The most common method of culling impala (Aepyceros melampus) and many other antelope species in Africa was evaluated from a welfare point of view. The culling of 856 impala from 401 herds was observed and recorded in the Mkuzi Game Reserve, South Africa. Ninety-three per cent of animals were killed instantaneously by the first shot. Results indicated that herd size and composition, distance of herd from hunting vehicle and shot number all have a bearing on the number of animals wounded and missed. It is concluded that the culling of free-ranging impala by night-hunting in the manner described is a satisfactory method on welfare grounds, although a number of recommendations are made which might render the culling process more humane. It is argued that economic and welfare considerations are not necessarily in conflict, and long-term efficiency is likely to be enhanced by addressing both simultaneously.

The movement of African ungulates between habitats is determined by diverse factors including forage composition, availability and quality, water availability, topography, the catenary level and the effect of fire on vegetation. We assessed how grass flushes, following dry-season fires, and availability of water influenced seasonal movements of hartebeest, impala, warthog, white rhino, wildebeest and zebra in Ithala Game Reserve, a fenced reserve in South Africa. Over a 6-d period each month for 4 y, road transects covering a representative sample of the reserve's different vegetation types, and 23% of the reserve's total area, were carried out. We recorded the species, number, sex and age class of herbivores, obtaining 8742 records (total herbivores sighted = 47055), and obtained positional data on sightings over the last 2 y of the study. Using a GIS-based approach, we determined that ruminant, but not non-ruminants, were significantly attracted to dry-season grass flushes, and that presence or absence of such flushes significantly affected their mean distance to water and hence seasonal movements on the catena.

Resource depletion and associated increases in interspecific competition are likely to influence differential habitat usage amongst a guild. We tested some prominent theoretical concepts using observed differences in seasonal habitat use amongst the savanna browser guild (elephant, giraffe, impala, kudu and nyala) in Hluhluwe-iMfolozi Park, South Africa. Herbivore locations (n = 3108) were recorded over 2 y using repeated road transects and, for elephant, GPS collars (187 254 downloads). Densities were calculated using a novel GIS approach designed to be a cost-effective method for annual censuses, but also able to cope with abrupt changes in visibility. Selectivity for (Manly's α) vegetation types, and overlap (Schoener's index) in vegetation type usage were calculated. Resource depletion in the dry season resulted in all members of the guild increasing selectivity for vegetation types (sum of absolute values away from the neutral value for Manly's alpha for the guild: dry seasons 3.97, 5.16; corresponding wet seasons 3.12, 3.68), but decreasing interspecific overlap (80% of Schoener's indices lower in dry season versus wet season). These effects were more marked over the second, more severe, dry season. We found support for the niche overlap hypothesis and the niche compression hypothesis. The Jarman–Bell principle was generally supported, although unexpectedly during the severe dry season elephant showed the most selectivity for vegetation type. The greater the resource depletion, the more relevant interspecific differences in habitat usage become in relation to the differential impacts of guild members.

To clarify the potential influence of different browsers in the same guild on woody vegetation, dietary overlap and separation between elephant, giraffe, kudu, nyala and impala was assessed in Hluhluwe-iMfolozi Park, South Africa. Woody species browsed, browsing heights, plant-parts browsed and browsing versus grazing were recorded over 2 y by direct observation. We obtained 3068 browse records. Niche breadth (Levins' measure) and overlap (Schoener's index) in species browsed and browsing heights were calculated. Annual and seasonal differences in these measurements, plant-part use and browsing versus grazing were assessed. Elephant utilized the largest number (n = 78) of different woody plant species. Overlap in species browsed was lower between elephant and other browsers than amongst the latter. Seasonal rainfall influenced the range of woody plants utilized, niche breadth in terms of species browsed and browsing versus grazing. Marked resource depletion caused elephant, contrary to theoretical predictions, to narrow niche breadth in terms of species browsed. However, resource depletion rarely had a significant effect on interspecific overlap in species browsed or overlap in browsing heights, on actual browsing heights or plant-parts utilized. A small suite (n = 8) of woody species formed the core diet of all guild members, implying the potential for synergistic impacts by guild members on these species and for competition between populations of different guild members.

The previously unknown life-cycle of Cooperia fuelleborni, parasitic in impala, is described. The morphology of the developmental stages are compared to those of other Cooperia spp. The similarity between C. fuelleborni and C. curticei is discussed as well as the differences between those two species. The morphological studies showed that C. fuelleborni is closely related to C. curticei of sheep, but also has some affinity with the cattle parasite C. punctata and C. oncophora.

Forests are being converted to grasslands and croplands across Africa and natural regeneration of forests is typically poor. In Serengeti National Park, Tanzania, the savanna tree species Acacia polyacantha established in riparian grasslands and forest trees subsequently established within these stands. We examined the conditions for establishment of: (1) A. polyacantha and (2) riparian (non-Acacia) forests. Fire was excluded from three grassland areas for 5 y allowing A. polyacantha to establish during 1999 when dry-season rainfall was high. The seedlings of forest tree species did not establish in grasslands, but were found in large A. polyacantha stands (> 0.3 ha) with reduced grass cover (< 10%), higher cover of herbs (> 80%) and thorny shrubs (> 90%). Seeding survival was high in large stands (0.87 y−1), but declined in artificial canopy gaps due to the ingrowth of grasses (0.21 y−1) and subsequent fires (0.07 y−1). Shrub removal also reduced seedling survival (0.46 y−1) due to browsing by antelope. We propose that: (1) A. polyacantha establishes in pulses perhaps as infrequently as twice per century, and (2) riparian forests in Serengeti have established via facilitation under larger stands where shade excludes grass, and therefore fires and thorny shrubs exclude browsers.

Resource partitioning between elephant, giraffe, kudu and impala was assessed. This was to address concerns that elephant population increase adversely affects other species through depleting their food in key areas close to permanent water. Resources considered were woody species browsed, height browsed and plant parts browsed. Animals were observed as they browsed and the plant species, browsing heights and plant parts browsed were recorded. Observations were made over 1 y and the data were divided between wet and dry season. Schoener's index of resource use overlap was calculated for plant species, browsing heights and plant parts eaten and differences in overlap between wet and dry season were tested. Levin's measure of niche breadth in plant species utilized by the different browsers was calculated. Woody species identity was the main separator between food resources that elephant used and those giraffe, impala and kudu used. Giraffe, kudu and impala mainly browsed the same species and plant parts but browsed at different heights. There was no difference in resource use overlap between seasons with different resource availability. Since elephant browsed different woody species from those browsed by the others, it is unlikely that the increasing elephant population will deplete food resources for the other browsers.

Cheetah Acinonyx jubatus home-range size and habitat use were analysed using radio-tracking data collected in the southern district of the Kruger National Park (KNP) between 1987 and 1990. Meaningful estimates of home-range size, using the 95% minimum convex polygon method, were 126 km2 for a three-male cheetah coalition, 195 km2 for a solitary male, and 150 km2 and 171 km2 for two female cheetahs. Although cheetahs used all habitats according to their availability, they did show a preference for open savanna habitat because their core or total home ranges centred on these habitats. Female cheetahs used denser woodland habitat more frequently than males, as they seemed to be influenced by the distribution of their main prey, impala Aepyceros melampus, which also preferred denser woodland habitat.