Some aspects of the Ecology of the Warthog (phacochoerus Aethiopicus Pallas) In Nairobi National Park

Abstract

The thesis presents the data collected during twenty months of field research in Nairobi National Park on the warthog, Phacochoerus aethiopicus Pallas. The warthog is diurnal and passes the night in a burrow. Two of these burrows are described, and the shelter offered by these holes against predators and climatic variation is discussed. The microhabitat is described in terms of climate, vegetation, and soils. - Feeding, drinki ng, scratching, wallowing, resting and toilet behaviour are briefly described. The role of "play" in the development of behavioural display and in the development of motor abilities is discussed. Sequences of social behaviour showing intraspecific aggressions and courtship are given. All these behaviour patterns are then incorporated into an analysis of the diurnal activity pattern. The 'warthog has a strict mating season, between March and May, and the resulting farrowing season occurs in late October or early November. Sexual maturity occurs for females at 17-18 months, and for males somewhat later. The males do not mate until 32 months of age. The fertility rate for the population of warthogs studied was 84.2%, and the average litter size was 1.94. The sex ratio at birth did not differ significantly from unity. The most common grouping is two or more adult females and their young; these groups are often joined by adult males which wander throughout the home ranges of the groups .,. The density of warthogs in the study area was

found to be 14.5 per KM., two estimates of 3.1 and 3.9 warthogs per km ,2 are glven for the whole of Nairobi Park • .•. The concepts of home range and territory are discussed; the average size of the warthog-home range is estimated at 132.9 hectares~ The sex ratio for adult warthogs shifts from unity at birth to 1:1~57 in favour of females. The mortality rate for adults is approximately 15.4% per annum whereas the rate for piglets during the first six months was 48.4% A list of the statistical formulae used in compiling the figures and tables is given in the appendix