Thesis (M.S.)--University of Wisconsin--Madison, 1985. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 17-21).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The aim of this thesis was to provide a better understanding of the needs of spider monkeys (genus: Ateles) kept in zoological parks in order to provide an appropriate environment, which enhances the physical and emotional wellbeing of the individuals. This series of studies adopted primarily a physiological approach that entailed measuring cortisol in urine samples collected over a seven year period to assess the impact of a variety of social and environmental conditions. My studies also involved behavioural observations and a questionnaire study to collect information from other zoological parks that maintain groups of spider monkeys. In order to address the aims of my research I first validated an enzyme immunoassay for urinary cortisol which allowed for the activity of the HPA axis to be measured to assess the physiological stress responses in spider monkeys. The first study assessed the impact of visitors on spider monkeys by comparing levels of urinary cortisol collected with visitor numbers and I found an increase in visitor numbers was associated with an increase in cortisol. This was the first time the physiological impact of visitors was investigated and supports behavioural researcher that visitors adversely impact on primates in zoos. The second study I carried out involved a questionnaires to investigate frequency, direction and intensity of aggression in zoo-housed spider monkeys in 55 other zoos around the world. The pattern of aggressions reported indicated severe and lethal aggression was relatively frequent among captive spider monkeys. Adult males were the most frequent actors of aggression and sub adult males were the most frequent targets, contradicting reports from wild spider monkeys. This aggression could be a condition of the management of spider monkeys in the zoos whereby males and normally transferred between zoos contradicting reports from the wild spider monkeys in which females would emigrate on reaching maturity. Next I investigated aggression, reproductive and separation stressors in the spider monkeys housed at Chester Zoo over a seven year period and measured their effects via changes in urinary cortisol prior to, at and following each event. Aggression had the largest effect, with targets and bystanders having the highest levels of cortisol on the day of aggression for severe and lethal aggression, respectively. When examining the reproductive events, cortisol levels were significantly elevated in the mother the week prior to and the day or birth, but were highest for bystander females on the day of birth. In the case of separations, cortisol was elevated when an individual was separated for longer than 24 hours for separations and less than 24 hours for reintroductions. Finally I investigated the replacement of the breeding male in the spider monkeys at Chester Zoo. Although a significant behavioural effect was identified in the adult females, there was little evidence of an increase in urinary cortisol among them. In addition, there were no instances of aggression between the adult males and the juvenile male in the group. Overall conclusions from this study indicate that the group of spider monkeys did demonstrate a varying stress response to a variety of social and environmental stressors associated with elevated cortisol levels and behavioural changes. However, there was no evidence of long term chronic stressors which are normally associated with poor welfare. This indicated that the environmental provided for this particular group of zoo-housed spider monkeys generally allowed for the individuals within the group to cope and adapt. In light these findings the study also makes a number of recommendations regarding the enclosure design, relocated of individuals and the gradual introduction of spider monkeys in zoos. The findings of this study are important as it contributes to our understanding of the physiological responses to stressors in a zoo environment and therefore has implications for animal management. It also identifies potential species specific requirements for the spider monkey that should be considered.

Animals living in groups are frequently exposed to conflicts of interest which can escalate into aggression. Aggressive interactions may be a means to resolve incompatibility among objectives. Nevertheless, aggression may undermine the benefits of group living by disrupting the relationships between opponents. Thus, conflict management mechanisms have evolved to cope with the potential damage brought about by aggressive interactions. The aim of my thesis was to investigate the mechanisms to prevent aggressive escalation and to mitigate its negative consequences in 2 communities of wild spider monkeys (Ateles geoffroyi yucanensis). I also examined the factors, such as relationship characteristics, affecting the occurrence of these mechanisms. Spider monkeys live in communities with a high degree of fission fusion dynamics in which individuals frequently split and merge into subgroups of variable composition. The implications of this social system for conflict management were also explored. To characterise spider monkeys’ social relationships, two components were identified and labelled compatibility and risk. These components were further related to relationship characteristics, such as kinship, sex combinations, and tenure in the community. Kin had more compatible relationships than non kin, but there was no difference for risk. Male-male dyads were characterised as being significantly more compatible and riskier than either female-female dyads or male-female dyads. Furthermore, individuals with longer tenure had riskier relationships than individuals with shorter tenure. Among the post-conflict management mechanisms spider monkeys did not engage in reconciliation, redirected aggression, or bystander affiliation. However, an option afforded by their high degree of fission fusion dynamics was used in the aftermath of aggression. Fission from former aggressors was more likely to occur within one hour of the aggressive conflicts than in control periods. Furthermore, individuals sharing riskier and less compatible relationships had significantly shorter latencies to fission compared to those with less risky and more compatible relationships. These patterns suggest that fission may function to reduce the possibility of renewed aggression and cope with increased post-conflict anxiety. Indeed, anxiety levels were higher in the recipients of aggression during the first 5 post-conflict minutes compared to baseline levels. Whereas fission may be a mechanism to cope with the negative consequences of aggressive escalation, fusion of subgroups could lead to uncertainty and hostility. Indeed, aggression increased in the first five post-fusion minutes compared to baseline levels. There was also an increase in post-fusion friendly behaviours, which may function as signals of good intentions. This view was confirmed as post-fusion aggression was reduced when friendly behaviours took place. In addition, shorter latencies of post-fusion aggression and friendly behaviours were found between individuals with riskier relationships compared to those with less risky relationships. Prevention of aggressive conflicts may also be achieved by adjusting subgroup size to the availability of feeding resources thereby reducing competition. The effectiveness of this flexible adjustment was demonstrated during a period of drastic reduction in food sources caused by two consecutive hurricanes at the field site. Mean subgroup size and fusion rates were significantly reduced in the post-hurricane compared to pre-hurricane periods. Hence, my thesis adds to the study of social relationships and conflict management in non-human animals by making several contributions. I provided the first evidence of relationship components in new world monkeys. I then examined the potential of fission-fusion dynamics as a means to manage conflicts among community members. I was the first demonstrating that fission is a post-conflict mechanism. Fission from the former aggressor was especially used by individuals with riskier and less compatible relationships. Subgroup fusion increased aggressive conflicts, especially between individuals with riskier relationships, but post-fusion friendly behaviours reduced them. The effectiveness of fission-fusion dynamics in conflict management was further demonstrated by how the spider monkeys coped with the potential increase in conflict among community members due to a dramatic reduction in food supplies due to two hurricanes. Overall, spider monkeys appear to deal with conflicts using the full range of the flexible social options afforded by their social system.

No description available.

A 12-month study of the ranging behaviour of 11 spider monkeys (Ateles geoffroyi yucatanensis) was undertaken at the Otochma' ax Yetel Kooh nature reserve in the state of Yucatan, Mexico. The aims were: 1) to evaluate the relationship between ranging patterns of the monkeys and ecological features i.e. climate and food distribution, 2) to assess the efficiency of ranging patterns, and 3) to test the hypothesis that spider monkeys navigate between important sources through spatial memory of key locations. A focal animal was followed daily for as long as possible and details of its ranging patterns recorded by entering positional fixes with a GPS receiver. Behavioural states were included in the observations to link them with the geographical information recorded simultaneously. The results revealed that the ranging patterns of spider monkeys at the study site were determined by the availability of key species of fruit in the area. Ranging was efficient, as evidenced by the fact that in most instances - particularly in the dry season when food was scarce - (1) spider monkeys moved in straight lines to distant food sources, (2) were able to orient their movement toward a food source at distances that could not have been in sight from the point where directed movement originated, and (3) the successive organisation of these linear segments was consistently forward, suggesting an ability to plan ahead of the next food source visited. I present these results as evidence of the use of spatial memory to move efficiently between important sources in their environment, and I argue in favour of higher-level spatial abilities in this species of New World monkeys.

<p>For many years, primates have been considered to be animals with a poorly developed sense of smell. However, in recent years several studies have shown that at least some primate species have a high olfactory sensitivity for a variety of odorants. The present study used a two-choice instrumental conditioning paradigm to test the olfactory sensitivity for six aromatic aldehydes in four spider monkeys (Ateles geoffroyi). With helional, cyclamal,canthoxal and lilial all animals discriminated concentrations below 1 ppm from the odorless solvent, with single individuals even scoring better. With 3-phenyl-propionic aldehyde all animals detected concentrations below 2 ppb, and with bourgeonal even below 0.3 ppb. The detection thresholds of the odorants changed systematically with molecular structure. Addition of a dioxo or methoxy group to the benzene ring led to an increase in threshold values,while the absence of a methyl group close to the aldehyde moiety was linked to a low threshold value for the odorant. The study shows that spider monkeys have a well developed olfactory sensitivity for aromatic aldehydes.</p>

For many years, primates have been considered to be animals with a poorly developed sense of smell. However, in recent years several studies have shown that at least some primate species have a high olfactory sensitivity for a variety of odorants. The present study used a two-choice instrumental conditioning paradigm to test the olfactory sensitivity for six aromatic aldehydes in four spider monkeys (Ateles geoffroyi). With helional, cyclamal,canthoxal and lilial all animals discriminated concentrations below 1 ppm from the odorless solvent, with single individuals even scoring better. With 3-phenyl-propionic aldehyde all animals detected concentrations below 2 ppb, and with bourgeonal even below 0.3 ppb. The detection thresholds of the odorants changed systematically with molecular structure. Addition of a dioxo or methoxy group to the benzene ring led to an increase in threshold values,while the absence of a methyl group close to the aldehyde moiety was linked to a low threshold value for the odorant. The study shows that spider monkeys have a well developed olfactory sensitivity for aromatic aldehydes.

Studies on taste perception in nonhuman primates contribute to the understanding of the evolution of the sense of taste. To assess the responsiveness of four adult spider monkeys (Ateles geoffroyi) to a set of substances perceived as sweet by humans, two-bottle preference tests were performed to determine taste preference thresholds, and taste-induced facial responses were analyzed. The spider monkeys displayed a significant preference for concentrations as low as 0.2-1 mM acesulfame K, 0.002-0.5 mM alitame, 10-20 mM isomalt, 0.002-0.5 mM sodium saccharin, 2-20 mM galactose and 20-50 mM sorbitol over water. The spider monkeys were generally unable to perceive aspartame and, based on their facial responses, probably do not perceive it as sweet. Thaumatin and monellin were not detected, and most likely neither was the sweetness of sodium cyclamate. Sodium saccharine and sodium cyclamate were rejected at high concentrations by at least one monkey, which is congruent with the perception of a bitter side taste as reported in humans. A significant correlation was found between the ranking order of sweetening potency for the different substances of spider monkeys and humans, but not between spider monkeys and chimpanzees. The results suggest that spider monkeys may be generally more sensitive than chimpanzees and at least as sensitive as humans to the tested substances, supporting the notion that high sensitivity to sweet taste may be associated with a frugivorous dietary specialization. The lack of responsiveness to some of the substances supports the notion of a dichotomy in sweet-taste perception between platyrrhine and catarrhine primates.

Primates have traditionally been viewed as having a poorly developed sense of smell. However, in recent years, studies have shown that at least some primate species use olfaction in a number of behaviors, and that they have a high olfactory sensitivity for various chemical classes of odorants. Using a two-choice instrumental conditioning paradigm, the present study assessed olfactor ydetection thresholds of three spider monkeys (Ateles geoffroyi) for eight aliphatic alcohols and aldehydes, known as "green odors". With all odorants, the animals detected concentrations below 1 parts per million, with single individuals performing even better. The type of functional group present systematically affected olfactory detection thresholds, whereas the presence, position and configuration of a double bond did not. Compared to previously tested classes of odorants, thespider monkeys were not particularly sensitive to "green odors". Furthermore, they are lesssensitive for "green odors" compared to humans and mice. The present results suggest that neuroanatomical and genetic comparisons across species are poor predictors of olfactory sensitivity.