USDA National Wildlife Research Center Symposia


Date of this Version

August 2007


Published in: Witmer, G. W., W. C. Pitt, and K. A. Fagerstone, editors. 2007. Managing vertebrate invasive species: proceedings of an international symposium. USDA/APHIS Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado, USA. Also available online at


The endemic fauna of New Zealand evolved in the absence of mammalian predators and their introduction has been responsible for many extinctions and declines. Predator control will have to be on-going if some native species are to survive on the mainland. Currently, predator control relies largely on labourintensive trapping, so the development of humane predator-specific toxins would provide valuable additional control methods. Para-aminopropiophenone (PAPP) is being investigated as a toxin for feral cats (Felis catus), stoats (Mustela erminea), and wild dogs (Canis familiaris). Carnivores appear to be much more susceptible to PAPP than birds, so it potentially has a high target specificity, at least in the New Zealand context. Pen trials with 20 feral cats, 15 stoats, and 14 dogs have been undertaken using meat baits containing a proprietary formulation of PAPP. A PAPP dose of 20-34 mg/kg was lethal for feral cats, 37-95 mg/kg was lethal for stoats, and 26-43 mg/kg was lethal for dogs. Our results suggest that PAPP is a humane and effective toxin for control of feral cats and stoats, and possibly for wild dogs. We are now continuing studies towards product registration, which will include the assessment of non-target effects, particularly on birds.