How a wallaby and 1080 poison don't mix!

Tasmania is the only State in Australia which still allows native animals to be poisoned. 1080 is widely used throughout the State. After years of public condemnation, the Tasmanian Government has stopped the use of 1080 in public forests. However the private sector has tripled the use of 1080 in the last 12 months. (2006)

The tourist image of Australia as a "clean, green, pristine, natural State" is adversely affected by the use of 1080 to poison native wildlife. In May 2005 a massive 1080 baiting operation took place on King Island. Landholders said it would kill "tens of thousands" of wallabies. Protests across Australia and around the world were the result.

The Tasmanian Wildlife Tourism Strategy 2005 states that 86 per cent of tourists want to see Tasmanian wildlife in its natural habitat.

The policies that have driven a lack of vision in vertebrate pest control have not served Australian agriculture and the environment well. The currently narrow vision of vertebrate pest control technologies and possibilities should not be maintained. It is no exaggeration that there is great potential for some of the current practices to cause boycotts and economic hardship to Australian agriculture.

The public subsidy of 1080 poison and the ready issue of crop protection and recreational shooting permits encourages landholders to use lethal means rather than non-lethal means to control wallaby numbers. In fact the logical response of most people who have their products eaten by animals would be to protect their crop.

As concerns for animal welfare are likely to increase in the foreseeable future, this will require a forward looking strategy that encourages innovative approaches and provides farmers with the tools to control browsing native animals that threaten their viability - specifically, humanely and cost-effectively.

Since 1080 is essentially stable it will remain toxic in carrot bait as long as the bait resists weathering, but is readily leached from carrot by rain. Griffiths (1959), working in New South Wales, found that carrot baits retained their initial potency over 9 days of sunny dry weather even though the carrot had been sun-dried to a hard black detritus.

In low rainfall areas or under arid conditions, uneaten baits will always be a problem for domestic stock. If the baits become dehydrated they will persist for many weeks without losing toxicity. Then, heavy dew or rain may render them palatable to native animals or stock (Staples 1969). Sensitivity ranking of the different animal groups On the basis of all LD50 data available, McIlroy (1986) was able to rank the different groups tested according to their sensitivity to 1080 (Table 5). Marsupial carnivores (e.g. Tasmanian devils, Tiger quoll and Eastern quoll) tend to be the first animal group to show signs of 1080 poisoning and the first to die.

A summary of the research shows that Mammals are more sensitive to 1080 than birds. Birds are more sensitive than reptiles and amphibians. Eutherian carnivores, eutherian herbivores and marsupial herbivores from Eastern Australia are most sensitive (99% level). Herbivorous animals tend to be more sensitive to 1080 than carnivores, insectivores and omnivores.

Is 1080 A Risk to Human Health? As there is no reliable chromatography or bio-assay to detect the presence of 1080 in wallaby flesh, there is a real risk of human poisoning. There is no Australian testing facility. Symptoms of lethal dose would appear as a seizure and heart attack and sub-lethal effects would be hard to diagnose.

There is currently no clinically effective antidote to 1080. Yet the government permits wallaby meat to be sold for human consumption. If there is a single incidence of a consumer becoming ill after having consumed wallaby meat that was sourced from an area where 1080 poison baits were laid the publicity impact would prove very costly for primary producers everywhere, and for the tourist industry.

Tourism Tasmania research showed that 86 per cent of tourists want to see Tasmanian wildlife in its natural habitat, not in a zoo and not on a plate. Surveys of Tas. restaurants serving wallaby meat show that tourists have expressed adverse opinions, and even walked out, because they object to this practice.

Vertebrate pest control will be more successful if a variety of methods are used in conjunction with one another. Alternative control options include fencing, tree guards in plantations, repellents and reproductive control methods.

REPRODUCTIVE CONTROL - Macropods and embryonic diapause Much research has been done on a variety of methods of reproductive control but, so far, none have proved to be cost-effective. However, wallabies and other macropods have a remarkable reproductive cycle by which they regulate births according to the rainfall and vegetation growth. This unique birth control system, called "embryonic diapause", enabled them to live, in balance with their habitat, since the last Ice Age even on offshore islands. If fenced out of farmland, wallabies will regulate their reproductive rates to accord with the available vegetation growth. When macropods cannot access pastures they their reproductive rate will not increase.

EXCLUSION FENCING Trials with 'wallaby wire' have proved to be very effective in keeping wallabies from pasture (Statham and Rayner 1995) Tasmanian Insitute of Agricultural Research (TIAR) research - 2000-2001 (Dr M. Statham, P. Rayner, Greg Finnigan, H. Statham.)

Trials in four areas of Tasmania defined the losses of farm animal productivity due to competing browsing native animals. This research examined whether wallaby proof fencing reduced economic losses from browsing wallabies. At each site there was a 5ha plot with wallaby proof fencing and a second with normal fencing. Measurements were made of the number of grazing days from each plot. The three trials showed that properly installed wallaby proof fencing was effective and in the absence of wallabies over 35% more stock could be carried.

The loss of productivity on unfenced pastures was again confirmed in a recent University of Tasmania study (K. Bridle).) It concluded that wildlife were taking 40pc of available grazing on the 2100 hectare property owned by sheep farmers Tom and Cynthia Dunbabin.

Some farmers claim that to erect fences, particularly across undulating land, is not cost effective.

The Australian Government Department of the Environment and Heritage (DEH) has produced a detailed catalogue of cost effective animal exclusion fencing. This catalogue compiles schematic diagrams and specifications of fences that have been used to exclude the specified feral animals (foxes, feral cats, feral rabbits, feral goats, feral pigs and dingoes/feral dogs). Netting fences shown in this catalogue to exclude rabbits are much the same as those used in the TIAR trials to exclude wallabies and pademelons. The estimated cost of materials is $3,700/km It is suspected that fences in some areas fences may restrict movements of non-target species in their natural home ranges. For instance wombats and bettongs may be unable to move between their resting and feeding areas where these fences are placed along a paddock/forest edge.

The Government should investigate methods by which farmers could access government guaranteed low/no interest loans to assist with the cost of fencing. Their 35-40 per cent increase in productivity should enable farmers to repay these loans. The public subsidy of 1080 poison and the ready issue of crop protection and recreational shooting permits encourages landholders to use lethal means rather than non-lethal means to control wallaby numbers.

Sound and Odour Repellents should also be intergrated into crop protection measures such as fencing.

Back to Kangaroo and Wallaby home page!