Short-term responses of mammalian carnivores to a sudden collapse of rabbits in Mediterranean Spain

Abstract

The European rabbit ( Oryctolagus cuniculus) is a key prey species for most Mediterranean predators in the Iberian Peninsula, including some endangered species such as the Iberian lynx ( Lynx pardinus). Rabbit populations in the Iberian Peninsula have collapsed since the arrival of rabbit haemorrhagic disease (RHD) in the late 1980s. We studied the dietary and numerical responses of five species of mammalian carnivores to this decline in the Doñana National Park (south-west Spain), where RHD arrived in 1990. Behavioural responses of the Iberian lynx, a rabbit specialist, were also studied through radio-tracking. All carnivores reduced rabbit intake with decreasing rabbit densities immediately after the initial RHD outbreak, though the level of reduction varied among species. Reductions in rabbit consumption were highest for the Eurasian badger ( Meles meles) and the red fox ( Vulpes vulpes), low for the genet ( Genetta genetta) and mongoose ( Herpestes ichneumon), and negligible for the Iberian lynx, thus confirming its strong dependence on rabbits for survival. The Iberian lynx social system was temporarily altered. Female lynxes increased their home range size and no subadult lynxes dispersed in the year following the rabbit crash, causing a temporal local increase of lynx density, which returned to previous values a year after the arrival of RHD. The red fox showed a negative numerical response, reducing its abundance following the rabbit decline. Despite the fact that rabbit consumption was reduced in most carnivores, the role of joint predation is discussed as a factor in the failure of rabbit recovery after this new disease.