The inter- and intraspecific taxonomy of the genus Lepus is highly controversial. Since these animals play an important ecological role as prey species, their conservation is of high priority. A prerequisite for adequate management strategies is the precise knowledge of taxonomic borders and geographic distributions of the taxa in question. Especially in African hares the clear delimitations of the species and subspecies are still unresolved. In an attempt to obtain a clearer understanding of the evolutionary history, the phylogenetic relationships and the detection of conservation relevant units in African hares, a molecular investigation using mitochondrial DNA sequence data and information from six microsatellite loci was initiated. In this study, the phylogenetic analyses of DNA sequence data of the mitochondrial control region and the cytochrome b gene identified 2 major maternal lineages within South African hares that were further subdivided into two clusters each. The nuclear genetic structure revealed by six dedicated microsatellite loci confirmed this subdivision. While the mitochondrial diversity was characterized by high sequence divergences and haplotype diversities, the nuclear variation seemed more moderate with relatively low FST and RST values. Using the information content of the six microsatellite loci developed for this project, the results of assignment tests strongly supported the validity of the four genetic lineages. The levels of of cytochrome b sequence divergences among the four clusters suggested that they may warrant distinct species status (applying the phylogenetic species concept). The data are suggestive of two species groups consisting of two sister species each: A "saxatilis" group with Lepus saxatilis sensu stricto and another species (possibly L. victoriae), and a "capensis" group with L. capensis s. str. and another, yet to be described species. Applying a molecular clock for cytochrome b, the historical dates for the separation of the South African hares from European outgroup species and the split between the two South African species groups were calculated as 4.84 and 3.45 million years ago, respectively. The divergence dates between the sister species was 1.09-1.45 million years ago. Following the biological species concept, the two major clades represent two species: L. saxatilis sensu lata and L. capensis s. I. , that are both subdivided into two geographically separated phylogroups, one in the southern parts of the country and one in the northern. These intraspecific lineages meet the criteria of evolutionarily significant units and should be considered separately in conservation actions. The evolutionary history of scrub and Cape hares in South Africa has been influenced mainly by contiguous range expansions and sudden population size expansions during the Pleistocene climate changes. / Thesis (PhD (Zoology))--University of Pretoria, 2002. / Zoology and Entomology / unrestricted

Springhare are large, bipedal, nocturnal, herbivorous, burrowing rodents that are found in arid and semi-arid parts of southern and eastern Africa. In this thesis I examine the general ecology, biology and physiology of these animals in the Eastern Cape Province of South Africa. An investigation of their distribution and activity in the study site showed that springhare exhibit a preference for flat, open, recently disturbed habitat that is dominated by the grass Cynodon dactylon and the sedge Cyperus esculentus. These two species constitute a major proportion of their diet. The impact of spring hare on chicory and grazing is also discussed. Nightly activity generally peaks soon after dark and decreases in the 2-4 hour period before sunrise. This pattern is, however, modified by moonlight. Springhare typically respond to moonlight by reducing aboveground activity, shifting their activity to dark moonless periods of the night, and by reducing their use of open space. Contrary to earlier reports, springhare utilise several different burrow systems spread over large areas. They regularly change burrow systems and seldom spend more than a few consecutive days in each. Springhare do not appear to defend territories but recently used burrows appear to be avoided by conspecifics. Males and females on average use a similar number of burrows, scattered over similar sized areas. Burrows are shown to provide a stable microclimate of moderate temperature and high humidity throughout the year. Reproduction is continuous and there is no synchronised breeding season. The ability to reproduce throughout the year is attributed primarily to their ability to utilise subterranean food stores. The overall reproductive strategy of springhare (a single young with long gestation and weaning) is unusual for a mammal of this size but may be linked to low levels of adult and juvenile mortality. Physiologically, springhare are reasonably well adapted to life in hot, arid environments. They produce a concentrated urine, exhibit a high tolerance to dehydration, are good osmoregulators capable of maintaining plasma volume, osmolality and ion balance over long periods of water deprivation, and are able to produce dry faeces. They are also good thermoregulators at low ambient temperatures, which are usually encountered at night, but are poor thermoregulators at high ambient temperatures, which they avoid behaviourally.