Multiple warren use by subadult wild rabbits, Oryctolagus cuniculus, and its implications for disease transmission

Abstract

Context Contact rates are a key determinant of disease transmission. Territorial behaviour has generally been considered to limit contact between European rabbits occupying different warrens, particularly during the breeding season. Aims We investigated warren use by subadult rabbits during a period of low population density to determine their potential role in transmission of rabbit haemorrhagic disease and myxomatosis. Methods Subadult rabbits were radio-collared in late summer and relocated twice-weekly for 25 weeks, during which time they grew to adult size and breeding commenced. Key results Rabbits of both sexes used an average of four warrens each on a regular basis, even after older rabbits had commenced breeding. Warrens used by individual rabbits formed a continuously overlapping, irregular array. Subadult rabbits did not belong to separate social groups that utilised separate groups of warrens. Conclusions Subadult or young adult rabbits did not display the same territorial warren fidelity that had been previously described for rabbits. They have potential to carry pathogens between warrens at a landscape scale. Implications Movement of subadult rabbits between warrens is therefore likely to play a critical role in disease transmission, particularly when population density is low. This may help to explain the prevalent seasonality of RHD epizootics in spring when first-born litters of each breeding season typically reach that size.