Technology advances for vertebrate pest eradication

Abstract

In New Zealand and worldwide feral pigs are a serious threat to biodiversity and agriculture as well as being a known vector for disease. Control options are generally limited to hunting, trapping, fencing and the use of toxins in some countries. The use of the toxins 1080, warfarin and phosphorus to control feral pigs have come under fire due to concerns over welfare and residues and the need to develop more humane and safer toxins has been identified. Pilot trials, carried out by the Invasive Animals Cooperative Research Centre, on pigs in 2006 showed that sodium nitrite (SN) delivered by gavage and freely consumed in bait caused death through methaemoglobinanemia. SN appeared to be humane, with deaths following bait consumption occurring within two hours, with unremarkable poisoning signs. SN whilst effective is unpalatable due to its salty taste and encapsulation or taste masking is necessary to overcome this and ensure adequate bait is consumed. A method of encapsulation developed by researchers at Connovation Ltd in New Zealand enabled succesful free feeding cage and field trials on pigs to be completed. A bait containing this encapsulated SN was registered in New Zealand in 2013 for the control of feral pigs and brushtail possums. The results from these initial trials and learnings post registration are to be presented in this talk. Registration trials with this formulation of encapsulated SN are now underway in the USA and Australia.