A MODEL ILLUSTRATING THE CHANGES IN FOREST ELEPHANT NUMBERS CAUSED BY POACHING

A geographic information system (GIS) was used to analyse field data on the abundance of elephant dung-piles. For each country, the GIS was used to create contours representing distances from roads or rivers. The area of forest between each contour was then calculated. The curvilinear relationships between dung-pile density and distance to the nearest road or village were then used to calculate the numbers of dung-piles between contours and the total for each country. Comparisons between undisturbed and heavily poached elephant populations suggest that the total forest elephant population in central Africa has been reduced by about 44% as a result of ivory poaching. Forest elephants may be more vulnerable to poaching than previously thought because, for example, two-thirds of Congo's elephants live within two days' walk of a road or navigable river.