Studies commenced in 2001 to determine whether conventional rabbit control programs affected the subsequent impact of rabbit haemorrhagic disease (RHD). Eight sites were chosen in semi-arid and moist temperate areas. At each site, higher-density populations were paired with nearby populations where density was reduced by chemical/mechanical rabbit control. Rabbits were classified as having antibodies to virulent RHD, to an RHD-like non-pathogenic calicivirus (benign CV) or no antibodies (sero-negative). The prevalence of RHD antibodies was similar across regions but there were more sero-negative rabbits in semi-arid (43%-54%) than temperate areas (19%) and fewer rabbits with benign CV antibodies in semi-arid (6-10%) than temperate areas (38%). This effect was evident in both juvenile and adult rabbits. Rabbit control programs reduced rabbit density, increasing the proportion of sero-negative rabbits and reducing RHD sero-prevalence in juvenile rabbits (<1300g) but not in adults (³1300g). Hence, rabbit control slowed the circulation of RHD in juvenile rabbits but ultimately a similar proportion of rabbits were infected. Because primary infection occurs at a later age and mortality is higher in older juveniles, rabbit control does not reduce the impact of RHD. We found no effect of rabbit control on the interaction between RHD and benign CV that could be exploited to improve the effectiveness of rabbit control.
|Author||Mutze, G., McPhee, S., Butler, K., Backhouse, K., Kovaliski, J. and Capucci, L.|
|Secondary title||13th Australasian Vertebrate Pest Conference|
|Place published||Wellington, NZ|
|Institution||SA Annimal and Plant Control Commission|
|Control method||Biological Control|
|Region||Australia - national|