The longevity of para-aminopropiophenone (PAPP) wild dog baits and the implications for effective and safe baiting campaigns

Abstract

Considerable effort goes into mitigating the impacts caused by invasive animals and prohibiting their establishment or expansion. In Australia, management of wild dogs (Canis lupus dingo and their hybrids) and their devastating impacts is reliant upon poison baiting. The recent release of baits containing the humane toxin para-aminopropiophenone (PAPP) offers potential improvements for control of wild dogs, but little is known about the environmental persistence of PAPP in manufactured baits that could be used to inform best practice guidelines. We investigated the degradation rate of PAPP wild dog baits (DOGABAIT™) under typical field usage and storage conditions in north-eastern Australia and calculated optimal deployment and withholding periods. The PAPP content of buried baits declines faster than surface-laid baits, but both presentations retained lethal doses to wild and domestic dogs for considerable periods (6-16 weeks). Domestic or working dogs should be suitably restrained or excluded from baited areas for extended periods, particularly under dry conditions, to minimise poisoning risk. The period of persistence of PAPP baits may provide opportunities to improve the duration or longer term efficacy of baiting campaigns, but care is needed to protect domestic and working dogs to ensure responsible and safe use.

Evaluating predator control using two non-invasive population metrics: a camera trap activity index and density estimation from scat genotyping

“…Here, concurrent GPS collaring and camera trap spatially explicit mark-resight analysis provided estimates of 0.05-0.14 foxes km −2 (Carter et al 2019). In contrast, however, densities were substantially lower than those observed in Australian urban and temperate agricultural habitats (Coman et al 1991;Thompson and Fleming 1994;Marks and Bloomfield 1999;Berghout 2001;Gentle 2005); this was expected because foxes have larger home ranges and occur at lower densities when productivity is low.…”

“…The likelihood of foxes consuming a toxic dose will decrease with bait avoidance and caching (Allsop et al 2017). Trialling other bait matrices to improve palatability (Van Polanen Petel et al 2001), trialling other poisons with greater efficacy (Southwell et al 2011;Gentle et al 2017) or combining baits with canid pest ejectors (Marks et al 2002) may result in more rapid consumption of baits. Scat genetic analysis is evidently a valuable technique to refine baiting and monitoring regimes and for estimating fox densities.…”

Minimizing animal welfare harms associated with predation management in agro‐ecosystems

“…The traditional approach attempts to maximize economic outcomes by protecting livestock while the contemporary approach attempts to maximize biodiversity outcomes by protecting predators. However, neither approach is focused on maximizing animal welfare outcomes by minimizing harm to all animals (Allen, 2017;Hayward et al, 2019;Johnson et al, 2019).…”

“…The total number of wild dogs killed across Australia by all these methods is unknown. However, coarse estimates derived from local information on wild dog abundance, poison usage, and bounty data suggest that approximately 10,000 to 20,000 wild dogs are killed across Australia each year from a population of approximately 26,000 to 52,000 adult wild dogs that produce a similar number of offspring each year (Allen et al, 2015a(Allen et al, , 2017Harris, 2016). The harms associated with these common wild dog control tools are described below.…”

“…Many animal welfare scientists strongly discourage the use of 1080 for these reasons (Sherley, 2007;Littin et al, 2014). PAPP is used to control a variety of canid, felid and mustelid predators in Australia and New Zealand (Eason et al, 2014;Gentle et al, 2017). The mode of action for PAPP is through conversion of normal haemoglobin in red blood cells to methaemoglobin, thereby inducing cyanosis (Marrs et al, 1991;Wood et al, 1991;Eason et al, 2014).…”