Rabbits are pests in many areas of New Zealand because they have a negative impact on agricultural production and conservation values. The production impact is predominantly on pastoral enterprises where rabbits reduce profitability of wool growing by a scarcity of quantitative information on the extent of these impacts and how they vary with rabbit density (Norbury et al. 2002). Arguably this information was not required in the past when the consequences of no control rapidly became expressed in unacceptable rabbit numbers. However, since the introduction of a biocontrol agent, rabbit haemorrhagic disease (RHD), to New Zealand – have declined (Parkes and Norbury 2004). Control by habitat manipulation such as warren ripping is a common post-RHD control strategy in Australia where its benefits are additive to those from RHD, but the method has little relevance in New Zealand, where rabbits rarely live in warrens. The question remains whether the costs of such traditional control in the presence of the effects of RHD are warranted by the marginal benefits to production that might accrue. We need to understand the relationships between rabbit densities, sheep numbers and pasture production to make a rational judgement.
We undertook a replicated experiment that measured the impacts of sheep and rabbits at a range of densities on pasture biomass in semi-improved pasture in the rabbit prone region of Central Otago, New Zealand.
|Author||Reddiex, B., Parkes, J., Heyward, R. and Scroggie, M.|
|Secondary title||13th Australasian Vertebrate Pest Conference|
|Place published||Wellington, NZ|
|Control method||Biological Control|