Observations on the effectiveness of warren destruction as a method of rabbit control in a semi-arid environment.

The effectiveness of warren ripping as a method for controlling rabbits in a semi-arid environment was tested on a 3000 ha site at Kinchega National Park in western New South Wales. Estimates of rabbit numbers made during the study showed that the immediate effect of warren ripping was to reduce the rabbit population by about 65%. The longer term effect was to stabilise numbers at a relatively low level. The only warrens active 14 months after being ripped were those which gained new burrow entrances within two months of being destroyed. Re-opening rate of warrens was greatest for large limestone warrens where 90% of ripped warrens were again active after two months. Less than 30% of all sandy warrens became active again. Within each re-opened warren, the number of active entrances increased slowly but 14 months after being destroyed they had still not reached their original size.