2ND-GENERATION RODENTICIDES AND POLECATS (MUSTELA-PUTORIUS) IN BRITAIN

In Britain, polecats Mustela putorius hunt around farm buildings, espe cially in winter, and, as a result, may be secondarily exposed to rode nticides by eating contaminated prey. This paper reports the first sur vey of second-generation rodenticides in polecats. Twenty-nine adult p olecats which had been killed either accidentally on roads (24) and in traps (4), or had died of an unknown cause (1) were collected during 1992-1994. The livers of 24 animals and the stomach walls of the remai ning five, for which the livers were not available, were analysed for difenacoum, bromadiolone, brodifacoum and flocoumafen. In total, roden ticide residues were detected in 31% of the polecats analysed. Residue s were found in seven of the 24 livers (29%) and in two of the Jive st omachs analysed (40%). Difenacoum was detected most frequently (28% of animals), and was the only rodenticide in the stomach, while bromadio lone and brodifacoum were detected in only 10% and 3% of polecats, res pectively. Flocoumafen was not detected in any animals. More than one rodenticide occurred in the livers of two animals; one contained difen acoum and bromadiolone, the other also contained brodifacoum. There wa s no sex bias in the proportion of animals containing rodenticides. An imals with detectable residues came from more than one county and were collected only during January-April in each year.