Aerially distributed baits containing sodium fluoroacetate (1080) are used in New Zealand for small-mammal pest control over an average of about 600 000 ha each year. This can also kill non-target species, including deer. This incidental mortality of deer generates antipathy to 1080 amongst many hunters, adding to the broader opposition to aerial 1080. Hunter opposition to 1080 baiting has also prompted the development of deer-repellent 1080 bait formulations. Historical estimates of deer mortality varied widely but were sometimes high.
Sowing 1080 baits for vertebrate pest control in clusters, rather than evenly, could potentially reduce toxin use. We developed a new technique for aerial delivery of 1080 baits in clusters and, in a set of four trials, compared its efficacy in controlling pests against conventional aerial broadcast baiting. In an initial trial where non-toxic prefeeding was not used (Molesworth Station, North Canterbury) we confirmed that aerial delivery of bait clusters is technically feasible and operationally practical.