Pest control using aerially-distributed 1080 bait could threaten non-target native bird species either by primary or secondary poisoning. To understand the impact of aerial 1080 control on the abundance of mohua (Mohoua ochrocephala), a vulnerable endemic forest bird, we analysed bird counts from the Catlins State Forest Park recorded over the period 1998-2002. Statistical modelling showed that mohua occupancy varied during the study and actually increased after 1080 control in 1999,
but not significantly so. Concurrently with high predator numbers in the area during a beech (Nothofagus spp.) mast event, mohua abundance significantly declined in 2001 but then recovered in 2002. In conclusion, this study shows no negative effect for the nationally vulnerable mohua following a single aerial 1080 possum (Trichosurus vulpecula) control operation. In fact, with improvements in the experimental design
and survey effort this study suggests future work could show positive effects of aerial possum control on populations, based on the increase in mohua occupancy observed directly after 1080 application
