Ecology of the bushpig Potamochoerus porcus Linn. 1758 in the Cape Province, South Africa

[摘要] ENGLISH ABSTRACT:Bushpig sociology, energetics, reproduction and population dynamics werestudied over an 8-year period in the Cape Province, South Africa. Thesocial organization was found to be strikingly different from that knownfrom other suid species. The basic social unit is a unimaternal familygroup, occupying a resource-based territority, with a monogamous matingsystem. This form of social organisation is related to the dispersednature of food resources, to which it provides exclusive access. It isreminiscent of canid social systems. Agonistic behaviour, communicationand maternal behaviour were studied as the opportunity arose. Theaverage home range size was 7,2 kmª, ranging from 3,8 to 10.1 kmª. Homeranges were often traversed within 1-4 days, as part of territorypatrolling. The average diel ranging distance was 3 km. Bushpig wereactive during both night and day and exhibited a basic bimodal rhythm.The main phase of intensive foraging occurred from before dusk tomidnight, with a secondary activity peak after dawn. Activity scheduleswere geared to avoid extreme ambient temperatures. Temperatureregulation and water use were investigated, with particular reference tothermoregulatory behaviour (nest building). pelage characteristics, bodycore temperature dynamics, thermoneutral zones and resting metabolicrates. The thermoneutral zone for 10 kg bushpig juveniles was estimatedto lie between 13° and 30°C and that for adults between 8° and 25°C.Foraging behaviour, diet and its nutritient content were investigated.Regional differences in the nutritional quality of bushpig diets in theEastern and Southern Cape were associated with the predominance ofnutrient-rich and nutrient-poor substrates respectively. These in turnwere reflected by divergent life history features in the populationsfrom the two regions. Patterns of growth and energy storage weredescribed and the value of various parameters (e.g. mass to size ratio,fat depositions, blood composition) to evaluate condition wasinvestigated. In studying reproductive biology, sexual maturation,female reproductive cycles, prenatal litter statistics, foetaldevelopment, 1actation, breeding seasonality and reproductive turnoverwere the main aspects addressed. The role of food quality, bodycondition and social status in determining reproductive success wasdiscussed. Bushpig population density estimates in the Southern Caperanged between 0,3 and 0,5 animals/kmª• The dynamics of Southern andEastern Cape populations were found to differ. The differences areconsistent with the hypothesis that social organisation is determined bythe distribution and availability of foodwhile diet quality shapeslife history tactics. A life history model was developed which linksedaphoclimatic environmental conditions with diet quality, metabolicturnover rate and, ultimately, life history features. In the concludingchapter some of the managerial implications of the research findings arediscussed.

[发布机构] Stellenbosch University