Advancing a humane alternative to sodium fluoroacetate (1080) for wildlife management - welfare and wallaby control

Context. Control of mammals is a controversial area and ecological and ethical justification is needed, with consideration of animal welfare being increasingly important. Australia and New Zealand are facing resistance to the continued use of sodium fluoroacetate (1080) because of its questionable humaneness, relative to cyanide, as well as other non-intended impacts. Wallabies are sometimes deemed unwanted pests requiring control in both Tasmania and New Zealand. We consider there is an ethical obligation to find humane tools and alternatives to 1080 for wallaby control.

Aims. Two studies on captive animals were undertaken to assess the effectiveness and humaneness of Feratox cyanide pellets for culling Dama wallabies (Macropus eugenii) and Bennett's wallabies (Macropus rufogriseus).

Methods. Cyanide pellets were presented in palatable non-toxic bait to 20 Dama and 24 Bennett's wallabies individually housed in spacious pens. Following ingestion of the toxic pellets by the wallabies, the effects of cyanide on these animals were closely observed.

Key results. In all, 18 of 20 Dama wallabies presented with a pellet died. The mean time from cracking a cyanide pellet to unconsciousness was 7.7min, and 13.5min to death. In the separate trial of 24 Bennett's wallabies, 23 of those cracked at least one Feratox pellet in their mouth and died. The mean time from cracking a pellet to unconsciousness was 14min, and the time to death was 22min. In both studies, cyanide induced toxicosis and death occurred rapidly. The onset of symptoms and effects were similar to those previously reported in possums following ingestion of cyanide.

Conclusions. Feratox has a short interval from onset of symptoms to unconsciousness in wallabies, with few undesirable signs from the welfare perspective.

Implications. Public support is one of several factors influencing the choice of toxins. Toxin use for pest control will be sustained only if the control tools used are humane. On that basis, cyanide offers a preferred alternative to other vertebrate toxins, including 1080, for the control of wallabies.