Objective 3 Develop or maintain alternat

Objective 3 Develop or maintain alternative strategies for threatened species recovery

Objective 3 is focused on providing options where sustained control of cats using standard techniques is not possible or the degree of sustained control is insufficient to enable threatened species recovery. It is likely that any threatened species recovery program will need to incorporate a range of approaches to abate the threat. Also included in this objective is a consideration of the impact of disease transmission from feral cats to native animals and how this impact may be mitigated.

Action 3.1 Eradicate, or control, cats on offshore islands of high, or potentially high, biodiversity value

Action 3.1 emphasises the importance that islands have in maintaining biodiversity. Cat eradication programs have been successful on a number of islands and similar programs on at least two more large islands (Dirk Hartog Island and Christmas Island) are underway. These islands are or will become important refuges for reintroduced threatened species, or have endemic species that are threatened in the case of Christmas Island. This action has the option for sustained control on off-shore islands. This is generally not cost-effective in the long-term but is included to acknowledge that there may be islands where, at the present time, it is not possible (for financial, resourcing or technical reasons) to completely eradicate feral cats. In these situations it may be worthwhile investing in a sustained control program where it enhances the survival of threatened species. Care should be taken to ensure that potential unintended consequences of cat eradication are considered for each island.

Action 3.2 Establish, enhance or maintain biosecurity measures for cat-free offshore islands to prevent incursions

Establishing or maintaining biosecurity measures for islands that do not have feral cats is critical. This may need to be reinforced through state or territory legislation. Action 2.2 addresses issues of provision of appropriate training and information to support and undertake biosecurity.

Action 3.3 Establish and maintain further fenced reserves (“mainland islands”) for threatened species where it is identified cats cannot be controlled to the level required for threatened species recovery

Cats are present almost everywhere in the mainland Australian landscape so there are no natural mainland refuges that can be exploited for threatened species recovery. Instead, where a threatened species population is sufficiently threatened it may be possible to fence an area of habitat with a predator-proof fence. Action 3.3 recognizes predator-proof fencing as an important option for some of the most threatened species that are unlikely to survive without such action. Predator-proof fence designs are now standard but are expensive to build and require significant ongoing monitoring and maintenance. Note though that the ongoing monitoring and maintenance costs may be similar to other ongoing feral cat control methods. There may also be a requirement to manage overpopulation by some species confined to the fenced area.

Action 3.4 Research methods to understand thresholds of cat abundance required to improve survival rates for threatened species heavily preyed upon by feral cats. Research ways in which adaptation by threatened species may improve survival rates

Action 3.4 focuses on further research into alternatives to direct killing or complete exclusion of feral cats that can help threatened species populations to recover. Examples of alternatives may include research into how habitats can be manipulated (e.g. increase the structural complexity of vegetation, introducing plants containing toxins that native herbivores are tolerant to but will impact on feral cats predating upon those species), the use of guardian dogs (e.g. Marrema breed) or trained hunting dogs to protect threatened species populations, and the training or selection of traits within a species to make them more predator savvy. Directly linked to this action is Action 1.7 on understanding feral cat abundance and impact on threatened species in the landscape. As mentioned in Action 1.7, within this research should be an understanding of some feral cats specializing in particular prey (e.g. Dickman & Newsome, 2014).

Action 3.5 Continue research into cat diseases, including Toxoplasma gondii and sarcosporidiosis, their prevalence, ability to transmit to other species (including livestock and humans) their impacts, and ways to mitigate the impacts

Cats in Australia carry a number of diseases that are transmissible to other species. The best known of these is toxoplasmosis, caused by a protozoan parasite called Toxoplasma gondii, of which felids are the only definitive host. In addition, other diseases including sarcosporidiosis that are carried by cats and affect livestock are important to understand because of this impact. Action 3.5 acknowledges that the transmission of diseases from feral cats can have a deleterious impact on social and economic values, as well as biodiversity. While investigating diseases that also impact on livestock and communicating the risk from feral cat-borne diseases to primary producers, it is also important to be mindful that the overall risk to the international disease-free reputation of Australian agricultural produce is not compromised. Through this action, the plan seeks to focus research into the impacts of these cat-borne diseases on other species including threatened species, other native animals, livestock and humans.