Published online by Cambridge University Press: 24 August 2009
The varying reasons are outlined for needing to control the movements or otherwise manage a wide range of African animal wildlife species by means of fencing. In all cases there is an underlying conflict of interest between people and animals — principally the larger mammals. Fencing is seen as the most powerful tool in this process of land-use division, and high expectations of fences are held by people who are adversely affected by wildlife activities and similarly by many conservationists. To date the main determinants in the siting and construction of fences have been political pressure or the availability of funds; wildlife fencing is perhaps the only factor having a substantial influence on ecosystems and animal populations that has remained virtually devoid of any serious input of ecological knowledge, of systematic investigation, or of environmental legislation.
The wild species requiring management are many and varied in individual size, group size, and dispersal patterns; they also exhibit an array of special behaviours when confronted with a barrier. This means that any barrier will come under very variable levels and types of challenge, and that the effects of it on the biology of both target and non-target species must be carefully considered.
Research on the behaviour of animals at fences has been limited, being mostly confined to domestic species or non-African wildlife. Certainly, very little systematic investigation has been carried out to determine whether fences have achieved their objectives or been economically justified, and to what extent they have caused environmental side-effects on the population dynamics of animals or the disturbance of plant communities.
Current evidence suggests that electric or power fences are an increasingly efficient way of managing wild mammals and that fencing programmes should become more deflecting than encircling. Fences create ‘hard edges’ between dissimilar forms of land-use and cause long-term inflexibility that limits planning and forecloses options. As the pressure for land becomes more and more acute, the control of wildlife with the help of fences needs to develop into a specialized field of its own, based on sounder ecological, sociological, and economic, principles than hitherto, within the expanding scope of adaptive wildlife management.