abstract
The effect of the disease feline panleucopaenia (FPL) as a primary control measure for feral house cats (Felis catus) on Marion Island (46�'S, 37�'E) is evaluated, suggesting a decrease in density, lowered fecundity and a change in the population age structure. At a low cat density FPL as a biological control measure is probably not effective. The smaller cat population is still reducing the burrowing petrels and this is reflected in a change in the diet of both cats and Antarctic skuas (Catharacta antarctica) and the higher breeding success of petrels in cat free areas. Hunting as a secondary control measure seems possible at a low density and a negative growth rate of cats. Female cats could be removed and density decreased lin-early with time in an intensively hunted area, with hunting success and density showing no statistical relationship.