Efficacy of lethal-trap devices to improve the welfare of trapped wild dogs

Abstract

Context Wildlife and pest managers and stakeholders should constantly aim to improve animal-welfare outcomes when foot-hold trapping pest animals. To minimise stress and trauma to trapped animals, traps should be checked at least once every 24h, normally as soon after sunrise as possible. If distance, time, environmental or geographical constraints prevent this, toxins such as strychnine can be fitted to trap jaws to induce euthanasia. However, strychnine is considered to have undesirable animal-welfare outcomes because animals are conscious while clinical signs of intoxication are present. A toxin considered more humane, para-aminopropiophenone (PAPP), is available to induce euthanasia in trapped animals but is untested for presentation and efficacy. Aim We tested the efficacy of two types of lethal trap device (LTD’s), each using a paste formulation of PAPP as the active toxin to replace the use of strychnine on foot-hold jaw traps. Methods Elastomer LTDs and PAPP-cloths were fitted to jaw traps set to capture wild dogs (Canis familiaris). Camera-trap data was used to record animal behaviours after capture and to determine the efficacy of both modalities. Key results Every trapped wild dog (n=117) gnawed at the elastomer LTD’s or PAPP-cloth attached to the trap jaws that restrained them; one dog failed to liberate the toxin. From the dogs caught in the main trial (n=56), a mortality rate of 84% and 87% was reported respectively. The mean time from trap-to-death for elastomer LTDs was 64min and 68min for PAPP-cloths. Conclusions Elastomer LTDs and PAPP cloths combined caused the mortality of 85% of captured dogs. This efficacy could be improved by adopting the recommendations discussed in the present study for deploying PAPP-based LTDs during trap deployment. Implications PAPP-based LTDs offer an alternative option to the use of strychnine and improve the welfare outcomes for trapped predators, especially where traps are not checked within the recommended 24-h period.

Animal welfare considerations for using large carnivores and guardian dogs as vertebrate biocontrol tools against other animals

“…Eldridge et al, 2002;Campbell et al, 2019) and welfare impacts (e.g. Fleming et al, 1998;Marks et al, 2004;Meek et al, 2019;Allen et al, In press), to date there has been very little consideration of the animal welfare implications of deliberately using predation and/or fear of predation as a wildlife management tool (Allen et al, 2017). This is symptomatic of the disproportionate animal welfare scrutiny that is applied to different conservation practices, with human-caused predation representing an under-addressed issue (Hampton and Hyndman, In press).…”

“…This includes, for example, the development and adoption of less-harmful traps and similar devices, less-harmful poisons, and more-effective strategies for their use (e.g. Marks et al, 2004;Anon, 2014;Eason et al, 2014;Meek et al, 2018;Meek et al, 2019;Allen et al, In press). Great progress has also been made in assessing the relative welfare impacts of wildlife management tools and techniques in some regions of the world (e.g.…”

Activity of dingoes (Canis familiaris) and their use of anthropogenic resources in the Strzelecki Desert, South Australia

“…Dingoes were trapped between 2015 and 2019 by using Victor Soft Catch #3 traps fitted with a short chain and a double-spring system; they were double-staked to the ground by using 40 cm pegs previously described in Meek et al (2019a). A variety of lures was used, and traps were placed strategically around pads and tracks in the study site to optimise encounters by dingoes.…”

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

“…being killed, and can be minimized by checking traps regularly (e.g. daily or twice daily) or using either Trap Tranquilizer Devices (TTDs; Marks et al, 2004), Lethal Trap Devices (LTDs; Meek et al, 2019), or trap-alert devices (Woodford & Robley, 2011). Kill-traps (or traps intended to crush or kill captured animals) cause death, although such trap types are not permitted or used against wild dogs in Australia.…”

“…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). PAPP has several animal welfare advantages over 1080, including a shorter duration of suffering and a less-excitatory mode of action Meek et al, 2019).…”