Remains of prey of black-backed jackal Canis mesomelas from 13 jackal middens situated within 25 m of the beach, which provides the most regular source of food, and one 1.3 km inland in the Skeleton Coast Park, Namibia, were examined. Middens accumulate on small sand hummocks which provide shelter from prevailing harsh environmental conditions. Canis mesomelas is shown to rely on marine resources. A total of 30 taxa was recorded. Birds were the most common prey individuals represented in the combined samples (68%), followed by mammals (17%) and fish (15%). One invertebrate was recorded. At the inland site, which is located at a colony of whitebreasted cormorants Phalacrocorax carbo, this species alone formed 78% of the total individuals. Surveys were conducted to determine the extent to which C. mesomelas is unselective in scavenging beached seabird carcasses and the results were compared with data on roosting habits. There was good correlation between both these sets of data and the contents of the jackal middens, thereby indicating that C. mesomelas is unselective in its foraging/scavenging. The drop in the jackass penguin population was also evident when middens of different ages were compared. It was shown that the data from jackal middens provide an index of seabird mortality which reflects changes in the oceanic and climatic conditions which affect fish populations. Regular monitoring of jackal middens may provide an easily accessible source of information on long- and short-term changes in fish stocks.