Lack of scientific evidence and precautionary principle in massive release of rodenticides threatens biodiversity: old lessons need new reflections

Abstract

Pesticides are widely used throughout the world to control agricultural pests (Berny 2007). Owing to their well identified side-effects on wildlife (see for example Newton et al. 2000; Brakes & Smith 2005), the release of high quantities of pesticides to the environment should always require responsible use of both science-based information and the precautionary principle (Mason & Littin 2003). However, decision making in wildlife management and conservation is not systematically supported by scientific evidence (Pullin & Knight 2005). This is particularly worrying when decision making involves release of toxic substances to the environment, as often occurs in rodent plague control. Here we describe how poorly-informed management decisions to control a rodent plague can adversely affect wildlife, especially when chemical-based treatments are generically designed and applied on a broad scale, and discuss the high economic cost of such campaigns. We urge the implementation of a more cost-effective evidence-based and environmentally sustainable management to control rodent plagues in Spain. Cases similar to those reported here occurred in the UK a century ago, and throughout Europe in the 1950s (Elton 1942; Chitty 1996). Although abundant scientific information has since been generated about vole cyclic population dynamics and rodent plague control techniques in the world, lessons have apparently not been learned.