Game restocking and the introduction of sarcoptic mange in wild rabbit in north-eastern Spain

The European wild rabbit Oryctolagus cuniculus has been recently reclassified as Near Threatened in its natural range in the Red List of Endangered Species by the IUCN, and a huge conservation effort is being undertaken in Spain for this keystone species. Restocking is a frequent measure for wild rabbit population reinforcements and it is also part of predator conservation programmes. However, it can have a negative influence on the resident rabbit population when it is not carried out carefully. In our work, using a model selection procedure based on a theoretic information approach, we analyze which factors favor the presence of sarcoptic mange in some wild rabbit populations in Catalonia (north-eastern Spain), as well as the trend of rabbit abundance in affected and non-affected hunting estates. Presence of mange depends on animal abundance and on restocking numbers (22.09%). From the mean rabbit abundance (30 rabbits hunted km-2) and the mean restocking rate (18 rabbits km-2), the probability of being affected increased in nearly 5% when the restocking rate increased in one unit. Rabbit abundance (2001-2007) depends on the presence of mange and on the effect of the year (23.86%), and clearly declined in the hunting estates with mange, whereas abundance is maintained in mange-free zones. Our results indicate that a sanitary control is necessary when restocking wild rabbit populations. Furthermore, restocking is shown to be a potential way of introducing pathogens to resident populations, especially under conditions of high density. © 2010 The Authors. Animal Conservation © 2010 The Zoological Society of London.