PSGB Spring Meeting 2005

Tuesday 22nd and Wednesday 23rd March
University College Chester, Chester UK

Paper Abstracts

Keynote Talk

Is Man a Wolf to Man? – Morality and the Social Behavior of our Fellow Primates

Frans B. M. de Waal

Frans de Waal giving the keynote talk at the PSGB Spring Meeting 2005.

Homo homini lupus – “man is a wolf to man” - is an old Roman proverb popularized by Thomas Hobbes. Even though it permeates large parts of law, economics, and political science, the proverb contains two major errors. First, it fails to do justice to canids, which are among the most gregarious and cooperative animals on the planet. But worse, the saying denies our own species’ thoroughly social nature.

For the past quarter century, the very same view has been promoted by an influential school of biology founded by Thomas Henry Huxley, which holds that we are born nasty and selfish. According to this school, it is only with the greatest possible effort that we can hope to become moral beings. This view of human nature is discussed here as “Veneer Theory,” meaning that it sees morality as a thin layer barely disguising less noble tendencies. Veneer Theory is contrasted with the position of Charles Darwin, who saw human morality as a natural outgrowth of the social instincts and as continuous with the sociality of other animals.

Veneer Theory is criticized at two levels. First, it suffers from major unanswered theoretical questions. Why would humans, and humans alone, have broken with their own biology, and how would such a feat be possible? Second, Veneer Theory is unsupported by empirical evidence. It would predict that morality resides in the most recently evolved parts of our enlarged brain, and that it leads to behavior that deviates from anything animals do. Both are verifiably wrong. Human moral decisions often stem from emotionally driven “gut” reactions, some of which we share with other animals. They may not be moral beings, but do show signs of empathy, reciprocity, and a sense of fairness that promote a mutually satisfactory modus vivendi. I will review evidence for continuity between humans and other primates to support the view that the building blocks of morality are older than our species.

Reproductive conflict and regulation of relationship in non-primates: lessons from meerkats

Nobuyuki Kutsukake

The need to regulate relationships is not restricted to primates but may be ubiquitous in group-living animals. Comparison between primates and non-primates may elucidate the uniqueness of primate social behaviour and selective forces for the evolution of relationship regulation within a group. I studied cooperatively breeding meerkats Suricata suricatta during one breeding season, and investigated how reproductive conflicts between females are reflected in social interactions and how the conflicts are resolved. In this species, dominant females produce >80% of litters but older subordinates (especially sisters or older daughters of the dominant female) occasionally breed. The older subordinate females received aggression from the dominant female more frequently than younger ones did, and were evicted from the group during the breeding season. Grooming by subordinates may function to placate the dominant female because subordinate females groomed the dominant female more frequently than vice versa. Also, grooming by the subordinate females increased as the birth of pups approached. Although the older subordinate females submitted most frequently to the dominant female, submission did not reduce the agonistic tendency of the dominant female. 'Reconciliation' was rarely observed after aggression. Subordinate females avoided the dominant female after aggression, which may be one of the conflict management strategies in this species. These findings suggest that social interaction reflected the reproductive conflict between females, and meerkats have limited number of behavioural options to regulate their relationships. This may be related to the strong reproductive skew seen in this species.

It takes a community to rear a chimpanzee, or does it?

William C. McGrew & Melanie M. Beuerlein

From the outset, studies of social relations in wild chimpanzees have been confused: some de-emphasize the group and focus on the minimal social unit of mother and dependent offspring (Goodall, 1968).  Others emphasise the collective nature of the unit-group or community (Nishida, 1968).  All agree on the fission-fusion nature of society in Pan troglodytes, but the differing implications for social development have been surprisingly ignored.  Here, we ask a simple question: who socializes chimpanzee youngsters?  We analyze focal-subject data on the social lives of five juveniles (unweaned 2-5 year-olds) at Gombe.  The results are surprising: most of the time youngsters are alone with their mothers.  Even when with others, they are in small parties.  Many group members are never encountered.  Maternal kin figure little.  Each youngster’s social circle is different; there are no individual, common socialisers, but there are age-sex differences in their companions.  Thus, it is not surprising that Gombe’s immature chimpanzees suffer high mortality, if orphaned, unless surrogate foster care is available.  Childhood socialization in chimpanzees depends on the mother.

Fission-fusion dynamics complicate the regulation of social relationships

Filippo Aureli & Colleen M. Schaffner

According to Kummer's functional perspective, social relationships can be viewed as potential investments depending on the benefits the partner can provide. Social interactions are then viewed as ways of maximising gain and minimising loss. Dyadic social relationships are also affected by the interactions with or simply by the presence of third parties. The resulting network of interactions makes the regulation of social relationships a highly demanding task. In species that live in groups experiencing frequent fission-fusion, such regulation could even be more complicated. In these species group members are rarely all together and form fluid subgroups that fission and fusion with different composition. Fission-fusion dynamics pose therefore problems for the negotiation of social relationships because partners may be out of contact for extended periods and relationships among other individuals may change while they are in different subgroups. Fusion events are likely to be particularly challenging. We could then expect individuals to possess enhanced abilities to extract information from subtle social cues and to exchange bond-testing behaviours at fusion. We tested such predictions using data from two wild groups of spider monkeys living in Otoch Ma'ax yetel Kooh nature reserve, Yucatan, Mexico. First, we found that fusions are periods characterised by tension as the rate of aggressive interactions between individuals fusing is higher than those when they had been in the same subgroup. Second, we found that, unlike grooming, risky intimate contacts such as embraces, pectoral sniff and' kisses' were exchanged more often at reunions than at baseline. Furthermore, we hypothesize that subtle social cues could be used to update knowledge of others' relationships via emotional mediation in a similar way to what we have previously suggested for the assessment of an individual's own social relationships. If so, the social experience gained at reunion may update the emotional summaries' not only of one's own social relationships, but also of the relationships between other group members­.

When Worlds Collide: Patterns of Engagement among Male and Female Baboons

Peter Henzi, Parry Clarke & Louise Barrett

The twin realities of marked sexual dimorphism and infanticide risk frame the arena in which adult baboons meet and interact. The infanticidal tendencies that enable males to maximise limited periods of reproductive opportunity come back to haunt them in the shape of depredations by other males on their own infants. Females are obviously opposed to infanticide from any quarter but their size constrains any direct attack on males, requiring them to respond indirectly to protect their interests. This structures interaction in ways that reveal the need by individuals of each sex to manage conflicting tactics in relation to current circumstances and the decisions of others. In this talk we review the relevant comparative information and outline a research programme with data from a long­term study of chacma baboons.

What Regulates Hvpothalamic Pituitary Adrenal Activity in Lion-tailed Macaques (Macaca silenus)?

Lindsay Skyner & Tessa Smith

It is essential that captive animals experience good welfare for ethical, educational, scientific and conservational reasons. Assays that measure faecal or urinary cortisol are useful non-invasive tools for quantifying welfare and in particular the effects of different variables on primate physiology (e.g. the effects of visitor numbers, group changes and enclosure parameters). High levels of cortisol could potentially suggest compromised welfare and may interfere with reproduction. This is especially important for endangered species such as lion-tailed macaques where captive breeding may be essential for species conservation.

There were two aims to the research. First we wanted to immunologically and biologically validate enzyme immunoassays (EIA) to detect cortisol in lion­tailed macaque urine and faeces. The second aim was to investigate any potential link between cortisol levels and (a) zoo visitor numbers (b) location in the enclosure and (c) behaviours likely to reflect welfare such as locomotion, aggression and grooming.

Focal animal behaviour data and faecal and urinary samples were collected from 7 lion tailed macaques (housed in one social group) over 16 weeks. EIAs to quantify faecal and urinary cortisol were successfully immunologically validated by demonstrating accuracy, precision, sensitivity and specificity. Biological validation was achieved by demonstrating the typical mammalian circadian pattern of cortisol excretion. Potential relationships between levels of cortisol, visitor numbers and behaviour were assessed.

The research developed non-invasive tools to monitor HP A in an endangered primate and may have important management implications. Further more, the data may be used to facilitate our understanding of the role of the HP A axis in regulating the behaviour of social primates.

Does the hypothalamic-pituitary adrenal axis regulate social dominance interactions in Lemur catta?

McCusker, C.F., Elwood, RW & Smith, T.E.l

The hypothalamic-pituitary adrenal (HPA) axis is one of the major physiological components regulating the way an individual interacts with the social and physical environment. Many social species demonstrate a relationship between social dominance and activity in the HP A axis, although there is conflicting evidence on the direction of this association. The goal of the study was to evaluate the association between activity in the HP A axis and social dominance in captive groups of social primate, ring tailed lemurs, Lemur catta. There were three aims of the study. First we wanted to validate an enzyme-immunoassay to quantify levels of cortisol excreted in the faeces. Second we wanted to determine intra- and inter-sex dominance hierarchies in the species using the David's score. Third we wanted to investigate any relationship between HP A activity and intra- and inter-sex social dominance hierarchies. Focal animal behaviour data and faecal samples were collected from 22 L. catta housed in four social groups for 6 - 8 weeks each. Enzyme immunoassays (EIA) were developed to quantify levels of faecal cortisol by demonstrating accuracy, precision, sensitivity and specificity. Biological validation was obtained for the assays by demonstrating the typical circadian pattern of cortisol excretion. The relationships between levels of faecal cortisol and intra- and inter-sex dominance status were assessed for each group. The research will help to clarify the conflicting saga of the link between HP A activity and social status in group living animals. Results will also further our understanding of the role of the HP A axis in regulating social interactions patterns. In an applied context, we have developed non-invasive tools to monitor HPA activity (i.e. stress) in a primate species which could have potential management implications.

Solutions to a trap-table task: do gibbons (Hylobatidae) use simple associative rules for success?

Clare L. Cunningham & James R. Anderson

The cognitive abilities of gibbons, taxonomically apes, have been rarely studied. This research assessed gibbons' understanding of the causal relationships between a goal object, an object to be manipulated and an effecting environmental feature. Nine gibbons were presented with two rakes placed on tables outside their enclosures that could be pulled in to draw objects towards them. In a training phase, a simple discriminatory task required the subjects to choose between pulling in a rake that was baited with food versus one that was not. The testing phase introduced a trap along the surface of one table, into which the food could be lost. Both sets of apparatus were baited and the ape had to select a rake to pull in. Seven subjects effectively learnt to avoid the trap and retrieve the food. Further experiments tested a number of associative rules the gibbons may have employed to complete the task. Subjects were not avoiding what they may have perceived as an obstacle in the path of the reward and when presented with two traps, one of which was ineffective as the food was placed after the trap, most subjects avoided the effective trap. Further variation determined whether gibbons were selecting using a distance-based rule and found that this was not the case. There were significant differences in the performances of the four genera with Bunopithecus being the most consistent and proficient at avoiding the trap. No tested species or individual of the genus Hylobates successfully completed the training phase.

Studying Wild Chimpanzees in Senegal

Linda F. Marchant

Knowledge of the biology and behavior of chimpanzees by the public and by non­specialist audiences is based mostly on those populations of apes who are well ­accustomed to close-range observation and who live in forested or woodland sites in Africa. However, chimpanzees also occur in a variety of other habitats, including savanna. This video illustrates a field season spent at Mt. Assirik in the Niokolo-Koba National Park in southeastern Senegal. Assirik is the hottest, driest, most open habitat where chimpanzees have been studied. Most of the landscape is grassland and less than 3% is evergreen gallery forest, found only along the few permanent watercourses. These chimpanzees live at lower population densities in far larger home ranges than do their forest-dwelling counterparts. This program describes the special research methods needed to help us understand chimpanzee diet, activity, ranging, resource distribution and availability, and genetic variability in a habitat where the chimpanzees have yet to accept close-range observation. The film also shows what it is like to live and work at a remote field site. Research on savanna chimpanzees adds to our knowledge of the behavioral flexibility of our nearest living relations. These apes may also serve as a useful referential model for palaeoanthropologists seeking to understand how our earliest human ancestors may have emerged. The Phi lip and Elaina Hampton Fund of Miami University, LS.B. Leakey Foundation, National Geographic Society, and Primate Conservation International supported this research.

Macaques (Macaca nemestrina) recognise when they are being imitated

A. Paukner, lR. Andersonl, E. Borelli, E. Visalberghi& P.F. Ferrari

Even though monkeys are generally regarded to be incapable of imitating, the present study showed that monkeys can recognise when they are being imitated. Ten pigtailed macaques were faced by two experimenters while given access to an interesting object. One experimenter imitated the monkeys' object-directed actions, the other performed temporally contingent but structurally different object-directed actions. Results indicate that the monkeys showed a significant visual preference for the imitator during manual object manipulations, but not mouthing actions. We argue that the ability to match actions could be based on both visual-visual and kinaesthetic­visual matching skills and that mirror neurons, which have both visual and motor properties, could serve as a neural basis for recognising imitation. However, imitation recognition as assessed by visual preference does not necessarily imply the capacity to attribute imitative intentionality to the imitator. The monkeys might implicitly recognise when they are being imitated without deeper insight into the mental processes of others.

An indirect reputation experiment in four great ape species

Yvan, Russell, Josep Call, Robin  M. Dunbar

Reputation is defined as a knowledge of a person's typical behaviour based on that person's past behaviour. Indirect reputation refers to knowledge gained from observing events between third parties. This experiment was devised as a methodology for learning about indirect reputation in non-human apes (inspired by a recent body of human experiments). Four great ape species were tested on a simple paradigm where every subject passively observed two types of food sharing incident that occurred between human actors. One (1) was a nice person incident (a "nice" person gives some of her grapes to a human who begged for them). The other (2) was a nasty person incident (a "nasty" person refused to allow the beggar to take any grapes). After observing both incidents, the subject was allowed into a compartment where both nice and nasty persons were sitting side-by-side at plexiglas windows (with open food holes). Both humans were holding a container of grapes but neither fed the subject. This was a test of which human (nice/nasty) the subject prefers to approach. One measure of preference was the percentage of seconds that the subject spent at either window. Only chimpanzees (n = 14) spent significantly more seconds at the nice person's window than the nasty person's. The results were not significant for bonobos (n = 4), orangutans (n = 5), or gorillas (n = 3). One interpretation of these data is that chimpanzees were using the passively observed incident to guide their subsequent food seeking behaviour.

Planning ahead?: The interchange of grooming and agonistic support in captive chimpanzees.

Nicola F. Koyama, Clare Caws & Filippo Aureli.

There is some evidence to suggest that anticipation and planning play important roles in the social lives of non-human primates. Examining whether the temporal sequence of behaviours matches that expected if individuals were able to plan ahead can enhance our understanding of such cognitive abilities in primates. We investigated the temporal relationship between grooming given and agonistic support received in a group of captive chimpanzees at Chester Zoo, U.K. Future recipients of support groomed future supporters more the day before they received support, compared to the day before conflicts-without-support and so grooming appeared to increase the likelihood of support. This relationship between prior grooming and support only held true for aggressor support and not victim support and is consistent with behaviour expected if chimpanzees anticipated the need for agonistic support and groomed their supporter the day before to increase the likelihood of support. We found some evidence for a system of reward and punishment. Supporters experienced reduced aggression whereas non-supporters experienced increased aggression the day after conflicts. We did not find any evidence to suggest that individuals who were unsuccessfully solicited were punished with aggression or a reduction in grooming. We did find however, that solicitors groomed those they solicited for support significantly more after unsuccessful solicitations than after support was given (but no differently to baseline) and so individuals may attempt to re-cement their relationship after an unsuccessful solicitation. The findings are discussed in the context of calculated interchange in chimpanzees.

Primate personality: Use of rating scales to assess individual differences in gorillas (G. g. gorilla) and pygmy chimpanzees (Pan paniscus).

Lindsay Murray

Despite mounting research into animal personality, particularly in chimpanzees, the other great apes have been seriously understudied. This paper presents data showing that rating scales can be applied to both gorillas and pygmy chimpanzees. Thirteen gorillas and four pygmy chimpanzees, at London and Twycross Zoos, were rated by multiple observers on a scale adapted from Stevenson-Hinde, Stillwell-Barnes & Zunz (1980). Mean ratings were then subjected to correlation analysis, and findings from the corresponding chimpanzee study's principal components analysis were used to identify underlying constructs of personality. Differences according to age and sex were identified; e.g. gorillas become slower, more solitary and less sociable, playful and fearful with age, but also more protective, females emerging as more intelligent and opportunistic than males; adult pygmy chimpanzees are more sociable and playful while adult gorillas are notably less so, than adults of the other species. Assessment of personality can then be related to individual differences between animals in the complex nature 0 their interactions and relationships with others. The paper will show how ratings correlate with behaviours, including grooming, play and aggression, illustrating how personality traits can be used to help predict and explain behaviour in these apes. More curious gorillas initiate more play, for example, whereas in pygmy chimpanzees, curiosity is related to rate of grooming. The patterning of scores for levels of confidence, sociability and excitability enabled the formulation of five personality types relevant to all the African ape species, and some personality profiles will be presented.

The Social Rehabilitation of Monkeys from The UK Primate Pet Trade

Andrea Donaldson & Rachel Hevesi on behalf of The Monkey Sanctuary Trust (MST)

Currently, UK legislation permits the keeping of primates as pets. With the exception of marmosets, a DWA (Dangerous Wild Animals Act 1976) license is required to legally own a primate. This particular legislation was designed to provide some protection to owners of exotic animals and it was not intended to ensure the animals' welfare. At present the MST estimates that more than 1,500 primates are being kept as pets throughout the UK. The Trust's research shows that many of these primates live in socially and environmentally poor environments.

Since 2001, the Trust has received 5 ex-pet capuchins, all of whom have exhibited stereotypic behaviour such as pacing, neck twisting or over-grooming and had little or no social experience. The long process of rehabilitation illustrates the importance of careful management to enable beneficial relationships to develop between socially naive and even psychologically damaged individuals as the monkeys learn how to communicate, cooperate and resolve agonistic scenarios. Captive management techniques require knowledge of wild behaviours and how to apply this in a relevant and appropriate way. Other essential aspects include an understanding of individual characters; design of territory and environmental enrichment that promotes psychological well-being. The Trust's experience at its own rescue centre and from other centres in South America is that the careful regulation of social relationships can hugely improve an individual's quality of life.

Dry season adaptations of the white-whiskered spider monkey (Ateles marginatus).

Johanna Maughan & Carlos Peres

In an investigation of adaptation to low fruit availability, we studied the diet and feeding ecology of the highly frugivorous white-whiskered spider monkey during the dry season of 2004. Our data were collected from the Cristalino Jungle Lodge, adjacent to the Cristalino State Park, northern Matto Grosso, Brazil, at the southern edge of spider monkey distribution. A habituated group of 21 white-whiskered spider monkeys were followed from dawn until dusk for over 500 hours. Feeding and social behaviour data were collected during systematic observations, whilst estimations of fleshy fruit abundance were determined through a phenology study of 200 trees and biweekly walks on pre-cut transects. The latitudinal position of their habitat range in the southern Amazon makes these animals unique in that they are subject to highly seasonal patterns of fruit production. Our study therefore, revealed a variety of interesting adaptations previously undocumented in other spider monkey populations, including increased 'fusion' in the group, cohesive group movement, domination of large fruiting trees through antagonism towards other primate species, and regular travel to seasonally flooded forest for bark consumption. These findings will be discussed in terms of the extreme regional deforestation endangering this sub-species and with reference to other spider monkey populations.

Investigating a baby market in wild spider monkeys

Kathy Slater, Colleen M. Schaffner& Filippo Aureli

The presence of young infants has been found to influence female primate social behaviour, in particular social grooming, which may be exchanged for infant access within a biological market place (Henzi & Barrett, 2002). We investigated the effect of a baby market in two groups of wild spider monkeys (Ateles geoffroyi yucatanesis) from the Otoch Ma’ax Yetel Kooh reserve in Yucatan, Mexico. Rates of approaches, social grooming and species-specific friendly behaviour (kiss/embrace/pectoral sniff) received by 15 adult females, while with infants less than 6 months old and at all other times were compared. The overall rate of grooming was extremely low and was not influenced by the presence of infants. However, rates of approaches and friendly behaviour received were higher when females had infants compared to all other times. Females did not approach or give friendly behaviour at higher rates when they had infants indicating that the increase in friendly behaviour received was due to increased interest from non-mothers and not simply a general increase in sociality. Females with infants also received more friendly behaviour than they gave further suggesting an exchange of friendly behaviour for infant access. The finding that grooming was unaffected by the presence of infants is not surprising as spider monkeys use species-specific behaviour rather than grooming to regulate their social relationships. Embraces, kisses and pectoral sniffs are believed to reduce tension and facilitate cooperative interaction by signalling benign intent. However, due to the associated risk of personal injury to the initiator, these behaviours are costly suggesting that like grooming, these behaviours may be traded for other commodities in a biological market place.  

The dynamics of spider monkey aggression in zoos

Davis, N., Schaffner, C.M., Wehnelt, S.

Reports on spider monkeys in the wild indicate that aggression is infrequent and typically directed by adult males towards adult females. However, observations on a group of spider monkeys at Chester Zoo indicated that, although rare, male-male aggression did occur and had resulted in serious injuries. A survey was developed to investigate the frequency, direction, intensity and context of aggression in zoos and sent to 55 breeding collections around the world. We received a response from 32 of these zoos. The age and sex of spider monkeys that initiated and received aggressive attacks and a description of the severity of injuries inflicted are documented. Aggression within groups was reported in 76% of respondents, with 69% of incidents serious enough to warrant veterinary treatment. Adult males were the most likely aggressor (47.9%) while non adult males accounted for a large percent of the targets of the attacks (37.5%). This prevalent pattern of aggression between males had direct implications for the management of the spider monkeys, including the break-up of social groups and in seven instances the death of individuals. Our findings suggest that male-male aggression is potentially problematic in zoo populations and has implications for how captive groups are managed.

Suckling in Mountain and Lowland Gorillas – Variation in Timescales Related to Feeding Ecology?

Alison W Fletcher & Angela A Nowell

Suckling of an infant is a costly activity for the mother in terms of energy expenditure and prevents her return to oestrus when suckling rates exceed a threshold level.  However, early cessation of maternal care may result in low infant survival, thus a balance must be attained between current and future investment in offspring to maximise reproductive success.

Two longitudinal studies of immature gorilla social development provide data on suckling behaviour in the wild.   Data are presented here for 15 immature mountain gorillas (Gorilla beringei beringei) of the Virunga Volcano Conservation Area in Rwanda and Democratic Republic of Congo, and for 39 immature western lowland gorillas (Gorilla gorilla gorilla) of Mbeli Bai, Republic of Congo.  Comparative data detailing suckling frequency and bout length throughout infant and juvenile periods will be presented, as will a discussion of termination rates by the mother.  Immature age at the last observed suckling attempt is utilised to give an indication of age at weaning.

Results show similarities between species in the progression of suckling through infancy, although rates for mountain gorillas were recorded as being higher initially and decreasing at a later age.  However, western gorillas continued to suckle for longer than mountain gorillas with the median age at last observed suckling incidence being 12 months later in western gorillas.  Temper tantrums were rare in both subspecies. We suggest that differences in apparent age at weaning may reflect the availability of suitable weaning foods in the environment: mountain gorillas are adapted to feed upon continually available herbaceous vegetation whilst the diet of western gorillas is ephemeral, varying according to seasonal availability of fruit.  Mothers should continue to nurse offspring until survival on alternative food resources is assured, which may be necessarily later in species where resources are unpredictable, resulting in relatively longer interbirth intervals.  Studies of maternal investment in gorillas are necessary to investigate these findings.

Changes in social interactions within a captive bachelor gorilla group over time and following changes in group composition: indications for the regulation of social relationships

Kirsten Pullen

The establishment of bachelor groups of gorillas in captivity has provided an opportunity for social behaviour research under a unique set of conditions, i.e. with virtually no need for intra-specific competition since most resources (food, space etc) are not limited and females are absent. Bachelor gorilla groups in captivity tend to be fluid in nature, with adult males moving out and young males being introduced as necessitated by captive breeding programmes.  Since the start of this study in 2001 the group at Paignton Zoo Environmental Park has progressed from 1 silverback, 3 blackbacks and 1 sub-adult to 3 silverbacks and 2 sub-adults through a process of transfers and introductions.

The dynamic nature of the group has influenced the establishment and regulation of social relationships between the individuals, as alliances have formed and been disrupted and the group hierarchy has continued to evolve.  Observational data has been collected in discrete periods to assess the development of social interactions within the group in response to group changes and over time.  The results indicate significant changes in social relationships between dyads and provide some interesting indications of possible mechanisms of their regulation. 

Physiological and behavioural dispositions vary across the callitrichid genus

Tessa E Smith & Josephine M McCallister

Pre-existing, underlying behavioural and physiological dispositions (i.e. temperament) are responsible for shaping the nature of interaction patterns defining social relationships and hence a species' social organization.  Primates of the family callitrichidae exhibit remarkably similar social systems.  One would thus predict all five callitrichid genera to share similar temperaments.  Alternatively, there are distinct differences between the callitrichid genera in feeding ecology, use of space and life history parameters that might have selectively shaped divergent, genera-specific temperaments.  The goal of the study was toassess links between social organization, ecology and temperament across a primate family by comparing behavioural and physiological disposition across three callitrichid genera: Callithrix, Saguinus and Leontopithecus. The study had 3 aims: First, since a major physiological underpinning of temperament is hypothalamic-pituitary-adrenal (HPA) activity and concomitant release of glucocorticoids, we validated enzyme-immunoassays (EIAs) to quantify levels of urinary cortisol for the three genera.  Second we assessed genera differences in baseline HPA physiology by quantifying levels of urinary cortisol throughout the day (0600 – 1700 hrs). Third we quantified behavioural response styles across the three genera by assessing baseline behaviour.  Levels of urinary cortisol varied significantly across the three genera with significantly lower levels in Leontopithecus compared to Callithrix and Saguinus.  Species from the three genera exhibited significantly different behavioural styles.  The results suggest there may be species –specific behavioural and physiological dispositions that could reflect genera adaptations to varying ecological and life history pressures.  

Poster Abstracts

Cataracts in a Laboratory Colony of African Green Monkeys (Chlorocebus aethiops)

Roland Plesker, Udo Hetzel, Werner Schmide

At the end of 2003, in a laboratory colony of African Green Monkeys, about seven per cent of all colony members (n = 6) were known to suffer from cataracts. The lenses were uniformly affected by the occurrence of irregular, white, opaque material. Clinically, these cataracts shared several common features like individual age of the affected individual at the onset of the disease, bilateral occurrence, similar clouding patterns, duration of clinical development, familiar accumulation and the lack of possible infectious agents. This led to the assumption that the colony might be affected by a single type of cataract with possibly one unique explanation for its occurrence. This consideration led to further attempts to investigate the cases of cataracts in our colony.

Three cases of spontaneous cataracts were investigated in our colony. Clinical, pathological and microbiological investigations were conducted in two cases of juvenile cataracts and in one case of a mature cataract. These investigations revealed no indication of an infection as the cause of cataract development. A genetic correlation existed between the affected individuals. Clinical chemistry gave a hint that calcium might be a "key factor" in the development of these cataracts: In both cases of the juvenile cataracts, the calcium content in the serum and in the aqueous humor was clearly decreased in the affected babies. The calcium uptake in the affected baby itself was not altered but the calcium content in the mother's milk was Iow.

The possible role of DRD4 VNTR in the regulation of social behaviour

Ursula Paredes-Esquivel, John. P. Quinn, Vivien J. Bubb & Gabriele A. Mach¹

Dopamine regulates executive function of the brain, such as social, attentional, and motor processes. The dopamine receptor D4 (DRD4) is activated by dopamine in the brain, and amplifies the signal carried by dopamine. The DRD4 is mainly distributed in the prefrontal and cingulate cortices, indicated as the social and cognitive areas in the brain. The DRD4 gene has a functional hypervariable polymorphism VNTR (variable number of tandem repeats) that affects gene production in vitro. As the DRD4 VNTR is present in non-human primates and modern humans alike, and given their role in social behaviour in the latter, we investigated the correlation between VNTR structure and group size in non-human primates.

DNA was extracted from tissue, blood and hair samples. The VNTR region was amplified from the DNA samples using the Polymerase Chain Reaction (PCR). Additional primate VNTR sequences were also obtained from the NCBI data based. Analyses of the VNTR sequences revealed a homologous VNTR structure across the order Primates. The VNTR is formed by variable repeat units and these formed stable motifs present in almost all primates. Among all species, Tarsius bancanus VNTR shows the biggest difference (29%) from the consensus VNTR sequence (12% average dissimilarity across all primates analysed). The VNTR of monogamous Hylobates also exhibits big differences (17%). The majority of the repeats forming the Pongo VNTR were the same in all individuals analysed and were unlike those in all other primates. Cladistic analysis of the DRD4 VNTR based on motif prevalence and repeat variability showed a clustering of monogamous (Hylobates spp.) and small family group species (Saguinus fuscicollis) in Anthropoidea. Lemur catta, a highly social prosimian, clustered with Anthropoidea rather than to solitary Otolemur and Nycticebus that are phylogenetically closer. Tarsius and Tupaia remained as unresolved branches.

The results suggest that the DRD4 VNTR repeat variability and motif may be correlated with group size and social organization in the order Primates, indicating a possible role of the VNTR as a regulatory factor in of social behaviour processes in the brain.

The behavioural and endocrinological adjustment of callitrichid monkeys to relocation

Nicola Forshaw, Colleen M. Schaffner, Tessa E. Smith

Relocation is a useful management strategy that is of particular importance when maintaining endangered species in zoo collections. However due to the potentially disruptive nature of the relocation process, it is essential to monitor the behavioural and physiological adjustment of the relocated animals to ensure their welfare is not compromised. The aim of this study was to investigate the behavioural and physiological response of four callitrichid monkeys during relocation to Chester Zoo, UK. The subjects consisted of a newly formed breeding pair of Geoffroy’s marmosets (Callithrix geoffroyi) and a related female pair of Pied tamarins (Sauinus oedipus). Subjects were studied for 18 weeks following relocation to Chester zoo. Subjects had access to the indoor section of the enclosure for the first 8 weeks after which they were also allowed access to an outdoor area. The physiological state of the subjects was monitored by quantifying levels of cortisol excreted in urine and faeces samples collected four to five times per week. Focal animal behaviour observations were also conducted twice daily on each animal, five times per week and involved monitoring affiliative, agonistic and stress related behaviours. Behavioural data were analysed through the application of randomisation tests and urinary samples were analysed using cortisol enzyme immunoassay techniques, previously validated for the two species. The results will increase our understanding of the relocation process and hopefully help to minimise the stress associated with moving animals.

Variation in dyadic relationship quality and behavioural assessments of social anxiety in wild chimpanzees

Nobuyuki Kutsukake

Current theory on primate social relationships implies that relationship quality consists of three factors: value, security, and compatibility. The relationship security of each individual can be determined using the level of social anxiety found when that individual is in the proximity of other group members. I investigated how the relationships security affects social anxiety in wild chimpanzees (Pan troglodytes schweinfurthii) in Mahale Mountains National Park, Tanzania. I used rough self-scratching behaviour (RSS) and vigilance behaviour as behavioral cues of anxiety. Close proximity of group members increased the RSS rates in females and the vigilance levels in males. The female RSS rate and the vigilance level of both sexes increased when a non-affiliative group member (defined by the low frequency of association) was nearby relative to when only affiliative group members were in proximity. The relative dominance rank of the individuals in close proximity did not affect the RSS rate or vigilance level in either males or females. In addition to the relationship quality, infant condition affected the maternal anxiety level: the level of maternal vigilance was higher when a dependent infant was separated from its mother than when the offspring was in contact with its mother. These results suggest that relationship security is related to association level and that variation in relationship quality influences the social anxiety level in wild chimpanzees.

Video-mediated behaviour in gorillas: Evidence of self-recognition in a juvenile male?

Lindsay Murray

The anomalous position of gorillas (G. g. gorilla) in the capacity for self-recognition remains puzzling. The standard measure of self-awareness is Gallup's (1970) Mark test of self-­recognition, assessing an individual's ability to recognize its altered image in a mirror following the application of paint spots (administered under anaesthetic) to areas not otherwise visually accessible. The study reported offers an alternative non-invasive procedure, utilizing video playback through a TV monitor. Four lowland gorillas at Bristol Zoo were observed while watching the TV screen during each of 5 conditions: blank screen, interference, unfamiliar gorillas, self previously recorded, and self live. During live playback, various behaviours indicative of a transition in nature from other-directed to self-directed were evident, including image-testing movements and exploration of the mouth. The five year-old male, Jeremiah, provided a close parallel to mouth exploratory behaviour witnessed in self-recognizing chimpanzees, and this evidence remains to date one of the very few instances of apparent self -recognition in gorillas. Data not previously published are presented showing significant differences in frequency and type of behaviour under each of the experimental conditions.

Do chimpanzees build comfortable nests?

Fiona Stewart

A study of wild chimpanzee (Pan troglodytes verus) nests was conducted at the Fongoli, Southeast Senegal, from January to May 2004, to investigate if there was a correlation between nest building effort and nest comfort. Nest comfort across zones of the nest surface was compared with construction effort of25 nests. Comfort levels were assessed with three different variables: 1) the unevenness of the surface (rises, branches lying beneath or across the surface, hard and sharp points of pressure), 2) visible discomfort (branches lying across nest surface) and 3) softness. Nest construction effort was measured in two ways: 1) the relative force necessary to break and bend branches involved in construction, 2) the complexity of nest construction assessed on a scale of 1-4. The results show that force of construction and nest complexity do not influence total nest comfort. Higher force of construction results in a more uncomfortable area around the edges of nests, although the central area shows no reduction in comfort. More complex nests do, however, result in a more comfortable central area in the nest. Nests built with greater force may result in more possibilities for discomfort, but the complexity with which nests are constructed may allow chimpanzees to maintain the comfort of a central area for sleep. Chimpanzees may place additional leaves or twigs over hard branches, remaining on the nest surface after construction, to increase comfort of the central nest area.

Strategies for Water Obtainment by Procolobus kirkii in Saline Environments

Katarzyna Nowak

Rhizophora mucronata-dominated mangrove forests serve as refuge for groups of Procolobus kirkii inhabiting Uzi Island, southeast of Zanzibar Island, Tanzania. Monkeys spend most of their day in the mangroves with brief excursions to upland coral rag forest. A large proportion of their diet thus consists of the mature and young leaves, flowers and seeds and fruit, of 5 species of mangroves. Individuals of three study groups were observed, over a period of 12 months, to different strategies to obtain water including licking dew off of R. mucronata leaves during morning hours, drinking from treeholes, licking rain off of leaves and tree trunks, and drinking from holey coral rocks with Cercopithecus mitis. All occurrences of water-drinking were recorded resulting in a total of 324 records. One group, on average having 30 individuals, was habituated by local people for tourism through water provisioning and monkeys consumed up to 20 liters of water over a two-day period. Differences in strategies for water obtainment cannot only be attributed to the slight variations in habitat attributes of groups' adjacent territories but also to differences in the frequency of inter-species interactions between P.kirkii and C.mitis and P.kirkii and Homo sapiens. As one dozen deaths from drought were recorded in other parts of the Island, it is presumed that both the short and the extended dry seasons may lead to a decline in the P.kirkii populations, living in mangrove habitats, which fail to learn to obtain or be provisioned with sufficient water.

An Evaluation of the Education at the Cotswold Wildlife Park.

Alice Crichton

Through focused education that targets specific audiences, the potential to educate in zoos is vast. Education in zoos worldwide, offers people the chance to learn about the magnificence and plight of exotic and endangered species. However, this potential is easily lost if education departments in zoos do not appreciate the desire to learn and target the right audiences. This research evaluated the education at the Cotswold Wildlife Park by asking visitors' and teachers' what they wanted to see in terms of education. This was done through a visitor questionnaire and teacher survey. From the results it was found that the majority of visitors wanted to learn new things as part of their visit and learnt best through certain displays of information, specifically through graphics. Teachers also felt that aside from keeper talks, additional resources that linked endangered animals and the National Curriculum would be beneficial. In response to these findings, recommendations were suggested that included the design of new signs and a teacher's activity pack. The aim of this research was to encourage zoos to evaluate their own education departments and programmes, to assess whether what they were providing was appropriate to their visitors and whether anything was actually being learnt.

Training Marmosets to Cooperate With Aversive Laboratory Procedures

VerityA. Bowell, Hannah M. Buchanan-Smith & Keith Morris

Whilst it has been shown that by using positive reinforcement training (PRT), marmosets will cooperate with data collection in the laboratory (e.g. for in-home cage weighing), the tasks are not aversive. Macaques have been trained to present for venipuncture but this has used both positive and negative reinforcement. No study has investigated whether it is possible and practical to train marmosets to cooperate with aversive procedures using only PRT. Seven pair-housed adult female common marmosets (Callithrix jacchus) who were blood sampled three times per week were used. They were trained to enter a transport box using PRT. Training was then transferred to when blood sampling was carried out. Marmosets had four training days where they were requested to enter the box at the time when they would be caught for blood sampling. They were then requested to enter the box for capture on the following four blood sampling days and four non-blood sampling days. Success rate and time to initial entry were recorded. Training was considered to have failed if the monkey was not caught within 300 seconds from the opening of the box door. Capture in the transport box was 100% reliable on training days, but this dropped to 64.3% reliability on blood sampling days and 50% reliability on non-blood sampling days. These preliminary results suggest that using solely PRT is not entirely realistic training for aversive procedures. It is recommended that if NRT must be used it should be paired with PRT.

Does Zoo Visitor Noise Affect Primate Behaviour?

Authors: Alexandra Farrand & Hannah Buchanan-Smith

Many variables associated with the presence or behaviour of zoo visitors, such as visitor noise, have been hypothesised to have a negative effect on primate behaviour and welfare. However, non-human primate data to support this hypothesis are limited. Previous research supporting the hypothesis that visitor noise effects primate behaviour is methodologically flawed because it presents unrealistic noise stimuli to the study animals and lacks an objective measurement of visitor noise. This study examines the relationship between visitor noise and behaviour in three primate species (Leontopithecus rosalia, Gorilla gorilla gorilla, and Pongo pgymaeus) which suggests that visitor noise, as a discrete variable, may not have a significant impact on behaviour or welfare of the study groups.

Orang-utans Manufacturing and Use of Tools with Long-term Enrichment and Short-term Enrichment at the Los Angeles Zoo

Kelly Ablard

The close relationship between humans and apes has inspired numerous studies regarding great ape cognition. Cognitive abilities exhibited by the great apes include being able not only to manufacture and use tools, but to do so in a creative and flexible manner. Russon (1999) stated that orang-utans (Pongo pygmaeus pygmaeus and P. p. abelii) are stereotyped as being "slow-moving, the most obtuse, stupid, and boring of the apes." However, captive orang-utans, for the most part, live in a very comfortable environment, where challenges do not confront them as in their natural habitat. Therefore, manufacturing and using tools in captivity may not be common, even if such behaviours are observed under natural conditions. An observational study was conducted on four orang-utans residing at the Los Angeles Zoo to ascertain whether or not these orang-utans manufacture and use tools from both their long-term enrichment (permanent) and short-term enrichment (daily varieties). I wanted to determine if they are creative and flexible with their tool use, using the same tools for different tasks, and different tools for same tasks. My observations showed that items from short-term enrichment were used more frequently (63% of the time) than items from long-term enrichment (37% of the time), and that some items of both types were used creatively. The implication o this research can be beneficial for enhancing enrichment for other captive orang-utans. It corroborates past research and provides preliminary findings for future research which can further contradict the stereotype of orang-utan cognition.

'Letting the animals decide'- does positive control affect the welfare of captive common marmosets?

Inbal Badihi & Hannah M. Buchanan-Smith

Several researchers have argued that increasing the amount of control that primates have over various aspects of their environment has a positive effect on the welfare of the animals. Nevertheless, little research has been done in this field. In our study we allowed six small family groups of common marmosets (master groups) to control the lighting conditions in their cages (additional to the regular room illumination). The light intensity inside the cages without additional light was 3fc while with additional light was 8fc. The monkeys could turn the light on/off by touching a touch sensitive button at any time between 0700-1700hrs for 18 consecutive days. We compared the behaviour of the monkeys in these six master groups to the behaviour of six unaffected groups. Although, only three out of six groups kept the light on for long durations, all master groups were positively affected from the ability to control their environment. The monkeys in these groups showed significantly more calm locomotion and self play behaviours, while they also spent less time inactive and watching the observer compared to the unaffected groups. When comparing the youngsters only, those in the master groups also showed less agitated locomotion and scent marking behaviours, more play behaviour and spent more time in the lower part of the cage than the youngsters in the unaffected groups. To examine the effect of the light itself, a comparison was made for all the master groups between the two conditions ­light on and light off. Here again, the differences were more significant for the youngsters. They spent more time in play behaviour and calm locomotion, while less time in contact and inactivity when the light was on. The results of this study support the hypothesis that control improves welfare, and additionally they have implications for guidelines on illumination.

Hand use in humans and chimpanzees - no tools, no laterality?

Anna L Murray and Alison W Fletcher

Laterality of hand use has been widely studied in chimpanzees due partly to the hypothesised link between laterality and the evolution of language in humans. Although research on different populations has provided differing results, there is some evidence that manual activity during tool use is more lateralised in chimpanzees than when they conduct simple, spontaneous, non tool-using tasks. Surprisingly, there has been a lack of comparative study of the latter in humans to establish if a strong population right-hand bias is still evident under such conditions.

The aim of this study was to examine simple, spontaneous, non-tool use manual activities in both humans and chimpanzees to investigate hand preferences. Seventy­-six categories of spontaneous hand use, defined from an initial pilot study, were observed in 11 voluntary human participants, five male and six female, aged between 20 and 25. Observations of five male and six female semi-free ranging chimpanzees, of Chester Zoo, UK who were matched for sex and maturity, provided data on 48 categories of spontaneous hand use. Data were collected using switching focal animal sampling of all spontaneous hand use. Analysis of the data was carried out using standard statistical tests of binomial data.  Results are discussed in terms of comparative laterality.

Notifying behaviour in captive Hamadryas baboons: resolution of conflict?

Andrew King

Paignton Zoo Environmental Park has a captive population of over 50 Hamadryas baboons (Papio hamadryas). Hamadryas baboon society is characterised by one male units or harems, consisting of a dominant adult male, a number of females and their offspring. This study considered the function of formalised, stereotypical “notifying” behaviour by adult males (whereby one male quickly approaches, looks at, presents to, and then leaves another male) in the resolution of aggressive conflict between two former opponents. Spatial associations for each adult baboon were also analysed with respect to individual aggression and notifying behaviour. Each adult male baboon (and their harems) was found to be spatially distinct from one another, though stronger associations did occur between pairs of males, suggesting the occurrence of “clans” or “two-male teams” reported in wild Hamadryas populations. Notifying behaviour occurred significantly more in post conflict situations compared to matched control sessions and may function in the resolution of aggressive conflicts between two former opponents. Notifying behaviour also occurred infrequently outside of aggressive contexts (10 times less likely) and may serve to resolve multiple situations requiring negotiation.

The Primate Pet Trade in Indonesia: A Rural Perspective

Juliet Wright

The extent of the live-trade in pet primates across Indonesia is largely unknown. Studies to date have focused on trade at markets in urban areas, but other aspects of the primate pet phenomenon, such as extraction and non-commercial acquisition, have been ignored. This study assessed the magnitude of and the attitudes towards a primate pet trade, adopting a rural perspective. 130 interviews with residents and 6 interviews with government officials were conducted on the island of Buton, Southeast Sulawesi, during July and August 2004. There was no strong evidence of a commercial trade; however, the extent of local pet ownership and the level of harvesting are cause for concern. 30% of respondents had owned a primate pet and extrapolations suggested that 184 primates could be kept as pets in Buton at any one time. Trends revealed a substantial increase in primate pet ownership over the last 15 years. Findings indicate that negative attitudes towards wild primates, and the primary reason for the acquisition of primates as pets, stem from the human-primate conflicts induced by human encroachment and the crop-raiding behaviour of macaques. Farmers view eradication of the Buton macaque (Macaca ochreata brunnescens) as a favourable option and the current level of law enforcement in Indonesia does not prevent this.