Recent negative trends of wild rabbit populations in southern Spain after the arrival of the new variant of the rabbit hemorrhagic disease virus RHDV2

The arrival of a new variant of rabbit haemorrhagic disease virus, known as RHDV2, has recently taken place in the native range of the European rabbit (Oryctolagus cuniculus), a keystone species which has undergone a sharp decline over the last sixty years as a consequence of certain harmful factors. Several works have noted the presence of this new variant in wild rabbit populations, and have in some cases recorded high mortality rates. However, little is known about the response to the arrival of this new virus variant at the population level. The goal of this work is therefore to show recent trends in 26 wild rabbit populations between 2010 (before the outbreak of the disease) and 2014 (after its onset) in two different ecosystems (woodland and agricultural areas), in order to test how their abundances changed over this period, which coincided with the spread of the RHDV2. Overall, our results showed that rabbit abundance was much lower in 2014 than in 2010, and that only 11.5% of the populations monitored proved to have a positive trend, that is, a higher abundance in 2014 than 2010. A positive correlation between rabbit abundance in 2010 and rabbit population trends was obtained, thus suggesting that the impact of the new variant on rabbit abundance is less evident in high density populations. Our results suggest that smaller rabbit populations are those most vulnerable to the outbreak of RHDV 2 and are therefore likely to decline sharply or even become extinct.