Risk assessment of stoat control methods for New Zealand

Optimal application of a pest control method requires the paraphernalia of the technique (e.g. the trap, toxin, bait), its acceptable and safe application (e.g. humane use, environmental safety, target specificity), and knowledge of how to apply it strategically (e.g. where, when, how often, how intensively). We review current and potential stoat control methods to identify where the main constraints and risks on their optimal use lie, and suggest ways to overcome these where possible. For traps, the main constraints are an incomplete knowledge of their strategic application, and the main risk is that none, at the time of writing, meet draft animal welfare standards For baits and lures, the main constraints are the lack of a bait designed to meet all managers’ needs, either as a lure to traps or as something all stoats will eat when presented by various methods. For toxins, the main constraint is that currently none are registered for stoat control, and the main risks are the usual concerns about non-target species exposure and public acceptability common to all toxins. For classical biological control, the main risk is the lack of public acceptability of some possible agents (e.g. canine distemper), but the technique is more seriously constrained by the lack of any putative agent that would overcome potentially low transmission rates among non-social animals such as stoats. For immunocontraception, the main risk is that no suitable agent for stoats will be found, and the main constraints are the expense and time needed to identify and test agents and to develop a suitable bait or live vector to deliver the agent. Control of the primary prey of stoats such as rodents is as difficult as stoat control itself, but the use of immunocontraception against species such as mice (the target of current Australian research) might reduce stoat densities in beech forest in mast years. The risks of prey-switching by the remaining stoats would need to be considered before this strategy was adopted. ‘Boutique’ control methods such as the use of dogs and fencing are, by their nature, of limited use-but still of importance.

Author J. Parkes and E. C. Murphy
Date null
Year 2004
Secondary title Science for Conservation
Volume 237
Notes Notes
Region NZ
Documents Risk Assessment of stoat control methods for New Zealand