BRODIFACOUM RESIDUE ANALYSIS IN WATER, SOIL, INVERTEBRATES, AND BIRDSAFTER RAT ERADICATION ON LADY ALICE ISLAND

Rats were eradicated from Lady Alice Island (Northland, New Zealand) i n October 1994, using aerially applied cereal-based bait containing br odifacoum. To determine the fate and non-target impact of brodifacoum, streams, soil, invertebrates, and birds were monitored for 7 months a fter the baits were applied. No brodifacoum was detected in any of the stream or soil samples. Brodifacoum was detected in cave weta found o n baits, and in morepork and red-crowned parakeet liver tissue. Signif icant contamination of water and soil is unlikely after a single aeria l application of brodifacoum baits. Invertebrates such as cave weta ma y be at risk of consuming brodifacoum bait, morepork and red-crowned p arakeet may be at risk of secondary poisoning.