Compound 1080 (sodium monofluoroacetate) has been used in Tasmania for control of introduced rabbits since the early 1950s and for the native Bennett’s wallaby, Tasmanian pademelon, and brushtail possum for almost as long. Recently, public pressure has resulted in a target to phase out the use of 1080 by 2015. In 2005, the Australian and Tasmanian Governments announced funding for a program to assist in the development of alternatives to 1080. Following an initial independent review in 2006, research and demonstrations focussed on fencing and barriers; shooting, trapping and behavioural research; alternative toxins and delivery mechanisms; repellents; and damage / control relationships. The most positive outcomes from the program were increased understanding of the complexity of the Tasmanian browsing damage problem and the need to measure and address the damage, rather than count the numbers of animals culled. For those agricultural producers who had used it, wallaby-proof fencing was thought to be the most effective long-term control option, despite the increased costs of materials and maintenance. Fencing is not suitable for all situations, including most forest production areas; it is not a stand-alone control option, as it must be accompanied by culling at construction and over time. Shooting is the second-most-important method of control, and there is scope for improvements in effectiveness through better practices and equipment. Trapping can be useful in some areas but it is expensive, and current traps will not catch Bennett’s wallabies. Repellents have not proven to be effective, and further developmental work is required before Feratox® can be recommended for safe use in Tasmania.

Compound 1080 has been used to control native wallabies and possums in Tasmania for over 50 years. Public concern in relation to humaneness and its effects on domestic dogs and nontarget species has led to opposition to its use. Feratox®, a form of encapsulated cyanide pellet registered for brushtail possum control in New Zealand, was considered as a replacement toxin. Trials in New Zealand showed that the material is fast-acting and humane in wallabies. In Tasmania, protocols were developed using bait stations that would minimise access by nontarget macropods and wombats. In field trials using Feratox®, however, there was excessive spillage of toxic pellets and variation in bait take between seasons by Tasmanian pademelons. Further work is under way to resolve these issues to see if protocols can be developed for the safe and effective use of cyanide pellets in areas where nontarget mammals are prevalent.

In New Zealand, sodium fluoroacetate (1080) has been used for vertebrate pest control for several decades. Since the 1990s, some 1080 users have switched to brodifacoum for possum and rodent control because of its ready availability and ease of use. An awareness that field use of brodifacoum results in persistent residues provides the impetus to develop alternatives and provide new tools and greater flexibility. Looking to the future, we seek toxins which increasingly combine “low-residue” characteristics with humaneness, and more selective bait and delivery systems enabling better and more acceptable control of possums, wallabies, mustelids, rodents, feral cats, and rabbits. Experience gained in the 1990s with the introduction of cholecalciferol (Feracol®) and a cyanide pellet (Feratox®), which both kill possums without secondary poisoning, underpins the extension in 2009 of the Feratox® registration to include introduced Dama wallabies. To date, zinc phosphide has not been registered in NZ, despite its field use in Australia and the U.S. and low secondary poisoning risk compared with 1080. Research and registration dossiers are being assessed in 2009-10 for zinc phosphide containing products for possum and rodent control. Registration documents are also being prepared for a combination of cholecalciferol and coumatetralyl to provide a slow-acting alternative to brodifacoum for the field control of possums, rodents, and rabbits with low risk of bio-accumulation. Anticipated timelines for product availability are 2010 (zinc phosphide) and 2011-13 (cholecalciferol and coumatetralyl). Our intention now is to move beyond these conventional rodenticides and develop new vertebrate pesticides. For example, we are pursuing the registration of para-aminopropiophenone (PAPP) for humane control of stoats and feral cats, and a series of related novel toxins and other compounds that target the red blood cell for other pest species including rodents. PAPP products should be available in 2010, subject to registration approvals. New research initiatives in 2010 will increasingly result in a shift in focus to the development of novel rodenticides aided by new international research collaborations.