The roan antelope (Hippotragus equinus, Desmarest 1804), its ecology in the Waterberg Plateau Park

[摘要] ENGLISH ABSTRACT: This study was undertaken in the Waterberg Plateau Park innorthern Namibia. Field work took place between January 1988and September 1989; however relevant information collectedsince, has been included. The roan antelope population in the reserve stems from re introduced animals. A total of 93 were brought in between 1975 and 1981. By 1984 the population peaked at 275 individuals. 186 roan have since been captured and, sold.The main objective of the study was to develop a betterunderstanding of the management requirements for thispopulation of rare antelope.Approximately one-fifth (32 individuals) of the populationwas marked with eartags or plastic collars or both. Fiveanimals were radio-collared. This is the first detailedstudy of. roan ante lope in such a large study area (40 000ha), with such a large population and so many markedindividuals.Chapter 3 deals with population dynamics. It is believed that the entire population was accurately counted, aged andsexed. The adult sex ratio was skewed in favour of females,despite the absence of predators large enough to killadults.The majority of calves were born during the wet season, fromthe end of August to March. A positive relationship betweenearly season rainfall and the calf crop in the subsequentyear was found. The ratio of juveniles per 100 adult femalesaveraged 4.1 over seven years.Recorded mortality was too small to identify significantfactors.Two deterministic population models were developed forexploratory simulations and are presented in Chapter 4. Bothsimulations were fairly successful, giving good correlationswith the actual counts.Nutrition is covered in Chapter 5. Simple nutrient budgetsrevealed that protein and phosphate requirements wereprobably not met in the dry season. Calculations based onhand selected forage samples and nutrient requirements ofcattle, show that adult roan obtained 15-28% of their crudeprotein requirements and approximately 10% of the phosphatein the dry season.The social system of the roan is described in Chapter 6.Four different clans were recognized, each with a distincthome range. The breeding groups in each clan were unstable,splitting up and rejoining at random.Adult males exhibited territoriality during the breedingseason, which is in contrast to most other studies whereharem groups were observed. Outside the breeding season,dominant males rejoined bachelor groups or remainedsolitary.Home range size and configuration were described usingdifferent methods. Home ranges averaged 4800 ha for two clans _'0.-_.and the territory size of one male was estimated to be 1200ha within a much bigger home range. Distinct wet - and_dry - season ranges could be distinguished.Habitat selection is discussed, and was determined primarilyby feeding requirements. Forage quality was identified asthe major limiting factor and thus the primary determinantof habitat use.In Chapter 7 management recommendations and researchproposals are made to ensure sustainable utilisation, by both live capture and game viewing.

[发布机构] Stellenbosch University