Improving the efficiency of aerial sowing of baits for possum control

Abstract

Four aerial sowing treatments of non‐toxic possum bait were compared in a pine plantation on flat terrain. Baits were dyed with Rhodamine B and treatments were assessed by the proportion of dye‐marked possums captured. Sowing was least accurate where flight paths were not marked, but the resulting bait‐free patches did not prevent possums from finding and eating bait. Where larger gaps were deliberately created in bait dispersion, acceptance of bait by possums was slower and, overall, less than where coverage was assisted by flight line marking. Sowing bait at a rate of 3 kg/ha was as effective as 10 kg/ha. These results have two main implications for routine aerial control. First, because incomplete coverage of a target area will yield poorer kills, navigation aids should be used in systematic sowing and sowing equipment improved. Second, a cost‐saving can be achieved by reducing sowing rate to 3 kg/ha and possibly lower. Trials are required in other habitat types to test the general applicability of this result.

Keywords:

• possum control
• sodium fluoroacetate (1080)
• aerial sowing