The value of a long-term bushmeat market dataset as an indicator of system dynamics

Data on prices and quantities of wildlife on sale in markets are increasingly being used as indicators of the sustainability of bushmeat hunting, being relatively easy to collect. However, it is not clear how much can actually be inferred from trends in such data. This study analyses changes in price, quantity, method of capture and kill location of bushmeat species entering the Atwemonom bushmeat market in the city of Kumasi (Ghana) over the period 1987-2002, using data collected by an official of the Ghana Wildlife Department. The analysis was confined to the seven most commonly traded species and to the open season only, in order to maximize the reliability of the data. Over the period, there was an increase in real bushmeat prices, in the proportion of animals killed by means other than guns and the trade made up by grasscutters (Thryonomys swinderianus). A higher proportion of animals originated from distant areas, rather than from villages close to Kumasi. These trends are compatible both with depletion of the bushmeat resource and with an economically rational response by hunters to increasing prices. The analysis highlights both the utility and the limitations of detailed long-term market data as a tool for assessing the sustainability of wildlife hunting. Data on the origin of animals sold in the market and the gear type are necessary but not sufficient for understanding the drivers of changes in price and quantity of species on sale in markets; without complementary detailed local data on hunter behaviour, market data are of little value.