Eight Cape fur seal breeding colonies are found on the Namibian mainland, including three of the largest in southern Africa (David & Rand 1986, David 1987), at which hundreds of thousands of seals are present during the pupping period. Brown hyenas and black-backed jackals occur along the entire coastal Namib Desert and therefore have access to all of these seal colonies. All but one mainland Cape fur seal breeding colonies were established during the past 60 years (Rand 1956, Best 1973, Best & Shaughnessy 1979, David 1987), whereas both terrestrial carnivores historically have occurred along the coast before this time, mainly scavenging carrion (e.g. seals, seabirds, fish and crustaceans) washed up on beaches (Gaerdes 1977). The occurrence of these carnivores might have prevented the settlement of seals in the past, but other, more important factors seems to have influenced the recent establishment of mainland colonies. One explanation is an increasing population size and the lack of space on adjacent islands, which has forced the seals to settle on the mainland opposite such islands (David 1987). Initially mainly non-breeding seals were found in accumulations along the coast and colony growth was possibly subdued due to predation on the few newborn pups (Shaughnessy 1987, Oosthuizen et al. 1997), easily possible due to the lack of anti-predator behaviour. With a further increase in seal population size, the successful establishment of breeding colonies has become possible despite this predation pressure and has led to the present occurrence of large and successful colonies. This development raises questions about how the seals deal with previously unknown terrestrial predators, how these predators use this permanent and concentrated food source and whether these predators influence the population dynamics of the seal colonies.