Anticoagulant rodenticides in stoats (Mustela erminea) and weasels (Mustela nivalis) in England

Concentrations of six anticoagulant rodenticides were examined in the liver s of stoats Mustela erminea L. and weasels Mustela nivalis L. trapped or sh ot by gamekeepers between August 1996 and March 1997. Residues of rodentici des were detected in nine out of 40 stoats (23%) and three out of ten wease ls (30%) from live out of eight estates in central and eastern England. Bro madiolone (0.04-0.38 mg kg(-1) wet wt) was detected in three stoats and one weasel, coumatetralyl (0.0085-0.06 mg kg(-1)) in six stoats and three weas els and brodifacoum (0.12 mg kg(-1)) in one stoat. One stoat and one weasel contained combinations of two rodenticides. Exposure to rodenticides was m ore prevalent in female stoats than in males. Rodenticides were widely used away from buildings on the sampled estates and so mustelids need not forag e around buildings to be exposed. We conclude that stoats and weasels are s econdarily exposed to rodenticides mainly by eating non-target species. (C) 1998 Elsevier Science Ltd. All rights reserved.