Ecological costs of feral predator control: foxes and rabbits

We used a predator removal experiment to examine the role of red fox (Vulpes vulpes) predation in suppressing rabbit (Oryctolagus cuniculus) population growth in Namadgi National Park in southeastern Australia. At 2 sites, fox abundance was reduced with a 1080 poisoning campaign maintained over 18 months. The responses of rabbit populations in these fox-reduced sites were compared to 2 other sites where fox populations remained intact. In the 2 removal sites, rabbit populations grew to 6.5 and 12.0 times their initial population size within 18 months. In the untreated sites, rabbit populations showed very small population increases over the same period. The experiment demonstrated that 1 introduced pest species suppressed the population growth of another pest species. As fox removal was initially planned to protect native fauna threatened by fox predation, the response of the rabbits represents a serious ecological cost of fox control.