Susceptibility of four bird species to para-aminopropiophenone (PAPP)

Abstract

The suitability of para-aminopropiophenone (PAPP) for the humane control of stoats (Mustela erminea) and feral cats (Felis catus) is being investigated in New Zealand. Birds are potential non-targets that may be affected by this toxin. Therefore, the objective of this study was to test the toxicity of a proprietary formulation of PAPP in four bird species: Australian magpies (Gymnorhina tibicen; n = 40), blackbirds (Turdus merula; n = 20), mallard ducks (Anas platyrhynchos Pekin breed; n = 20) and weka (Gallirallus australis; n = 21). Birds were orally dosed with PAPP in the form of a 40% paste that had been added to meat as a delivery vehicle. The lethal dose to kill 50% of the sample (LD₅₀) was 1387 mg/kg for magpies, 174 mg/kg for blackbirds, 32 mg/kg for mallard ducks and 568 mg/kg for weka. However, the LD₅₀ value for weka underestimates the risk to this species, as individuals were affected at the lowest dose tested (62 mg/kg), becoming subdued and losing their appetite until they were euthanized 30 h after dosing. Whilst birds are less susceptible to PAPP than stoats or feral cats (LD₅₀ for both of these species is < 10 mg/kg), some bird species are adversely affected, so it will be important to limit their exposure.