Relative abundance wild rabbit (Oryctolagus cuniculus) and red fox (Vulpes vulpes) after rabbit haemorrhagic disease (RHD) in the Central Ebro Bassin in Northeastern Spain

The relative abundance of red fox (Vulpes vulpes) and wild rabbit (Oryctolagus cuniculus) was studied by nightspotting in the Ebro Bassin, Spain, where rabbit haemorrhagic disease is enzootic in free-living rabbit populations. From 1992 to 1997, 500 nightcounts were performed at 13 localities, and the results were converted into relative abundance indexes (Tabl. 1, 2). Local changes in yearly red fox and rabbit abundance were detected. For the rabbit, even yearly differences in abundance on a regional scale were found. None of the two species shows a generalized trend of population growth or decrease (Fig.). Possible causes of local abundance changes, and the ecological consequences of rabbit decline are discussed.