Abstract: Sexual selection is a frame of reference that attempts to explain exaggerated signaling traits, including acoustic signals between male and female animals. Contemporary studies in the field of sexual selection are focused on the evolution of female mating preferences, with particular emphasis being placed on the good genes models of sexual selection. Here I investigate whether sexual selection is in operation in the acoustic communication system of the field cricket, Gryllus bimacu...
Abstract: African mole-rats (Bathyergidae) exhibit a wide range of social structures ranging from solitary to eusocial. This allows for studies looking at links between sociality and measurable characteristics such as spatial learning and kin-recognition. Furthermore, the existence of species with differing level of sociality allows for comparison between the highly social species and the solitary species. The existence of differences in spatial learning ability and memory between the sexes ...
Abstract: Please read the abstract in the section 00front of this document
Abstract: Please read the abstract in the section 00front of this document
Abstract: In group living species animals commonly compete for limited resources such as food (Darwin 1859). Winning competition for food may be beneficial for an individuals survival or reproductive success (Williams 1966; Clutton-Brock 1988; Metcalfe et al 1995) but conflict with group members may be costly as it typically involves aggression (Huntingford&Turner 1987, Mesterton-Gibbons&Adams 1998). Asymmetries between individuals are predicted to determine the outcome of competition (Mayna...
Abstract: The study set out to determine some of the bioecological relationships of the sable antelope Hippotragus niger niger (Harris, 1838) in the Rhodes Matopos National Park, Rhodesia. The vegetation of the area is divided into seven categories each of which is discussed. The population in the study area (approximately 200) had three major components as follows: the breeding groups, the bachelor male groups and territorial males. The structure of the breeding groups varied seasonally. Ba...
Abstract: Bats inhabiting arid, subtropical environments face diverse challenges related to energy and water balance. First, they may have to conserve water and energy during cool, dry winters when water is scarce and insect availability reduced. Second, during hot summers when air temperature may routinely exceed body temperature, bats may need to avoid both hyperthermia and dehydration. A common response to the energetically challenging winter period in temperate, subtropical and tropical ...
Abstract: The distributional range of the Tete veld rat, Aethomys ineptus, extends from the Limpopo Province in the north through to the south of KwaZulu Natal. The Tete veld rat is a seasonal breeder, with the breeding period confmed to the wet summer months of the year in the Gauteng Province of South Africa. The seasonality of reproduction in the Tete veld rat is confirmed by reproductive tract morphometrics, ovarian histology, plasma progesterone, and oestradiol-17β in females, and test...
Abstract: The aim of this study was to investigate various aspects of the life history of white sharks Carcharodon carcharias at Dyer Island, South Africa, between August 1999 and January 2001. Inter-specific predatory interactions between the white shark and various potential prey species such as the Cape fur seal (Arctocephalus pusillus pusillus), African penguin (Spheniscus demersus), Cape cormorant (Phalacrocorax capensis), bank cormorant (P. neglectus), crown cormorant (P. coronatus) an...
Abstract: Life-history features of terrestrial mammals in the southern African subregion were explored in an attempt to identify the factor(s) that may influence the evolution of common mammalian life-history patterns within this subregion. Allometry and phylogeny were found to underly most of the variation observed in life-history features. Residual variation was considered and age at maturity, gestation period and litter size emerged as additional features influencing life-history patterns...
Abstract: Please read the abstract in the section 00front of this document
Abstract: Researchers use changes in bird community composition to illustrate ecological succession in restoration studies. These studies utilise a variety of methods, some of which may bias their outcomes. Here I used the point and line transect methods to obtain community compositions as well as to estimate total density, species richness and species diversity for bird communities living in a successional sere of coastal dune habitats. The two methods yielded similar estimates of community...
Abstract: Field data were collected and analysed on the feeding and spatial ecology of brown hyaenas living in the Makgadikgadi National Park and in an adjacent Wildlife Management Area where local subsistence pastoralists live. The responses of the pastoralists to a questionnaire designed to document their perceptions of and attitudes towards brown hyaenas and other carnivores that live in the vicinity of their residences, were also analysed. Brown hyaenas living in the Makgadikgadi Nationa...
Abstract: A widely observed pattern in nature is a positive relationship between local abundance and spatial distribution. This study investigates this relationship amongst three taxa namely rodents, millipedes and trees on regenerating and unmined coastal dune forests at Richards Bay, KwaZulu-Natal. No sensible analyses were possible on the rodent data. Both millipedes and trees had a positive relationship between local abundance and distribution (measured as species incidence). Millipedes ...
Abstract: Landscapes are inherently heterogeneous. However, some portions of a landscape are more heterogeneous than others and are therefore not equally suitable for resource extraction by elephants. Elephants have large energy demands to meet and should spend the majority of their time in areas where they are able to forage optimally. Identifying the determinants of home range location and area may therefore provide insight into aspects of landscape utilization by elephants. Using vegetati...