International consultancies and reviews
Reviewing control options for rats in South East Asia
Over the last few years, Wendy Ruscoe has been contracted by the Australian Centre for International Agricultural Research (ACIAR) to undertake end-of project reviews for ‘rats-in-rice’ projects funded by ACIAR for:
- A systems approach to rodent management in upland environments in Lao
- Farmer-based adaptive rodent management, extension and research in Cambodia
- Implementation of rodent management in intensive irrigated rice production systems in Indonesia and Vietnam.
The aim of all these projects has been to reduce the damage done to rice and rice stores by native pest rodents. Wendy reviewed both the science and management recommendations in collaboration with the project scientists. The projects included ecological understanding of rodent biology, reproduction and movement in cropping systems and how this knowledge has been used to better manage pest rodents with traditional (non-poison) methods which conserve non-pest species. The control practices developed by the scientists involve whole-community actions timed to the biology of the rats and the cropping cycle. Wendy travelled to the rice-growing communities to ask them (1) how methods of rodent control had changed over the duration of the project, (2) if the amount of rice they were able to grow and store had changed, and (3) how increased production had changed their lives. Farmers spoke of increased food for their families, less money being spent on poisons, and increased community awareness as community members had to work together in their fight against rats.
Analysing samples for vertebrate pesticides
Landcare Research’s toxicology laboratory specialises in analysing environmental samples for traces of vertebrate pesticides, in particular 1080, cyanide and brodifacoum. Its clients typically include local authorities, pest control companies, other laboratories, government departments and universities, but it also analyses samples for international clients.
Biological samples coming into New Zealand are subject to permits from MAF, and the laboratory is experienced in facilitating these arrangements with clients with appropriately accredited containment. Samples to date have been highly varied and have included innocuous plant material, meat baits, rat and dog urine, mouse whiskers, blood and liver tissues, whole crabs and horse stomach contents. In particular, overseas clients recognise the laboratory’s long history and experience in analyses for 1080 and anticoagulant rodenticides in vertebrate tissues, water and soil samples.
Alternatives for the control of mammalian pests in Tasmania
In 2006, a team led by Bruce Warburton reviewed the research needs of a programme established to determine alternatives to 1080 for the management of browsing damage by mammals in Tasmania. The team identified a number of key research projects and these formed the basis of a 4-year, $4 million research programme funded by the Tasmanian State Department of Primary Industries and Water.
Between March 2010 and August 2011, Dave Morgan was contracted to conduct an independent review of the research undertaken. He reported that the programme had invested in a wide range of relevant research and extension to meet its strategic objectives, and had delivered good-to-excellent value for money on all investments despite the infl uence of a number of powerful constraints (e.g. the short-term and broad focus of the programme, the complexity and variability of affected ecosystems, and public disapproval of lethal control). The most significant achievements of the programme were:
- A better understanding of the utility of existing control options (fencing, shooting, and trapping) based on refinements in techniques, assessment of costs, and production of ‘best practice’ information
- The trialing of Feratox, a cyanide-based pesticide for controlling wallabies
- Quantification of the relationship between native browsing mammals and damage on farmland
- Growing recognition of the need to manage browsing mammals at a landscape scale.
Rat versus rat to prevent re-invasion
At present, invasive black (ship) rats occupy patches of remnant native bushland around Sydney Harbour. They are hosts for the lungworm Angiostrongylus cantonensis, which can also infect humans, and they prey on a variety of Australian native species in the same way they cause major ecological problems in New Zealand. Although local control of rats is technically feasible, the benefits of control are lost rapidly due to reinvasion from surrounding suburbs. Professor Peter Banks and his team from the University of Sydney, with input from Andrea Byrom and Roger Pech of Landcare Research, are experimenting with a novel solution to this problem. The idea stems from PhD research conducted several years ago by Vicki Stokes (supervised by Peter Banks, Roger Pech and Dave Spratt) who showed that competition between black rats and native bush rats is very evenly balanced. The species that gains a temporary advantage in occupying an area is able to hold its ground indefinitely. So, in July–August this year, black rats were removed from four sites around Sydney Harbour. In mid-August, bush rats from a nearby national park were translocated to the removal sites and over the next year their ability to repel invading black rats will be monitored using a combination of techniques including chewcards, cameras, and live-trapping. If successful, the experiment will demonstrate how using, or perhaps enhancing, the competitive ability of native species can result in long-term, sustainable exclusion of invasives from urban areas without the need for poisons or traps.