The Effect of Rainfall and Blowfly Larvae on the Toxicity of '1080'-Treated Meat Baits Used in Poisoning Campaigns Against Wild Dogs.

Abstract

Meat baits injected with '1080' poison (sodium monofluoroacetate) according to the method recommended by the Department of Agriculture, New South Wales, Australia, for preparing baits for poisoning compaigns against wild dogs (Canis f. familiaris) and dingoes (C. f. dingo), began to lose their toxicity from the moment of preparation onwards, particularly after different rainfall treatments and when inhabited by calliphorid larvae. The main or most likely reasons for the loss of fluoroacetate were consumption by maggots (mainly larvae of Calliphora augur and C. stygia plus some C. hilli and C. tibialis) and their subsequent disappearance from the baits, leaching by rainfall, defluorination of the fluoroacetate by micro-organisms, and leakage from the baits after injection and during their decomposition. During this study the baits remained toxic to dogs, despite different rainfall treatments, for over 32 days during winter when maggots were absent, and for 6-31 days during summer, when they were present. Under the same conditions the baits contained an LD50 for an average-sized tiger quoll (Dasyurus maculatus) for 4-15 days and 2-4 days, respectively.