Bat poisoning prosecution highlights continued use of organochlorines

All Britain's 15 native bat species, whose numbers have declined rapidly in recent years, are protected under the Wildlife and Countryside Act 1981. Anyone intending to disturb a bat colony resident anywhere but in the living-area of a house must notify the Nature Conservancy Council (NCC) and allow it to advise on whether the operation should be carried out and, if so, how.

On 18 January, Skipton Magistrates' Court heard that Protim Services Ltd had treated roof timbers in a house in Grassington, Yorkshire, without consulting the NCC. The roof had housed a colony of at least 200 whiskered bats, but these will probably die on exposure to the pesticide, which contains 2% Pentachlorophenol and 0.5% lindane. Protim were fined £1,000 with £350 costs.

The broader issue raised by the case is why approval for these pesticides has not been withdrawn by the Advisory Committee on Pesticides when alternatives based on the synthetic pyrethroids are now available. At least on manufacturer, Wellcome, and a dozen formulators such as Cuprinol and Sovereign, now supply products based on permethrin or cypermethrin.

Research carried out at Aberdeen University's Department of Zoology has established that both products have no acute effects on bats. They are, however, currently a little more costly, and timber treatment firms are not giving the full 30-year guarantee available with organochlorine-based preservatives until the pyrethroids' long term efficacy has been established.