Tissue residue levels in rabbits and rats poisoned with 1080 One-shot bait and the location of poisoned rabbit carcasses

Abstract

The level of fluoroacetate (1080) found in the carcasses of rats and rabbits poisoned with 1080 ranged from 1.9 to 14.4 μg g^–1 (mean 5.3 μg g^–1, n = 11) in rats and <0.02 to 0.78 μg g^–1 (mean 0.353 μg g^–1, n = 10) in rabbits. The concentration of fluoroacetate in the blood and liver of both species was generally higher than in the carcasses, and ranged from <0.02 to 33.6 μg g^–1. Fifteen of 22 collared rabbits, and 3 freshly killed, uncollared rabbits were recovered during a routine baiting exercise with 1080 One-shot oats. Excluding the 4 collared rabbits taken by predators, only 14% of all carcasses (n = 14) were found in the open, with the remaining 86% of carcasses being well concealed in warrens or under thick scrub. The carcasses of both rabbits and rats showed considerable decay within 6 days of poisoning. Except for eutherian carnivores, which are highly sensitive to 1080, there is little potential risk of secondary poisoning of native wildlife as a result of the correct use of 1080 baits in pest-control programs.