Ecology of impala (Aepyceros melampus) and waterbuck (Kobus ellipsiprymnus) in Majete Wildlife Reserve, Malawi

[摘要] ENGLISH ABSTRACT: Protected areas in Africa are under increasing pressure as the human population and their associated activities continue to rise. Habitat loss and fragmentation has led to the isolation of wildlife areas, which are commonly fenced to protect biodiversity and to reduce human-wildlifeconflicts. As fencing impacts ecological processes, intense management is required to conservebiodiversity and prevent habitat degradation in these areas. Effective management and biodiversityconservation strategies depend on a good understanding of the ecological requirements andcharacteristics of dominant species.African Parks is an example of an organization that has overcome many challenges to make anextraordinary contribution to conservation in Africa. After the decimation of most mammals byexcessive poaching in Majete Wildlife Reserve (MWR), Malawi, the park underwent one of thelargest reintroduction programmes on the African continent.Of the 14 species and 2559 animals reintroduced, were 737 impala and 402 waterbuck, both ofwhich are successful breeders and can compete vigorously for resources. Population abundanceand density estimates were determined for a 140km2 section of MWR using distance samplingmethods on drive counts for 14 consecutive months (2013-2014). The data were analyzed in thesoftware programme DISTANCE. Estimates indicated that post-reintroduction impala andwaterbuck populations have increased significantly and displayed a preference for habitatsadjacent to the perennial Shire and Mkulumadzi Rivers in the north-east of the reserve. Populationcontrol strategies needs to be implemented in the near future to curtail the impacts of habitat overutilization by these two species and other ungulates.An apt understanding of species behaviour in specific areas assists managers to developmanagement strategies. Baseline ecology for impala and waterbuck were determined usingbehavioural observations on drive counts, and waterhole counts. Overall, impala and waterbuckhad similar ecology to other populations previously studied. However the impala lambing seasonoccurred marginally earlier and waterbuck calving season peaked in May-June i.e. not in Marchand October as determined by other studies. Furthermore, it was established that impala andwaterbuck adult males utilized waterholes more frequently than females. In addition, impala andwaterbuck males displayed a preference for waterholes according to surrounding vegetation type.Managers should consider these trends when revising the artificial water point management for thereserve.The foraging behaviour of impala and waterbuck were investigated in more detail. Stable isotopeanalysis of dung was used to estimate the graze and browse composition in these two ungulates' diets. It was determined that impala are mixed feeders that readily shift from a high graze contentin the wet summer season to relatively high browse content in the dry winter season. Waterbuckwere typical grazers that were able to utilize browse species in more stressful environmentalconditions. Contrary to a typical dietary overlap occurring in the dry season, impala andwaterbuck have a dietary overlap in the wet, summer months when both species have a high grazespecies content in their diet.MWR management required a better understanding of the ecology of impala and waterbuck postreintroduction to contribute toward management planning. Based on the information gleaned fromthe various studies conducted, both ungulates have successfully established themselves in MWRand their populations have significantly increased and require intensive management to preventenvironmental degradation. Population management strategies should include the translocation ofwildlife from MWR to other parks, as part of a national reintroduction programme in Malawi.

[发布机构] Stellenbosch University