Ranking the Negative Impacts of Wildlife Control Methods May Help to Advance the Three Rs

the welfare of individual animals can be compromised during wildlife research and when scientific practices are applied in the field. One important aspect of wildlife science and management is the control of pest organisms; such control is undertaken for various reasons including to reduce economic losses, to minimize disease transmission, and for conservation purposes (Littin and Mellor, 2005). In New Zealand, pest control is particularly important because of the unique endemic fauna present and the ongoing dramatic reduction in native populations due to competition and predation from introduced mammalian species (Littin et al., 2004). In New Zealand, mammalian pest animals are commonly controlled using various lethal vertebrate toxic agents (VTAs). It is acknowledged that these methods have the potential to compromise the welfare of pest animals (Littin et al., 2004; Littin, 2010). However, although the welfare impacts of some individual VTAs have been assessed (e.g., Eason et al., 1998; Gregory et al., 1998; Littin et al., 2000, 2002), and research aimed at improving the humaneness of several VtAs is ongoing (littin et al., 2004; Marks et al., 2009), there are few, if any, published comparisons of their relative effects. Systematic evaluation of negative welfare impacts is the first step to successful application of 3Rs strategies. It is necessary first to identify potential and actual negative welfare impacts associated with scientific procedures to guide the development of targeted mitigation strategies and to evaluate the success of such strategies for reducing welfare compromise in research animals (Mellor, 2012). Successful mitigation strategies may then be implemented during field use of the control methods. In addition, ranking the relative impacts of various pest control methods will allow selection of the “most humane” method for use in the field, i.e., the one with the lowest negative impacts on welfare. The purpose of this paper is to briefly outline general principles derived from a systematic evaluation of negative welfare impacts associated with VTAs used in New Zealand as they relate to the development, application, and evaluation of the 3Rs in wildlife science.