Population Dynamics of the Elephants in the Kasungu National Park, Malawi

Abstract

By using an elephant recognition file that was compiled during the study, data on group structures were obtained. A photogrammetric method was used to obtain data on the age-structure of the separate groups and the population as a whole. The age-structure is that of a young, healthy and rapidly increasing population. Peaks and troughs in the age-structure are related to local rainfall, which indirectly affects the conception-rate and age-specific mortality. The mean calving interval estimated by means of the photogrammetric device is 3.9 years, while the age of first conception can be as low as 7 years. A sex specific difference in the survival rate acts in favour of the female. In mature elephants, human interference such as selective shooting by poachers and the crop control unit also promotes a departure from a sex ratio of unity. The influence of human interference on the reproductive output of the population is discussed. The mean annual mortality rate is estimated as 7.7% from the survival curve of the population. This figure is high compared with figures on this parameter from other populations, which is explained by human activity.