘culture’. He used this instead of the word ‘bunka’, the Japanese equivalent to ‘culture’. For Imanishi, kaluchua was something like a ‘way of life’ shared by the members of a society, not because of genetic resemblance but because of social life, and was free from strong connotation that the term ‘culture (bunka)’ used to have. However, this connotation that culture must include somehow sophisticated, intentional, intellectual and complex humanlike aspects still seems to exist. For example, those who draw a distinct line between human culture and animal tradition by defining culture with complex and intentional learning mechanisms may tacitly bear such humanlike complexities in mind. In technological side of culture, we may have come far from our sister species, but our culture, and their culture also, is not only constituted of technology. In another side of culture, can we say that we are really more complex, intellectual or rational than chimpanzees? I want to discuss the importance of understanding animal culture beyond humanlike complexities.

Matsuzawa/Oral 5

Prerequisites of Cultural Transmission in Chimpanzees

Tetsuro Matsuzawa

PRI, Kyoto University, Japan

Recent field studies revealed that wild chimpanzees exhibited cultural differences in the cognitive skills. Chimpanzees at Bossou, Guinea, manufacture and use various kinds of tools unique to this community. The question is how the set of skills in one generation can be transmitted to the next generation? What kind of education is involved? We have carried out the long-term observation with video recording of tool-using behavior such as nut cracking since 1988. Chimpanzees use a pair of stones as hammer and anvil to crack open oil palm nuts. We found that it took about 9-10 years to reach to the refined level of adults and there seems to be a critical period for learning between the ages of 3.5 to 5 year old. The age of acquiring this nut-cracking skill is a little higher than the other kinds of tool use such as using leaves for drinking water that could be acquired at the age of two. Analysis of stone and nut combinatorial behavior reveals distinc stages of cognitive development that are irreversible and comparable to those of human children. The study has revealed the chimpanzees' way of education, what I called "Education by master-apprenticeship". The way is characterized by the following three points. First, mothers take the role of models, but they do not do any active teaching. Second, there is a sort of intrinsic and strong motivation of the infants to make the copy of the behaviors of the mothers. Third, the mothers show high level of tolerance toward the infants. The mechanism of observational learning in chimpanzees is based on the long-term mother infant bond. Understanding chimpanzees illuminates the human-unique characteristics in education, such as social reference from infants and social praise by the mothers.

Yamagiwa/Oral 6

Foraging Strategies of Gorillas and Chimpanzees in the Sympatric Habitats : Hints for Socioecological Features of Early Hominid

Juichi Yamagiwa

Kyoto University, Japan

Kanyunyi Basabose

Centre de Recherche en Sciences Naturelles (DRC), Democratic Republic of Congo

Sympatry of different ape genera may provide us useful hints for considering sympatry of proto-hominid genera and species in later Miocene and Pleistocene. Based on 8-year field studies in the Kahuzi-Biega National Park, Democratic Republic of Congo, We compare foraging strategies of gorillas (Gorilla beringei graueri) and chimpanzees (Pan troglodytes schweinfurthii) that coexist sympatrically. Dietary compositions of gorillas and chimpanzees show remarkable similarities, especially during the dry season. Gorillas and chimpanzees ate 21 and 25 species of fruits, respectively. Chimpanzees also preferred the fruit species preferred by gorillas. Monthly fruit index calculated from total basal area per ha and the proportion of the number of trees in fruit for each species shows a larger fluctuation in the abundance of fruits eaten by chimpanzees than that by gorillas. Fruit species preferred only by chimpanzees showed a distinct intra-specific synchrony in fruiting, while fruit species preferred by gorillas and chimpanzees did not. These differences in fruiting patterns may influence the foraging patterns of gorillas and chimpanzees. Gorillas tended to travel widely in a cohesive group and to increase their consumption of fruits in the primary forest during the dry season. By contrast, chimpanzees tended to continuously visit particular fruiting trees individually in a small home range throughout the entire year. Chimpanzees tended to avoid nesting in trees bearing fruits preferred by gorillas. These observations imply niche separation between gorillas and chimpanzees. Some tree species that have large basal areas and that bear fruits for a long period may be able to support the survival and sympatry of gorillas and chimpanzees. Proto-hominids may have experienced sympatry with other hominoids, and niche separation may have promoted human-specific foraging strategies using bipedal walking.

Stanford/Oral 7

The Sympatric Ecology of Great Apes ; Implications for the Evolution of the Hominid Diet

Craig Stanford

Departments of Anthropology (Chair) and Biological Sciences

Jane Goodall Research Center, U.S.A.

The behavioral ecology of great apes in sympatry may reveal aspects of the evolutionary forces shaping their social systems, as well as important information about the ecology of extinct sympatric hominoids. The Bwindi Impenetrable Great Ape Project is an ongoing 7 year study of chimpanzees (Pan troglodytes schweinfurthii) and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda. We found that the two species had similar diets. Bwindi gorilla diet was overall more folivorous than chimpanzee diet, but was markedly more frugivorous from that of gorillas in the nearby Virunga Volcanoes.?During four months of the year Bwindi gorilla diet included more food species than that of the chimpanzees did. Three factors in particular - seasonal consumption of fibrous foods by gorillas, interspecific differences in preferred fruit species, and meat consumption by chimpanzees - contributed to dietary divergence between the two species. We have observed four encounters between Bwindi chimpanzees and gorillas. Three of these took place in Ficus sp. and were nonaggressive; one took place in a fruiting Chrysophyllum sp. tree and was aggressive. A party of chimpanzees controlled the tree crown for an hour, displaying at a gorilla group that attempted to enter the tree. We conclude that contest competition for food exists between chimpanzees and gorillas, although whether such occasional contests of ecologically important to either species is unknown.

Remis/Oral 8

Ecological Adaptation of Western Lowland Gorillas : Behavioral, Morphological and Nutritional Aspects of Gorilla Diet and Niche Separation from Sympatric Chimpanzees

Melissa J., Remis

Department of Sociology and Anthropology, Purdue University, U.S.A.

Recent research on gorillas has highlighted the importance of fruit consumption and dietary flexibility among most gorillas, ecological variation among populations appears related to altitude and resource availability. TraTraditional characterizations of gorillas as folivores have now shifted to include seasonal frugivory at all but the highest elevation sites. Lowland habitats contain higher diversity of fruit and nonfruit foods for gorillas and sympatric chimpanzees and apes in these habits consume a wide variety of fleshy, sugary foods. Nevertheless when ripe fleshy fruit is not plentiful, gorillas consume varying amounts of fibrous fruits and foliage, in contrast to the more persistent fruit eaters, the chimpanzees. Thus, debate continues on the nature of gorilla dietary adaptation and how to differentiate it from the more frugivorous chimpanzee. This paper will examine the consequences of large body size and anatomy for dietary flexibility among gorillas across habitats and the consequences of variation in fruit and nutrient intake relative to sympatric chimpanzees. Field research from lowland Bai Hokou field site in the Central African Republic will be integrated with experimental studies of digestion, taste and food preferences among captive apes in a zoological setting. The evolutionary implications of variations along a continuum of dietary adaptations to frugivory amon the African apes will be discussed.

Huffman/Oral 9

The Chimpanzees of Rubondo Island- Repatriation to Africa and the Adaptation of West African Chimpanzees to an East Africa Environment

Michael A. Huffman

PRI, Kyoto University, Japan

A bold attempt to 'repatriate' 17 wild born west African chimpanzees to East Africa was made between 1966-1969 by the Frankfurt Zoological Society (FZS). This is the first and currently only example of a long-term viable and self-sustaining released chimpanzee population. The site selected for this release was Rubondo Island, later gazetted in 1977 as a National Park. The island is located in southwestern Lake Victoria, Tanzania. The chimpanzees originally came from various west African countries before they were taken to European zoos. They were released onto Rubondo island at four different times during the 3 year period. Outside the know range of chimpanzees, over 90% of the 240 km2 island is made up of mixed evergreen and deciduous forest, dominated by Croton sylvaticus, Diospyros mespiliformis and Synsepalum brevipes. The understory is dominated by Pancovia turbinata and Crateraspermum schweinfurthii. Lianas containing preferred chimpanzee foods such as Saba comorensis, Strychnos lucens and Uvaria spps. are found throughout much of the forest. The release was overseen by FZS, but without any subsequent monitoring or provisioning on the island until 1996. Since then, FZS and Tanzania National Parks have provided monetary, logistical and personnel support for chimpanzee habituation. From 2000, with partial support from TANAPA and FZS, the author has been coordinating the efforts of an international research team to further habituate and conduct ecological and socio-behavioral research on these chimpanzees. Currently, the population is estimated to have increased to approximately 40 individuals. Daily sitting records strongly suggest that they are organized into 2-3 stable mixed groups with two other males always traveling alone. The increase in the number of chimpanzees since their reintroduction and the presence of several infants and juveniles demonstrates that they have successfully adapted to the ecological conditions of the island. Habituation will need to proceed before details of the assumed independent groups' social organization and intergroup interactions can be fully elucidated, but current data suggests that these different groups lack independent territories, instead avoid one another while routinely ranging across the island from north to south to forage. Meat eating, insect eating and tool use in the form of ant fishing have been verified. With the aid of GPS, GIS, development of advanced bio-molecular techniques for genetic and health analysis on site, parasitology, standard ecological and meteorological monitoring, this long-term research initiative aims to fully assess the level of adaptation by this introduced population into a novel environment.

Hunt/Oral 10

Chimpanzee Socioecology in a Hot, Dry Habitat : Implications for Early Hominin Evolution

Kevin D. Hunt

Department of Anthropology Student Building 130, U.S.A.

Since July of 1996 my team and I have studied chimpanzee socioecology and ecomorphology at the Toro-Semliki Wildlife Reserve, Uganda. We have established 20 phenology transects, and we have climate data dating back to 1998. Rainfall for 1998-2002 has average 1452 mm (1107-1767), compared to 1714 mm at Gombe, 1570 mm at Kibale, 1842 mm at Budongo, 1762 mm at Mahale, and 954 mm at Mt. Assirik. The mean minimum daily temperature hovers around 20°C, and the daily maximum averages 34°C. Relative humidity daily maxima are above 90%, even in the dry season. Habituation has been slow. Hunt and McGrew (2002) have speculated that the challenges of habituating wide-ranging, dry-habitat chimpanzees are different than for moist-habitat populations. The cautious and wary nature of chimpanzees makes them anxious subjects in open habitats, regardless of whether they are on the ground or in trees, and slows habituation. We have searched for chimps 1,619 days, locating them 951 times. Based on direct observations and our dung-washing program, Semliki chimpanzees have a very limited food list of only 43 food-items, including unidentified items, compared to 300+ at Mahale. Direct observation and dung straining have yielded evidence of only four hunting bouts over 7 years. Chimpanzees at Semliki range over areas much larger than most other chimpanzees. The minimum convex polygon area for all sightings of individuals believed to be in the Mugiri community is 50.1 km.2. This exceeds the home-range size of all known, habituated communities other than Mt. Assirik. Feeding parties are large, averaging nearly 5 individuals. The present state of poor habituation suggests these numbers likely an underestimate. This is surprising, since Semliki chimpanzees emit noticeable fewer vocalizations than do other chimpanzees. Party size was smaller in the wet season, but not significantly. The daytime party mean of 4.8 at Semliki is consistent with data collected on 348 overnight nests. Nests were found in groups averaging 5.0 members (±3.23, N=348, maximum=12), larger numbers than those found in most other communities. As models for early hominid evolution, Hunt and McGrew (2002) note that few observations at Semliki conform to models that link human attributes to adaptation to dry habitats. The suspicion that dry-habitat chimpanzees might be more terrestrial than forest chimpanzees is not supported at Semliki. The Semliki toolkit is limited so far to sponges, suggesting that dry-habitat apes use tools no more intensively than other apes, and may use tools less. Dry habitat chimpanzees have not been seen to use underground storage organs, they hunt little, and show less evidence of inter- and intracommunity aggression than other populations. As expected by a Postural Feeding hypothesis for the evolution of bipedalism, anecdotal observations suggest that dry-habitat chimpanzees are more bipedal than other chimpanzees, in particular when harvesting fruits from the abundant Grewia and Securinega bushes found at Semliki.

Anderson/Oral 11

Chimpanzee Movement Patterns and Social Ecology in the Taï National Park, Côte d’Ivoire

Dean P. Anderson

Department of Zoology, University of Wisconsin-Madison, U.S.A.

Julia Lehmann

Max Planck Institute for Evolutionary Anthropology, Germany

Christophe Boesch

Centre Suisse de Recherche Scientifique, Côte d’Ivoire

Chimpanzee mental maps of habitats should allow them to choose direct paths between food sources. However, daily paths are often very sinuous. The movements of individuals are the foundation of grouping patterns in social groups, therefore it is important to understand the factors that influence movement decisions. The abundance and distribution of food fluctuates seasonally, and chimpanzee movement patterns are expected to adapt to such changes. We analyze three years of data from the Taï National Park, Côte d’Ivoire to address two inter-related questions. One, is the relative sinuosity of daily movement paths of chimpanzees influenced by the abundance and distribution of food, the gender or reproductive status of the individual, or the presence of estrous females in the social community? Direct paths are expected between large but widely separated food patches; whereas more sinuous paths are expected when food is found in small and uniformly distributed patches. However, movement patterns may be affected by the reproductive status of the individual or by the presence of estrous females in the community. Males may exhibit more direct daily paths, as they are more frequently involved in territorial defense than females. Two, is there a relationship between party size and the sinuosity of daily paths? Large parties have an increased number of individuals that could potentially influence movement decisions, which may result in more sinuous movement patterns. Alternatively, the increased foraging competition experienced by large parties may result in direct paths between food patches. We quantify movement sinuosity by examining the distribution of turning angles of daily paths, and by calculating the ratio of net daily displacement to daily path length. Day-long-observation follows were conducted for adult males, non-estrous females, and estrous females. Monthly estimates of the abundance and spatial distribution of food were calculated from extensive data collection on the size, density, and phenology of food-producing trees. This analysis will examine factors that influence individual movement patterns, and unravel the interactions between movement, food availability, estrus, and social grouping.

de Waal/Oral 12

Similarities and Instructive Differences in the Social Organization of Wild and Captive Chimpanzees

Frans Waal

Yerkes Primate Center, Emory University, Atlanta, GA, U.S.A.

Chimpanzees in captivity often have provided a pre-view of the capacities to befound in the field, such as tool-use and reconciliation behavior. Apart from certain areas of behavior that cannot be studied in captivity, such as inter-group relations and hunting of large prey, this setting permits study of the details of behavior under controlled conditions. For example, at Living Links/Yerkes Primate Center we have had successful studies of facial kin recognition (Parr et al.), social reciprocity (de Waal), theory-of-mind (Hare et al.), reconciliation (Preuschoft et al.), audience effects (Brosnan & de Waal), prescriptive social rules (Flack et al.), and so on. Because of the obvious complementarity between captive and field research, it is important to ask in which ways captive social life differs from life in the field. The main difference, I feel, concerns the relation between the sexes, which is more egalitarian in captivity owing to a powerful female alliance that curbs male dominance. Male politics and dominance relations, on the other hand, seem similar in captivity and the field. The second major difference concerns the need for aggression-control and reconciliation in captivity. Such a need also exists in the field but is far less urgent. The fission-fusion nature of wild chimpanzee communities means that distancing following aggression is an option. Data indicate that reconciliation rates are higher in captivity. The mechanism of reconciliation is essentially the same in captivity and the field, however. In fact, all psychological mechanism found in the field exist in captivity, and vice versa. The difference is in the way and intensity with which they are being applied.

Wittig/Oral 13

Reconciliation and Cooperation in Chimpanzees (Pan troglodytes) - in Comparison with Species of the Genera Gorilla and Homo

Roman M. Wittig

Max-Planck Institute for Evolutionary Anthropology, Leipzig, Germany

Group living is associated with a number of advantages, such as increased protection against predators, better food acquisition and cooperative rearing of offspring. However, it also incurs disadvantages, as group living increases competition over food, mates and space. Therefore conflicts and aggression are more likely to occur and aggression disturbs the relationship between opponents. That group living animals compete with the same partners they usually cooperate with creates a dilemma, as an out-competed partner may withhold cooperation the next time. A solution to this dilemma is that social living animals, such as primates, develop ways to cope with conflicts and their consequences. One way to cope with social consequences of aggression is reconciliation. Reconciliation appears to repair the relationships of former opponents, which have been disturbed by aggressive interactions. Reconciliation seems to be the most beneficial option for cooperative partners, despite other possible options for coping with conflicts and their consequences. The incorporation of reconciliation in a species’ natural behavioural repertoire should be especially adaptive for those with complex cooperations. This would suggest that species that engage in more cooperative behaviours are also engaging in more reconciliation. Apes show a large inter-species variation in cooperation during food acquisition and during competitive situations. Pan species seem to be the most cooperative ones among the great apes. For example Pan troglodytes collaborates in hunting, develops long-term alliances and adopts children of ‘friends’ that died. The genus Homo, however, has probably evolved the most complex cooperations in the animal kingdom. I will present the pattern of reconciliation and cooperation for a community of wild Pan troglodytes in the Taï National Park, Côte d’Ivoire, and will investigate the relationship between reconciliation and cooperation. Moreover, I will compare those patterns of Pan troglodytes with data that are available for reconciliation and cooperation in species of the genera Gorilla and Homo.

Furuichi/Oral 14

Towards the Understanding of Behavioral Diversity among Bonobo Populations, and between Bonobos and Chimpanzees

Takeshi Furuichi

Faculty of International Studies, Meiji-Gakuin University, Japan

Though long disturbed by the civil war, study of wild bonobos has been resumed in many sites. Currently active study sites, including Wamba, Lomako, Salonga National Park, Lukuru, and Lac Tumba, cover various environments from the central part of rain forest to the patchy area of forest and grassland savanna. They provide us valuable information for the understanding of diversity of ecology and behaviors of bonobos, and between chimpanzees and bonobos. Recently Hohmann and Fruth made a preliminary analysis on the behavioral difference of bonobos between Lomako and Wamba. To expand such a comparison, researchers working in all the study sites met in a workshop held in Japan in July 2003, and compiled a comprehensive ethogram for bonobos, and collected information on the presence or absence of each behavior in each study site. Because this ethogram was made based on the Nishida’s ethogram on chimpanzees, it will also contribute to the comparison of behaviors between chimpanzees and bonobos. In this symposium, I will report some of the results of preliminary analysis of this ethogram. I will further discuss on the two major domains of behavioral differences between chimpanzees and bonobos, the sexual behaviors and tool-use behaviors.

Hashimoto/Oral 15

Comparison of Sexual Behaviors between Chimpanzees and Bonobos

Chie Hashimoto

PRI, Kyoto University, Japan

We compared copulation behavior between chimpanzees in the Kalinzu Forest, Uganda and bonobos in Wamba, DR. Congo. Female chimpanzees copulated much more frequently than female bonobos did during the maximal swelling period, as previous studies have revealed. We observed very promiscuous mating for the chimpanzees. Eight female chimpanzees copulated 2.7 times per hour on average (329 copulations in total; tentative analysis on observation until 2002). We also analyzed complete sequences of copulation using the same definition (32 copulation sequences for bonobos and 105 for chimpanzees) to examine the sexual attractiveness, receptivity, and proceptivity of females. While males initiated almost all copulation attempts in bonobos, only half of copulation attempts were initiated by males in chimpanzees. While males began to show approach or courtship at a longer distance than females did in bonobos, both males and females began to approach or show courtship behavior at a distance of more than 5m. This study suggests that female chimpanzees are more disposed to copulation than female bonobos are.

Wrangham/Oral 16

The Evolution and Devolution of Violence : How Pan Illuminates Homo

Richard W. Wrangham

Harvard University, U.S.A.

Current data suggest that chimpanzees and humans experience similar risks of violence in intergroup encounters, whereas in intragroup interactions rates of violence are much lower in humans. To explain why humans have relatively peaceful intragroup relationships I consider behavioral and skeletal similarities among bonobos, domesticated animals, and humans. Bonobo and human similarities are clearly not homologous. Instead, parallels in these three groups suggest that they have experienced analogous processes of domestication. In humans, the process is attributed to the evolution of communal sanctions, which most likely became increasingly powerful with the origins of anatomically modern humans.

Oates/Oral 17

Great Ape Conservation Challenges in the Gulf of Guinea Biodiversity Hotspot

John Oates

Hunter College, U.S.A.

I would explain the importance of the Nigeria-Cameroon border region as a biodiversity hotspot in Africa. This rain-forest region is a centre of endemism for many groups of plants and animals, including primates. Among the primates are two endemic ape subspecies: Gorilla gorilla diehli and Pan troglodytes vellerosus. I would discuss the conservation problems posed by a dense human population (along with a large commercial bushmeat trade), and the impact of local and international sociocultural and political factors.

Wakibara/Oral 18

Great Apes and Seed dipersal :Implications for Conservation

James V. Wakibara

Tanzania National Parks, P O Box 3134 ARUSHA, Tanzania

Ripe fruit is a major dietary component of most great apes, especially chimpanzees. They often swallow intact, a large amount of fruit of multiple species and subsequently either spit or defaecate seeds extensively kilometres away from source plants. The majority of seeds that they disseminate are often viable, at times with shortened germination latency. By virtue of their large sizes, great apes may also be particularly indispensable as dispersers of some large-seeded plant species in the environments in which they dwell. I explore the behavioral features of fruit foraging and seed handling by great apes, especially chimpanzees. It is considered that such features do facilitate the maintenance and heterogeneity and hence conservation of tropical forests.

Plumptre/Oral 19

Counting Apes for Conservation

Andrew J. Plumptre

Albertine Rift ProgrammeWildlife Conservation Society, U.S.A.

In order to conserve a species it is important to know where they occur and have some idea of how many there are. This information helps prioritise where conservation action should take place. There are currently a plethora of methods for surveying primate populations, some of which produce reasonable results and others which are flawed and yet still promoted. For instance the use of 'observer-animal' distances on line transect surveys to calculate the probability detection curve is a technique that has no mathematical basis and should not be used. Apes live at low densities wherever they occur in comparison with other primates and are far more difficult to census as a result. Yet Apes are all endangered and there is a critical need to determine population sizes and monitor them to determine whether conservation activities are helping them. Survey techniques for apes vary and examples will be given of the estimate of complete counts of mountain gorillas (Gorilla beringei beringei) from Bwindi Impenetrable National Park and standing crop and marked nest counts of chimpanzees (Pan troglodytes schweinfurthii) to estimate the population throughout Uganda.

Bermejo/Oral 20

Ebola and the decline of gorillas and chimpanzees in the Lossi Faunal Reserve , North Congo

Magdalena Bermejo

University of Barcelona, Spain

During a 8 year data collection period (1994-2001), high densities of gorillas Gorilla gorilla gorilla and chimpanzees Pan troglodytes troglodytes were found in the Odzala National park and the Lossi Reserve of faune in North Congo. Here we present survey results conservatively indicating that ape population in Lossi Reserve declined about 55% between 2000 and 2002. Over the past 18 months, wildlife conservation workers and an international research team have found many ape carcasses in Congo, across the border from 2001 human epidemic site at Mekambo. Since December 2002, the carcasses of seven gorillas from a study population at Lossi have been found, along with five chimpanzee carcasses. The study population originally included 143 individually identified gorillas, but after exhaustive searches only seven have been found alive. Recent data from nearby sites of the Lossi study population indicate that the epidemic was limited to the west of the Lebamou river. Research on modes of Ebola transmission chain should be investigated actively.

Ammann/Oral 21

Great Ape Conservation and the Bush Meat Crisis

Karl Ammann

Conservationist, Photographer, Kenya

The great apes clearly have the potential to be a key indicator species in evaluating the status of our natural world. If we can not find the resources and the political will to better protect our closest animal relatives then what hope can there be for some of the lesser species, the valuable trees making up a crucial part of the primary forest ecosystems, the marine resources in the oceans, etc.?

When looking at great ape conservation in this context then things do not look good. Tropical hard wood timber is probably the most luxurious of a wide range of natural resources extracted at a totally unsustainable level. The mechanized logging of the world's remaining primary forest impacts ape populations more, in the form of habitat loss and bush meat hunting, then any other factor.

However, past attempts to curtail logging in Asia, Central and West Africa, through consumer boycotts or the implementation of acceptable certification systems, have now taken a back seat to more pragmatic approaches. Such as trying to clean up after logging or attempting to reduce the illegal timber export, which in many of the countries in question exceeds legal exports. In this context the bar has pretty much been lowered to the ground, as far as great ape conservation is concerned. Steps taken, largely in form of pilot projects, amount to trying to cure a terminally ill cancer patient with band aids!

The time has come to rethink and frankly discuss the track record of the conservation community on whose watch the bush meat crisis and the 'logging mess' developed? Are we willing to learn from past and present mistakes, reevaluate our approach and options? Are we ready to accept that increased accountability and transparency, combined with independent hird party peer reviews are steps which need to be taken?

I have come to the conclusion that the policy makers and conservationists of the developed world are as much a part of the problem affecting the great apes as is the hunter in the forest who pulls the trigger.

Redmond/Oral 22

Can the United Nations Save the Great Apes?

Ian Redmond

Wildlife Consultant, Apes and Elephants

Head, GRASP Technical Support Team, UK

Most populations of great apes are declining alarmingly, and yet there probably isn’t a person on the planet who actively seeks to extirpate all gorillas, chimpanzees, bonobos or orangutans. Even those who profit by killing or capturing them presumably wish to continue doing so. No, the impending extinction of our closest living relatives is happening by accident rather than by design, which makes us – the whole of humanity – guilty of collective negligence. Despite the warnings by experts and increasingly detailed evidence to emerge in recent years, the world is only now waking up to the fact that significant steps need to be taken immediately if extinction is to be averted.

Given the importance of great apes on scientific, cultural and ethical grounds, their survival is of concern to all thinking people in every nation. It should not just be left to the 23 countries in which they are currently found, sixteen of which are listed by the United Nations as ‘Least Developed Countries’ with an annual per capita income of less than $800 per annum. What is needed is a global strategy and global responsibility – which is why GRASP – a UN initiative launched by UNEP and UNESCO – offers new hope.

GRASP is registered with the Commission on Sustainable Development, as a partnership between UN agencies, governments, NGOs and the private sector. Its goal is to bring together all those working for great ape survival in a unified global plan, comprising National Great Ape Survival Plans in all 23 range states, regional agreements between neighbouring range states, and integrating ape conservation into national biodiversity plans and poverty reduction strategies. Great apes are seen as great assets in Rwanda and Uganda for example, where carefully regulated ecotourism based on viewing gorillas and chimpanzees brings significant economic benefits to the government and to local communities. The question remains, can this positive attitude be applied elsewhere, and if so, can such development be regulated so that it contributes to ape conservation rather than adding further pressures on dwindling ape populations.

The United Nations has, through GRASP, taken on the task of saving the great apes. But if the international community fails to make the necessary resources available, there is little chance of success.

Nishida/Oral 23

Toward the Establishment of GRASP-Japan

Toshisada Nishida

Kyoto University, Japan

To save the great apes from extinction, United Nations Environment Program (UNEP) has implemented the Great Ape Survival Project (GRASP) since 2001. Japan is one of the countries where intensive and long-term ape research has been conducted by many researchers in the natural environment. Japanese research extends from Tanzania, Uganda, and DRC to Gabon, Congo, Cameroon, Guinea, and Indonesia. Japanese great ape researchers are founding the GRASP-Japan with conservation NGOs and other parties concerned. Our mission will be to strengthen ongoing Japanese great ape research and conservation projects, to conduct lobbying activities to the Japanese Government, to propose new JICA projects that are relevant for the conservation of great apes and to organize fund-raising activities, as well as to provide GRASP HQ with key local information and to promote the establishment of the "World Heritage Species" concept in cooperation with GAWHSP inc. (Great Apes World Heritage Species Project) lead by Richard Wrangham.