Natural & Applied Sciences

Natural & Applied Sciences Research Papers/Topics

Structure, development and composition of the integument of the southern right whale, Eubalaena australis

Abstract: The general architecture of the skin of the southern right whale, Eubalaena australis, is comparable to that described for other cetacean species. As found in bowhead whales, Balaena mysticetus, of the same family, southern right whales possess an acanthotic epidermis and a notably thick hypodermis. Epidermal rods and extensive papillomatosis support these unique characteristics. A "fat-free" reticular dermis makes the integument of southern right whales more like that of odontocet...

Environmental factors influencing the distribution of southern right whales (Eubalaena australis) on the South African coast

Abstract: Distributional data from 32 years of aerial surveys of southern right whales (Eubalaena australis) along the south coast of South Africa were investigated using GIS, over a variety of spatial and temporal scales to test whether their discontinuous yet predictable distribution is related to environmental characteristics. Most whales were found in areas that provided reasonable protection from open ocean swell and seasonal winds as well as having sedimentary floors with gentle slopes...

Cheetah Acinonyx jubatus ecology in the Kruger National Park : a comparison with other studies across the grassland-woodland gradient in African savannas

Abstract: The objectives of this study were(1) to analyse a data-set on cheetah home range size, habitat utilisation, prey selection and hunting behaviour in the Kruger National Park (KNP), and (2) conduct a comparative study on the above aspects of cheetah ecology across a variety of African savanna ecosystems. Cheetah home range sizes in the KNP for territorial male cheetahs were 173 km2, 438 km2 for a nomadic male cheetah coalition, and 193 km2 and 179 km2 for two female cheetahs. Cheetah...

Elephants in the Waterberg : impacts on woody vegetation by breeding groups compared with bachelors

Abstract: In May 1994 IFAW funded the relocation of 50 elephants from the Kruger National Park to Welgevonden Private Game Reserve in the Northern Province, South Africa. Impact by the elephants on the vegetation of this reserve has since become a concern. The aim of this study was to quantify impact by the elephants on the woody vegetation by investigating vegetation and habitat use by elephant bachelor and breeding groups. This was determined by comparing resource use between sexes within ...

The distribution and abundance of macro-invertebrates in the major vegetation communities of Marion Island and the impact of alien species

Abstract: In this study macro-invertebrates were sampled quantitatively in 10 lowland vegetation communities on Marion Island over a one-year period commencing in May 1996 as part of a larger investigation into the distribution, abundance and species energy use of invertebrates across an altitudinal transect on Marion Island. The data collected for this particular study were used to investigate the habitat specificity and seasonality of the macro-invertebrates, as well as the impact of alien...

Avian nectarivory and pollination in Aloe marlothii Berger : interactions between bird communities and a winter-flowering succulent

Abstract: Aloe marlothii is a winter-flowering succulent that is widespread in the savanna biome of northern and north-eastern South Africa. Plants grow up to 8 m in height and are commonly found on rocky north-facing slopes. Nectar production occurs through a 24 h period with flowers producing copious amounts (c. 250 µl) of dilute nectar (c. 12%). This abundant nectar supply, that is available for a 5-10 week period during June-August, is utilised by numerous opportunistic avian nectarivor...

The ecology of the leopard (Panthera Pardus) in the Waterberg

Abstract: Although the opportunistic feeding habits of leopards were evident in this study, scat analysis showed that ungulates were by far the predominant food, with impala being the most frequent item. The fact that cattle calves were only taken up to ± 100 days old, emphasize the relevance of a proper stock management program to prevent stock losses. In addition, where such measures were impractical, temporary physical barriers such as electric fencing showed potential for application. M...

The feeding response of white-bellied sunbirds (Cinnyris [Nectarinia] talatala) to sugar concentration and viscosity of artificial nectar

Abstract: Plant nectar is a simple food and is easily digested by many different species of pollinators. Many compounds make up the composition of floral nectars, but the most abundant are sugars, generally dominated by sucrose and the hexoses, glucose and fructose. Nectar sugars have been measured for many plant species visited by hummingbirds, sunbirds and other passerines, revealing a range of concentrations. The nectars of passerine-pollinated flowers are generally dilute compared to tho...

Determinants of protected area boundary crossings by savannah elephants, Loxodonta africana

Abstract: When elephants leave primary protected areas (PPAs), such as national parks and game reserves, they may come into conflict with people residing on the adjoining land. In this study, I attempted to determine why African savannah elephants leave the PPAs in which they were collared. To accomplish this, I used telemetry locations of collared elephants in PPAs throughout southern Africa and investigated whether a range of intrinsic and extrinsic variables could explain why elephants cr...

An Atlas of hair from southern African mammal species with reference to its taxonomic and ecological significance

Abstract: ENGLISH: This thesis is a study of the microstructure of hair of southern African mammals, in particular of the Carnivora. It serves to fill a gap in knowledge of hair studies from this region, and points to the use of these studies in various fields. A major portion of the work is a hair atlas of southern African Carnivora, in which micrographs and coloured plates of hairs are presented with locality data and a descriptive text for each species. Although the findings of the atlas ...

Molecular and morphological assessment of invasive, inland Rattus (Rodentia: Muridae) congenerics in South Africa and their reservoir host potential with respect to Helicobacter and Bartonell

Abstract: Invasive species are generally problematic where they occur, especially in terms of ecology, economy and disease. Members of the genus Rattus Fischer, 1803 particularly, are known as one of the most destructive invasive species to date since they cause widespread damage on terrestrial and island ecosystems. Two Rattus species have historically been reported as invasive species in South Africa, Rattus rattus Linnaeus, 1758, which has a widespread distribution throughout the country ...

The functional significance of grooming behaviour in higher primates : the case of free-living chimpanzees

Abstract: As a contribution to the existing knowledge of grooming in primates five and a half years of grooming data were examined from a group of free-living chimpanzees (Pan troglodytes) in the Budongo Forest, Uganda, to investigate various functional significances of grooming behaviour within the context of social reinforcement. The fission–fusion social structure of chimpanzees results in group members not moving around as a single unit, but forming temporary units as the need arises. ...

The circadian system of African mole-rats : behavioural activity rhythms and early gene expression ( c-fos ) in the suprachiasmatic nucleus

Abstract: Mole-rats from the family Bathyergidae are endemic to Africa, this family exhibits a continuum of sociality, comprising both solitary and social species. Sociality is related to the degree of aridity and the distribution of the underground food resource. All the members of the bathyergid family are strictly subterranean, and occur in a niche which is devoid of light cues and thermally buffered from ambient and surface extremes. Since vision is redundant in a lightless environment, ...


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