Draft threat abatement plan for competition and land degradation by rabbits

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Review of the 2008 TAP

The EPBC Act requires that a threat abatement plan be reviewed by the Minister at intervals of no longer than five years. The 2008 Threat Abatement Plan for the competition and land degradation by rabbits was reviewed by the Department of the Environment in 2013. The review assessed the progress and effectiveness of the threat abatement plan in: reducing the impacts of rabbits on biodiversity, specifically nationally listed threatened species and ecological communities; and preventing further species and communities from becoming threatened, through research, management and other actions. The review can be accessed at: http://www.environment.gov.au/biodiversity/threatened/publications/tap/competition-and-land-degradation-rabbits. In summary, the review found that:

  • the issues and objectives outlined in the 2008 TAP were still valid and are likely to remain so into the future

  • Rabbits have reached their ecological limit within Australia; threat abatement should therefore focus on minimising their impact rather than further spread

  • There have been several successful eradications of rabbits on offshore islands in the last five years, most notably the eradication from Macquarie Island

  • Exclosures have been useful in quantifying the impacts of rabbits on native flora and fauna

  • Rabbits inhibit the regeneration of plants at densities as low as 0.5 rabbits per hectare

  • Rabbit control programs have often been ad hoc, lacked strategic prioritisation, and have rarely been initiated in response to threatened species or ecological community recovery

  • Information on the effects of rabbit abundance on pest predators, including prey switching, is limited

  • Rabbit control research over the last five years has predominantly focussed on increasing the effectiveness of Rabbit Haemorrhagic Disease, with several new strains identified, and

  • New approaches and educational tools e.g. online manuals, guidelines, factsheets and economic decision models, have been produced to assist land managers implement integrated control programs.

This TAP incorporates the knowledge gained since the 2008 TAP and has been modified to present priorities in line with the recommendations of the review.

Involvement of stakeholders

The successful implementation of this TAP will depend on a high level of cooperation between landholders, community groups, local government, state and territory conservation and pest management agencies, and the Australian Government. Success will depend on all participants allocating adequate resources to achieve effective on-ground control of rabbits at critical sites, improving the effectiveness of control programs, and measuring and assessing outcomes. Various programs in natural resource management, at national, state and regional levels, can make significant contributions to implementing the plan.

Threat abatement plan for rabbits

This section provides an overview of the threat and management of competition and land degradation by rabbits. The background document (Department of the Environment 2015a) should be referred to for further information.

The threat

The European rabbit (Oryctolagus cuniculus) was deliberately released onto the Australian mainland in the mid to late 1800s. Rabbits dominated two-thirds or 70% of the continent within 70 years (equivalent to approximately 5.3 million square kilometres) (Cox et al. 2013; Bengsen & Cox 2014). This is considered to be the fastest rate of any colonizing mammal anywhere in the world (cited in Williams et al. 1995; McLeod 2004) — with colonisation greatly aided by the use of warrens (which protect them against predators and climatic extremes), their high reproductive rates, and their ability to survive in a wide range of habitats (Williams et al. 1995). They are now one of the most widely distributed and abundant mammals in Australia (Williams et al. 1995); found in all states and territories and many offshore islands, with only the most northerly regions of the mainland thought to be rabbit free. Their exact abundance is unknown and cannot be readily quantified as population sizes frequently fluctuate through factors such as breeding events, mortality caused from biocontrol agents or drought, and availability of resources.

Rabbits inflict substantial damage upon both agricultural and environmental assets (e.g. native flora and fauna, vegetation communities, landforms, geomorphic processes and sensitive sites, and crops) and have been described as Australia’s most costly vertebrate pest (Cooke et al. 2013). For agricultural commodities, this damage has been estimated at exceeding $200 million annually (Gong et al. 2009); for environmental commodities, the value of the damage has not been quantified. The introduction of rabbit biocontrol agents (myxoma and rabbit haemorrhagic disease virus) have helped to reduce both the economic and environmental impacts of rabbits in Australia, although even at lower densities (e.g. more than 0.5 rabbits per hectare), their impact still continues to be severe (Bird et al. 2012; Cooke et al. 2010; Cooke 2012b; cited in Cooke et al. 2013). Direct impacts of rabbits include:

    • Competition with native wildlife for resources (food and shelter)

    • Preventing plant regeneration

    • Overgrazing and general damage to plant species

    • Reversing the normal direction of plant succession

    • Altering ecological communities and changing soil structure and nutrient cycling, leading to significant erosion, and

    • Removal of critical habitat for arboreal mammals and birds, leading to increased predation and reduced reproduction.

Rabbits also have indirect impacts on native flora and fauna, including:

  • Supporting populations of pest predators such as feral cats, foxes and wild dogs, and

  • Promoting growth of introduced and unpalatable species such as weeds.

Rabbits impact over 300 EPBC Act listed threatened species and nine ecological communities. This includes 44 species of fauna (15 birds, 20 mammals, 6 reptiles, 1 invertebrate, 1 fish and 1 amphibian) and 260 listed plant species (Department of the Environment 2015b). A full list of these species is at Appendix A.

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