No description available.

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

No description available.

This study comprised three questions, each posed with the intention of exploring the expression of the neurofilament protein (NF) and mRNA levels in the monkey lateral geniculate nucleus (LGN) and visual cortex. (1) Literature indicates NFs are differentially expressed across the two visual pathways that originate from magnocellular and parvocellular layers in LGN. The results herein suggest that this difference continues at the level of gene transcription for the neurofilament heavy gene. (2) NF expression, assessed by SMI-32 (an antibody that recognizes an epitope of the non-phosphorylated NFs), was investigated as a function of developmental changes occurring during the critical period in area V1 of the vervet monkey visual cortex. The findings indicate that the M pathway develops before the P pathway. (3) The effect of eye enucleation on long-term changes in NF expression was investigated. The results do not support the idea that NF are activity-dependent.

The distribution of vervets in Barbados was not uniform across the island, vervets being more abundant in parishes with high vegetative cover and low human population density. Ranging patterns for 4 troops of vervets in Barbados were shown to be influenced by the maximum daily temperature and the mean daily humidity. The frequency of use of an area decreased with increasing distance from the sleeping site, and the duration of use increased with increasing distance from the sleeping site. An interpopulation comparison of home range size and ranging patterns of vervet populations from Africa and St. Kitts, showed a positive correlation between home range size and group size and a negative correlation between home range size and population density. / The genetic structure of the Barbados population was characterized by relatively high levels of heterozygosity and gene diversity at the group level, and small genetic distances between groups indicating adequate gene flow between groups. Three of the 6 polymorphic loci investigated showed differences in allele frequency between east and west sub-populations of vervets, indicating some genetic differentiation.

Fifty-eight fecal samples from vervet monkeys (Chlorocebus [Cercopithecus] aethiops) at a sanctuary near Tzaneen, Limpopo Province, South Africa, were collected and analyzed to determine which species of gastrointestinal parasites they harbored, and differences in infection rates were examined. Three parasites were found, including two nematodes (Trichuris trichiura and one tentatively classified as Strongyloides spp.) and one protozoa (Balantidium coli). Rates of B. coil and Strongyloides spp. infection were similar in captive (41.9% and 77.4%, respectively) and wild (35% and 75%, respectively) monkeys, but rates of T. trichiura infection were significantly higher in wild individuals. No captives were infected with T. trichiura, but 15% of wild monkeys were infected. Although humans in other regions of South Africa have already been found to harbor two of these parasites (Strongyloides spp. and T. trichiura), caution should still be taken in areas that experience high rates of human-vervet interaction or conflict. Also, evidence suggests that the vervets may have been exposed to B. coil from a nearby pig farm, indicating that humans may pose as much of a threat to vervet health as vice versa. / Department of Anthropology

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

No description available.

No description available.

Self-directed behaviours (SDB) were recorded as a behavioural indicator of arousal in free-ranging vervet monkeys (Chlorocebus aethiops) inhabiting the Klein Karoo of South Africa. Measurement of SDB allowed for changes in arousal to be correlated with particular social situations, potentially providing insight into how monkeys perceive their social world. The research presented here is divided into three core chapters demonstrating that 1) arousal is influenced to a greater extent by degree of association than by hierarchical rank, 2) that an individual‟s level of arousal is influenced by its neighbour‟s spatial location, and 3) that habituated animals that no longer perceive humans as a direct threat nevertheless continue to respond to their presence in other ways. Overall, SDB appears to be a useful, non-invasive, simple means of investigating social arousal and its use has elucidated several key findings regarding the perception of social space and social partners in vervet monkeys. / ix, 103 leaves ; 28 cm