This study explores the effect of changing ecological conditions on female social organization among free-ranging vervet monkeys (Cholorocebus aethiops pygerythrus) in the Klein Karoo, South Africa. Comparison was made between a previous study conducted during a period of drought in 2009, and my own study conducted when conditions were much wetter and hence, less ecologically stressful. In addition, animals in the present study also experienced conditions of low demographic stress. Compared to 2009, females displayed lower rates of competition and aggression, did not compete for access to grooming partners, and did not preferentially groom those of high rank, nor did they do so more frequently. Females did, however, preferentially associate spatially with those they groomed most; a finding in contrast to the previous study. Females did not groom those of adjacent ranks more frequently, nor was there any relationship between rank difference and spatial association. In addition, there were rank differences in vigilance were found between females, and vigilance costs overall were affected by total group size. Overall, these findings support some aspects of the socioecological model used to predict group structure in primates, but other aspects of social organization remain puzzling, and may reflect larger overall group sizes in the Samara population, which changes patterns of engagement between females in ways not fully captured by current models. / xi, 122 leaves ; 29 cm

Thesis (M.Sc. (Zoology)) --University of Limpopo, 2001. / A South African rehabilitation centre for illegally kept vervet monkeys required an evaluation of the genetic status of vervet monkeys , to determine whether animals from different geographical areas may be kept in the same enclosures and mixed during release back into the wild. Animals originating from three geographical regions (the former Transvaal, KwaZulu-Natal and the Eastern Cape) were studied using biochemical genetic and morphological approaches to address this question. The most prominent trend from allozyme data was derived from the locus PRT-2 (an unspecified serum protein), where each of the three populations could be characterized by the absence or presence of unique alleles. A significant deviation of genotypes from Hardy­ Weinberg equilibrium was found at the PGD-1 locus in all the populations studied. Nevertheless, statistical coefficients indicated little genetic divergence, with genetic distance values of 0.001-0.003, gene flow values of 4.300 - 16.310 and an overall fixation index value of 0.046. Average heterozygosity did not differ appreciably among populations (2.5-3.3%). The morphological study identified suitable traits, free from the influence of growth allometry, which can be used for inter-population comparisons. No significant morphological differences between conspecific populations were however found. It is concluded that vervet monkeys from the species' wider distribution range is relatively monotypic, but that monkeys from different geographical areas should not be unduly mixed, pending the results of finer grained molecular studies.

Narrow riparian woodlands along non-perennial streams have made it possible for vervet monkeys to penetrate the semi-arid karoo ecosystem of South Africa, while artificial water points have more recently allowed these populations to colonize much more marginal habitat away from natural water sources. In order to determine the sequelae of life in these narrow, linear woodlands for historically 'natural' populations, I determined the size of troops in relation to their reliance on natural and artificial water sources and collected detailed data from two river-centred troops on activity, diet and ranging behaviour over an annual cycle. These data indicate that river-centred troops were distinctive primarily for their large group sizes and, consequently, their large adult cohorts, and the extent of home range overlap in what is regarded as a territorial species. While large group size carried the corollary of increased day journey length and longer estimated interbirth intervals, there was little other indication of ecological stress. Specifically, the rate of predation appears to be lower than observed at other sites. Predation encounters here, encourage the use of predator vigilance rather than influencing the use of space within the habitat. The high density of Acacia karoo, which accounted for a third of annual foraging effort in what was a relatively depauperate floristic habitat, allows for an adequate energy intake for groups of this size. I ascribed the large group size and home range overlap to the inability of groups to undergo fission. / xiii, 79 leaves : ill., maps ; 29 cm

The primary focus of the present thesis is the exploration of factors that influence the dopamine (DA) neuron by examining the expression of the dopamine transporter (DAT), a marker of the DA neuron. The secondary focus of this thesis is on the serotonin neuron and in particular the serotonin transporter (SERT), a marker of the serotonin neuron. To this end three distinct and separate models have been employed. The goals of this thesis were: (1) to test the hypothesis that monoamine oxidase inhibition during development alters serotonergic innervation in the cortex and raphe, while not affecting relative DA innervation of nigrostriatal pathway, (2) to test the hypothesis that elevated brain levels of hypoxanthine (Hx) deleteriously affect the DA neuron, and (3) to test the hypothesis that densities of DAT and SERT in brainstem cell body regions distinguish alcohol-preferring vervet monkeys with different behavioral patterns of ethanol consumption. / Alterations in the activity of monoamine oxidase (MAO), a degradative enzyme that plays an important role in regulating levels of monoamine transmitters, may have a profound effect on brain development. The present study investigates relative DA and serotonin innervation of cortical and subcortical areas, measured by DAT and SERT densities, following MAO inhibition (A or B or A+B) in mice throughout gestation and early post-natal development. DAT binding was unaltered within the nigrostriatal pathway. The most significant finding reported here is that the combined MAO-A+B inhibition significantly reduced SERT binding by 25% in both the cortex and raphe nucleus. Lower levels of SERT binding were apparent during the early post-natal period (PND 14), a period during which pups were still exposed to MAO inhibitors in the dam's milk, but also persisted into later life (PND's 35 and 90) after inhibitors were no longer being administered. Persistent effects were restricted to cortex and raphe, suggesting a relative vulnerability of these regions to alterations in monoamine transmitter levels during development. / The second study presents data demonstrating that Hx delivered intracerebroventricularly significantly reduces the number of tyrosine hydroxylase immunoreactive cells (TH-ir) in the substantia nigra by 22% and 30%, at 7 and 21 days, respectively. After 3 days of Hx administration, striatal DA and serotonin were elevated over control levels by 22% and 25%, respectively, but returned to control levels by 7 days. The serotonin metabolite 5-HIAA was elevated after 3 days of Hx, but levels of DA metabolites were not different from control. Locomotion, a behavior thought to be related to DA transmission, was elevated following Hx treatment, as were presynaptic markers of the DA system such as DAT and TH protein levels. The persistent reduction in TH positive cell numbers suggests that Hx damages or kills DA neurons. The increase in intracellular DA at early time points suggests that Hx might interfere with DA release, possibly by temporarily inactivating DA neurons. These findings are consistent with the hypothesis that Hx, a purine significantly elevated in blood and CSF of Lesch-Nyhan patients, maybe involved in DA dysfunction. / Studies on alcohol abuse have focused on the mesolimbic DA pathway and the serotonergic influence within this pathway. Here we report that abstinent binge-drinking monkeys have significant reductions of SERT binding, and to a lesser extent, DAT binding in the midbrain region, while abstinent heavy-drinking subjects have elevated levels of DAT binding, as compared to controls. Both mesolimbic and nigrostriatal pathways are affected. CSF levels of both HVA and 5-HIAA substantiate the neuroanatomical differences between binge- and heavy-drinking vervets. Taken together, these findings provide a neurochemical profile with which to further distinguish subtypes of alcohol-preferring vervet monkeys.

Two approaches were taken to investigating constraints on kinship in predicting social behaviour in the vervet monkey Cercopithecus aethiops sabaeus in Barbados. in Chapter 1, behavioural interactions between an adult female and an unrelated adopted infant were compared with those between mothers and their natural offspring. The adoptive mother consistently scored higher than mothers with their own offspring in pre-weaning contact-maintaining behaviours, but the difference was not statistically significant. Post-weaning aggression and support interactions between mothers and infants also suggest no difference in parental behaviour and parental costs between adoptive and natural mothers. During post-weaning, the adopted infant was more aggressive to other troop members, and provided more maternal support in aggressive disputes, than another high ranking infant of the same year. / In Chapter 2, effects of kinship on the distribution of aggression and support in feral vervet monkeys were investigated by comparing aggression and support between full sibs and maternal half sibs (within matrilines), and between paternal-half sibs and unrelated juveniles (between matrilines). The strong tendency to behave affiliatively to matrilineal members in Old World monkeys, and maternal control of offspring rank within matrilines, may constrain the ability of offspring to enhance inclusive fitness by behaving differentially to either paternal or maternal sibs based on their degree of relatedness.

I studied free-ranging vervet monkeys (Chlorocebus aethiops) in South Africa using focal animal sampling to test current theories of reproduction and maternal investment. Mothers cope with the energetic costs of lactation by feeding more than non-lactating females and targeting higher nutrient quality items as their infant ages. The dynamic nature of mother-infant interactions is highlighted, with infants spending less time in contact while the mother is moving and foraging. Other troop members “allomother” the infant primarily in the infant’s first couple of months. The length of investment is explored, with greater length of interbirth interval in low nutrient quality environments, larger troop sizes and higher survival rates. Maternal dominance rank and infant sex significantly influenced time in ventral contact, with low-ranking daughters spending more time in contact than high-ranking daughters. The findings from this thesis highlight the complex interaction of ecological and social conditions on maternal investment. / xiv, 182 leaves ; 29 cm

Thesis (Ph. D. (Dept. of Medical Biosciences)--University of the Western Cape, 2007. / Includes bibliographical references (leaves 215-239).

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Vervet monkeys (Chlorocebus pygerythrus) are generally described as a territorial species, though variations in territoriality have been observed. This research examined the impact of high population density, large group sizes and extensively overlapping home ranges on the expression of territoriality in a population of vervet monkeys. Over a period of eighteen months, data were collected on three large troops of vervet monkeys (PTN = 31, RBMN = 39, RSTN = 57) on the Samara Game Reserve, South Africa. I examined the spatial dynamics demonstrated in this population, assed the extent and use of home range overlap and examined the occurrence of intertroop encounters in relation to mate defence, resource defence and home range defence. The home ranges of the troops in this study population overlap substantially, and overlap areas are exploited extensively. The frequency of occurrence of intertroop encounters does not increase in the mating season, nor is there evidence of the defence of particular food patches or home range defence. The findings from this thesis emphasize the importance of examining the expression of territoriality of a population within the context of its environment. / xvi, 125 leaves : ill. ; 29 cm