Rhinos declined in all areas at rates ranging from -0.99 to -0.24, but elephants increased in some areas due to local immigration. (5) Sightings of rhinos and elephants changed at different rates in each area of Luangwa Valley. These declines arose from illegal activity as most skulls had their trophies removed. (4) The overall rates of decline of rhinos and elephants were -0.63 and -0.12 during 1979-85, following rapid increases in the price of rhino horn and ivory on world markets. Sightings of rhinos and elephants were negatively correlated in different areas of Luangwa Valley during this period. (3) Elephants increased at an instantaneous annual rate of +0.06 from 1947 to 1969, causing the `elephant problem' of the 1960s and 1970s. Sightings were analysed with log-linear models and population trends for elephants and rhinos so derived compared favourably with accurate methods of counting both species. (2) Sightings and captures by law enforcement patrols were used to monitor (i) changes in rhino and elephant numbers during 1947-85 (ii) their motivation and success at capturing offenders involved in illegal activity during 1979-85 and (iii) the distribution of illegal activity in relation to patrol effort and the abundance of rhinos and elephants during 1979-85.
This study documents the demise of both species in the Luangwa Valley, Zambia. (1) At the start of the 1980s, conservationists in Africa gave a high priority to protecting the largest remaining populations of black rhinos and elephants from illegal exploitation.