Hugh Notman

Primates of western Uganda

Taxonomy.- Taxonomy and Biogeography of the Primates of Western Uganda.- Ecology.- Factors Influencing Variation in the Population Densities of Colobus guereza, Within Selectively Logged Forest at the Budongo Forest Reserve.- How Does the Golden Monkey of the Virungas Cope in a Fruit-Scarce Environment?.- The Diet of Olive Baboons (Papio anubis) in the Budongo Forest Reserve, Uganda.- Aspects of Diet, Foraging, and Seed Predation in Ugandan Forest Baboons.- The Interaction of Hormones with Ecological Factors in Male Budongo Forest Chimpanzees.- The Role of Diet in Self-Medication Among Chimpanzees in the Sonso and Kanyawara Communities, Uganda.- Geophagy in Chimpanzees (Pan troglodytes schweinfurthii) of the Budongo Forest Reserve, Uganda.- Nutritional Aspects of the Diet of Wild Gorillas.- The Parasites of the Gorillas in Bwindi Impenetrable National Park, Uganda.- Preliminary GIS Analysis of Range Use by Sympatric Mountain Gorillas and Chimpanzees in Bwindi Impenetrable National Park, Uganda.- Behavior and Physiology.- Comparison of Sex Differences in Gregariousness in Fission-Fusion Species.- Urinary Estrone Conjugates and Reproductive Parameters in Kibale (Kanyawara) and Budongo (Sonso) Chimpanzees.- Frequent Copulations by Females and High Promiscuity in Chimpanzees in the Kalinzu Forest, Uganda.- Effects of Injury on the Locomotion of Free-Living Chimpanzees in the Budongo Forest Reserve, Uganda.- Effect of Snare Injuries on the Fig-Feeding Behavior of Chimpanzees of the Budongo Forest, Uganda.- Deciphering Junglespeak.- Instrumental Leaf Use by Chimpanzees of the Budongo Forest (Sonso Community).- Conservation.- A Survey of Prosimians in the National Parks and Forest Reserves of Uganda.- The Diets, Preferences, and Overlap of the Primate Community in the Budongo Forest Reserve, Uganda.- Behavioral Patterns of Colobus in Logged and Unlogged Forests.- Threats to, and Protection of, the Chimpanzees of the Budongo Forest Reserve.- Gorillas Living on the Edge.- Local Ecological Perceptions of Chimpanzees and Forest Resources.

Hunting of mammalian prey by Budongo Forest chimpanzees.

Chimpanzee (Pan troglodytes) predation has been found in communities across Africa. Little evidence of such behaviour has been previously reported from the Budongo Forest, western Uganda. Here we present preliminary observations of predatory behaviour for the Sonso community, collected between August 1994 and February 2002. We find that the Sonso chimpanzees do not appear to hunt frequently, despite a relatively high density of potential prey, particularly Colobus guereza and Cercopithecus mitis. They seem similar to other eastern chimpanzees in their focus on immature colobus monkeys and in targeting ungulates, and the absence of red colobus (Procolobus badius) - the most common prey species elsewhere for chimpanzees - may be a significant factor.

Assessing the Occurrence of Sexual Segregation in Spider Monkeys (Ateles geoffroyi yucatanensis), Its Mechanisms and Function

Sexual segregation is a recognized dimension of the socioecology of many vertebrates, but it has not been systematically examined in primates. We investigated temporal patterns of sexual segregation in spider monkeys (Ateles geoffroyi yucatanensis) using a test that distinguishes sexual segregation from aggregation and random association between the sexes. We further investigated how sexual segregation varies over time as a function of food availability, and then tested other possible factors that might be causally linked to sexual segregation in spider monkeys. We predicted that male philopatry and cooperative territorial defence leads to sexual dimorphism in behavior, which in turn creates different optimal energetic requirements for males and females as reflected in differing activity budgets and diet. We investigated sexual segregation in a group of 33–35 spider monkeys at Runaway Creek Nature Reserve in Belize over 23 mo in 2008–2009. We used the sex compositions of subgroups recorded in scan samples to test the occurrence of sexual segregation at monthly and biweekly time scales.We found that males and females were significantly segregated in 15 out of the 23 mo of the study, and that periods of nonsegregation coincided with months of low food availability. The sexes differed significantly in activity and diet; males spent more time traveling, and less time resting and feeding than females, and they had a higher proportion of ripe fruits in their diets than did females. We propose that sexual segregation in spider monkeys is primarily a form of social segregation that results from males and females pursuing optimal dietary and behavioral strategies to satisfy sex-specific energetic demands. We further suggest that sexual segregation represents an important constraint on fission–fusion dynamics that should be considered when assessing the potential for variability in subgroup composition.

Sex Differences in the Use of Whinny Vocalizations in Spider Monkeys (Ateles geoffroyi)

In species in which males and females exhibit different association patterns, the use of vocalizations that regulate interindividual distance may differ between the sexes. Spider monkey social groups are characterized by high fission–fusion dynamics and sex differences in association patterns; female–female associations have been described as more passive than those between philopatric males. Individuals of both sexes produce whinny vocalizations, which may allow callers and receivers to mediate interindividual spacing based on existing social relationships. As such, we hypothesized individuals of each sex would use whinny vocalizations at different rates and in different contexts. To investigate sex differences in the rate of whinnying across behavioral contexts, we collected focal animal samples on Yucatan spider monkeys (Ateles geoffroyi yucatanensis) over 8 mo at Runaway Creek Nature Reserve, Belize. In addition, we recorded all changes in subgroup composition to investigate whether a female’s likelihood of calling was influenced by the number of conspecifics joining, or leaving their subgroup. We found that females called at higher rates than males in most behavioral contexts, especially foraging. The probability that females would call increased during subgroup fissions and fusions, and correlated positively with the number of individuals joining or leaving their subgroup. Male calling rates did not differ across contexts, and males generally called less than females. Our results suggest that whinnying by females may allow callers to mediate interindividual spacing in contexts where proximity risks increasing feeding competition. In species in which the sexes associate in qualitatively different ways, vocalizations may play a role in maintaining these differences.

Seasonal and sex differences in the fission–fusion dynamics of spider monkeys (Ateles geoffroyi yucatanensis) in Belize

Spider monkeys (Ateles sp.) are characterized by high fission–fusion dynamics, meaning their social grouping pattern is fluid and consists of subgroups that vary in size, composition, and spatial cohesion over time. In this study, we quantify the fission–fusion dynamics of a group of spider monkeys at Runaway Creek Nature Reserve in Belize by measuring subgroup size, spatial cohesion, and stability using data spanning 5 years. We then test whether variation in these three subgroup measures differ according to season, subgroup sex composition, and the reproductive status of female subgroup members. Our results show that subgroups were larger in size and less stable in membership during the wet season compared to the dry season. All-female subgroups were less spatially cohesive but more stable in membership than all-male subgroups. Finally, we report that subgroups with one or more non-lactating females (i.e., without nursing young) were smaller on average than subgroups containing lactating females with nursing young. These data contribute to a growing body of research documenting the ecological and social dimensions along which grouping patterns might vary.