Please read the abstract in the section 00front of this document / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

Sexual size dimorphism (SSD) defined by differences in body size of a conspecific male and female are widespread phenomenon in the animal kingdom and ungulates belong among the most dimorphic mammals. In most species males are the larger sex which is often explained by differing sex-specific reproductive roles. While parental investment is predominantly left to females which are the selective sex, males have to fight for access to receptive mates in intensive combats where body size, strength, and condition are often critical. The relationship between male body size and reproductive success varies according to a mating system with the highest SSD being achieved by harem and promiscuous species. Even though several compilation studies of SSD have been done on ungulates it is rare that systematic research is closely concentrated on a well-defined specialised homogenous group where detailed knowledge on its life-history traits is also available. I have focused on subfamily Caprinae and Bovinae with the objective to conduct a detailed analysis of their SSD and its evolutionary traits. Using advanced phylogenetic methods I could reconstruct the ancestral state in wild goats and sheep that was characterised by medium SSD which then took two different routes of evolution depending on a type of habitat and...

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In a number of publications serious concern has been expressed about 'the status of lechwe in the Kwando/Linyanti/Chobe system. Concern has also been expressed about the effects of possible water extraction from the Okavango Delta on the habitat of lechwe in the delta. This study was motivated by this concern and was undertaken to provide information that would facilitate the conservation and management of lechwe in Botswana. Continuous field work on the western edge of the Linyanti Swamp began in January 1975 and ended in May 1977. Follow-up visits were made in February/March and September/October 1979. Data were collected on the following: variation in water l6vels, physiognomic and floristic characteristics of lechwe habitat, age determination, food habits, habitat use, distribution,condition growth, reproduction, non-social behaviour, social behaviour and organjsation and population status. From data collected it was concluded that, although there was no indication of a drastic population decline, the prevailing high water levels in the system were causing a downward trend in the population by pushing the animals into poorer quality habitat. The decline in the quality of the habitat available to the population was reflected by high juvenile mortality and reduced fecundity of young females. On the basis of the findings of this study a strategy for the conservation and management of lechwe in the Linyanti Swamp is proposed. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1980.

Thesis (MSc. (Veterinary Tropical Diseases, Veterinary Science)--University of Pretoria, 2000. / Also available in print format.

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: John Kappelman. Vita. Includes bibliographical references. Also available from UMI.

To implement sustainable ex-situ management of big ungulate herds such as African Waterbuck (Kobus ellipsiprymnus), one strategy is to place a vasectomized male with females during the sub-optimal season for breeding and subsequently replace him with an intact male during the optimal breeding season. However, information is needed on the effects of vasectomy and the long-term effects on social well-being of individuals used in this "bull-switching" treatment, which is designed to enhance well-being of the whole herd. In this study, behavioral observations were conducted in three periods (pre-treatment, treatment, post-treatment) 2-months in length. Focal individual observations were used to systematically record (a) continuous samples on video (6-min duration; n = 595), (b) instantaneous samples of proximity (n = 951), and (c) field notes of all-occurrences of social interaction (courting and antagonistic). The quantitative and qualitative analyses revealed a significant effect of treatment on three (courtship, escalation, and proximity) out of four measures (deescalation was not affected). Courtship and escalation behaviors increased significantly during the treatment (G2 = 46.35; df=1, P <0.001; z=6.60). The treatment was associated with a significant change in proximity for females (G2 = 17.21; df=1; P <0.001; z=2.31) and other males (G2 =16.10; df=1; P <0.001; z=-3.57). Overall, (1) there was no substantial change with social well-being of the vasectomized male before removal and after reintroduction; (2) the male proximity did not fluctuate significantly with the juvenile males, calves, and other species; and (3) the vasectomized male and the intact male exhibited similar social well-being characteristics. Considering current environmental changes, the treatment did not result in a decline of the social well-being of females and calves, but it did for non-breeding males. Courtship declined in post-treatment, but this was due to the increased percent of pregnant females. During post-treatment, a change in ratio of green grass and supplementary feed pellets possibly affected de-escalation in the context of interspecies interactions. The change of the proximity of the herd was associated with increased heat and use of shaded areas in the pasture. The treatment resulted in a change in relationship with the satellite male and juvenile males in the herd.

A two-year study was made of the blue wildebeest Connochaetes taurinus taurinus in Zululand, Natal. Aspects investigated included age determination methods, growth and condition, reproductive physiology, habitat interactions, and population dynamics. Findings were related to suggested management of the species. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1977.

Frequent reports of damage caused by bushbuck and common duiker browsing on commercially important timber seedlings, and an interest in the potential and feasibility of hunting these two species on State land were the primary factors responsible for the Directorate of Forestry's motivation of this study. The study area at Weza State Forest comprised approximately 21 000 ha of plantations, grasslands and indigenous forests which were considered representative of timbered areas throughout the Natal midlands. Several methods of age determination were investigated and these findings permitted assessments of growth, fecundity and population structure. The physiological condition of both antelope species was examined in relation to age, sex, reproduction and management strategies, and the results discussed in conjunction with mortality patterns. Principal foods of both bushbuck and duiker were determined from rumen analyses while 112 marked animals were regularly monitored to facilitate assessments of habitat selection and levels of spatial and social organisation. of these largely solitary and Estimates of the abundance nocturnal antelope were influenced by local movements in response to the availability of food and cover which varied seasonally and also fluctuated dramatically with forest succession and timber management activities. Although bushbuck and duiker bred throughout the year and had almost identical rates of reproductive performance, different factors were responsible in limiting the sizes of these two populations. All the available evidence gathered in this study indicated that food resources during winter and early spring were inadequate for bushbuck, particularly in 1983 when 33% of the marked population died from starvation and/or exposure. Notable differences in forage utilization and habitat selection inferred little interspecific competition at this time of the year. In contrast, territorial duiker appeared to be susceptible to highly localised habitat modifications (including the availability of food and cover) which occurred throughout the year and resulted from silvicultural and timber harvesting practices. Rumen analyses and quantitative damage assessment surveys revealed that browsing on timber seedlings was usually confined to localised areas during the winter months and was much less severe than had been originally suggested. Conifers were regarded as a starvati~n food and methods of reducing damage to these young trees were recommended for potential problem areas. Both antelope species were considered overabundant at Weza and recommendations for the future management of these populations included the limited utilization of surplus animals, by sport hunting on a sustained yield basis, and methods of manipulating and improving forest habitats. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1986.

Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, December 1999. / Includes bibliographical references. Also available on the Internet.