Since being introduced in Queensland in 1935, cane toads have spread around vast areas of northern Australia. Attempts to contain, suppress or eradicate them on a broad scale have so far been unsuccessful.
Cane toads are generally resilient to adverse environmental conditions – provided the weather is warm and they have access to a suitable water source. Female cane toads can lay between 10,000 and 30,000 eggs in a single clutch and breed on average twice per year.
Cane toads carry toxins that are often fatal when consumed by native animals, such as goannas, lizards, snakes and quolls. They may also compete with native animals for food and habitation. In areas populated by cane toads, there can be serious impacts on biodiversity and the ecology.
Some species may benefit or manage to co-exist with cane toads; for example, certain tropical snakes become more common (as there are fewer goannas around to eat the snakes) and some birds, rodents and insects can eat cane toads without being poisoned.
Economic impacts appear to be uncalculated at this stage. The Committee heard that the cattle industry, lettuce farmers, tourism operators and apiarists could be negatively impacted. Indigenous people have lost traditional food sources, particularly goannas.
Cane toads at the invasion front are now believed to be capable of moving up to 55 kilometres per year – a much greater distance than previously estimated.
Responses to the cane toad problem
The Federal Government currently regards cane toads as a key threatening process. The Environment Protection and Biodiversity Conservation Act 1999 (Cth) states that a process is threatening if it ‘threatens, or may threaten, the survival, abundance or evolutionary development of a native species or ecological community’. A threat abatement plan may be established in response to a threatening process, which ‘must be reviewed by the Minister at intervals of not longer than five years’.
A 2011 threat abatement plan for cane toads states that ‘it is not currently possible to contain or eradicate cane toads’ and that a new approach ‘requires national coordination’. The Department of the Environment and Energy advised that the plan is currently being reviewed.
Cane toad threat abatement plan objectives
The plan has three objectives:
1. Identify priority native species and ecological communities at risk from the impact of cane toads.
2. Reduce the impacts of cane toads on populations of priority native species and ecological communities.
3. Communicate information about cane toads, their impacts and this TAP [threat abatement plan].
Ms Kylie Jonasson (Department of the Environment and Energy) said the Australian Government had provided over $12 million to fund projects related to controlling cane toads. She said funding has recently been provided under the National Environmental Science Program.
The Federal Government also has treaty obligations to protect and conserve biodiversity, a responsibility shared with the States and Territories and each jurisdiction has their own regulations for controlling invasive species. Landholders, Indigenous groups, community groups, non-government organisations and businesses also contribute to biodiversity conservation. The cooperation of governments, organisations and individuals is relied upon to progress implementation of threat abatement plans.
In addition to cane toads, key threatening processes also include rabbits, foxes, feral cats, feral pigs and escaped garden plants.
The Department of the Environment and Energy submitted:
The Australian Government provides national coordination through overarching strategies and through species specific or site-specific plans. These strategies and plans allow state, territory and local government, local groups, non-government organisations and landholders to understand how their contribution fits into a broader picture and to provide best practice guidance on how to undertake appropriate management actions.
The Department advised that cane toads are subject to the Australian Pest Animal Strategy 2017-2029.
Australian Pest Animal Strategy – principles for effective pest animal management
1. Prevention and early intervention to avoid the establishment of new pest animal species is generally more cost-effective than ongoing management of established populations.
2. Pest animal management is a shared responsibility between landholders, community, industry and government.
3. Management of mobile pest animals requires a coordinated approach across a range of scales and land tenures.
4. Management of established pest animals should focus on the protection of priority assets (for example, a lambing paddock or a threatened ecological community) but also usually requires a ‘buffer’ management area around the asset to account for pest animal mobility.
5. Pest animal management should be based on actual rather than perceived impacts and should be supported by monitoring to measure whether impact reduction targets are being achieved.
6. Best practice pest animal management balances efficacy, target specificity, safety, humaneness, community perceptions, efficiency, logistics and emergency needs.
7. Best practice pest animal management integrates a range of control techniques (including commercial use where appropriate), considers interactions between species (such as rabbits and foxes) and accounts for seasonal conditions (for example, to take advantage of pest animal congregations during drought) and animal welfare.
8. The cost of pest animal management should be borne by those who create the risk and those who benefit from its management. Governments may co-invest where there is a net public benefit from any such intervention.
The Chief Environmental Biosecurity Officer (based in the Department of Agriculture and Water Resources) provides policy assistance and other support in relation to the environmental impact of foreign pests and diseases.
The Western Australian Government has adopted a strategy for mitigating the spread of cane toads, separate to the Federal Government’s threat abatement plan.
Key elements from the Western Australian Government’s cane toad strategy are provided below.
Western Australia cane toad strategy goals and principles
The strategy’s goals are to:
1. Maximise understanding of cane toads, their impacts and management options.
2. Minimise the impact of cane toads.
3. Implement long-term cane toad management.
From 2014 to 2019, the implementation of this strategy is guided by the following principles:
a. Research, monitoring and evaluation of cane toad and native fauna distributions, and innovative management approaches are necessary to facilitate improvements in management over time within an active adaptive framework.
b. Taking effective action by using scientific information and best practice techniques to protect native wildlife and environments from cane toads.
c. Collaborative partnerships are vital, particularly with Traditional owners, to ensure a continued shared commitment to effective cane toad management.
d. Integration of cane toad management with other land management activities such as the Kimberley Science and Conservation Strategy and the Commonwealth’s Cane Toad Threat Abatement Plan (2011).
e. Public awareness and knowledge of cane toads and their impacts must be continually improved to assist efforts to manage the impact of toads on the natural environment.
Cane toads are recognised as a key threatening process in New South Wales. The Northern Territory Department of Environment and Natural Resources submitted that cane toads are unable to be managed once established. The Northern Territory Government is now focusing on keeping offshore islands and areas with high conservation values free from cane toads. The Queensland Department of Agriculture and Fisheries has assessed cane toads to be an ‘extreme’ threat species and its website advises that ‘control of cane toads is not enforced as there is currently no available effective broad scale control’. However, as noted in a submission from the Torres Strait Regional Authority, mitigation measures are being taken to prevent cane toads establishing on islands in far north Queensland.
Scientists and volunteer groups have also invested their own efforts in controlling cane toads and research on solutions.
Professor Rick Shine observed that while the impact of cane toads is ‘devastating’, this is ‘limited to a small group of species (apex predators) and to a relatively short timescale’. He submitted:
…control of toads over large areas where they already occur would have little benefit for biodiversity, and likely is impossible without resorting to methods (e.g., genetic manipulation) whose risks outweigh the benefits.
Professor Shine suggested that controlling cane toads is more likely to be effective for isolated populations, on islands or near the edge of their distribution. He added that ‘killing adult cane toads will have no impact if reproduction can continue’. Professor Shine’s submission included a previously published article with further background and analysis of the methods used to control cane toads. Professor Mike Letnic made similar observations in his submission:
Despite enormous efforts expended on cane toad control, at best they have only achieved minimal population reduction at small-scales and appear entirely ineffective to limit ongoing invasion across Australia.
A submission from the Northern Territory Department of Environment and Natural Resources described the challenges of controlling cane toads:
Their high mobility during the rainy season and exceptionally high reproductive output means that they can disperse to and establish in new areas very quickly, often before detection.
Control methods and further ways to control cane toads are discussed in more detail in the next chapter.
Conduct of the inquiry
The inquiry commenced on 28 November 2018. The Committee initiated the inquiry based on its power to examine the annual reports of government agencies, as determined in a schedule issued by the Speaker. The terms of reference can be found in the front pages of the report.
The Committee received 24 submissions and held two public hearings. Witnesses from various locations around Australia gave evidence, either over the phone or in person at roundtable-style public hearings. Details of submissions received and public hearings held can be found in the appendices.
This report relies upon draft transcripts of the public hearings (known as ‘proof Committee Hansard’). Errors or omissions are possible and readers are encouraged to check finalised transcripts when they become available on the Committee’s website for verification.
The Committee wishes to thank all the individuals and organisations who contributed to the inquiry.