Pets and Pests – biosecurity in Australia

Practitioners from a range of disciplines and countries spoke about emerging threats and new technologies being developed and applied in the field of vertebrate pest management. Pest species and their associated management challenges discussed at the conference ranged from old foes including wild dogs, feral horses, feral cats, camels, goats, foxes, Indian mynas, starlings, pigs, deer, rabbits, carp, rats, wallabies and possums to new arrivals such as smooth newts in Victoria and black-spined toads.

The arsenal of weapons and techniques currently being used in the fight to control vertebrate pests includes sniffer dogs, drones mounted with videos or thermal-imaging cameras, bait traps, poison baits, remote surveillance cameras, audio-recorders, leg-hold traps, cage traps, aerial and ground shooting, aerially deployed thermal sensors, legislative controls, immuno- contraceptives, biocontrols (myxoma virus, rabbit haemorrhagic disease in rabbits and herpes virus in koi carp), scat markers, Judas animals and GPS collaring, visual and olfactory lures, instant-kill traps, toxin-delivery traps and mobile-device apps.

Community-based action on invasive species

There was recognition of the value and increased need for community-based action to tackle invasive species.

The impact of declining government resources coupled with an increasing decline in numbers of farmers in rural areas was recognised as a huge challenge for the future of effective pest management. A number of speakers drew attention to the fact that we cannot rely on government to fund invasive species control in the future. Effective engagement of communities is seen as essential but will necessitate reducing institutional impediments to community-based control efforts (such as liability issues, expensive accredited training requirements and land-use laws).

Climate change was also raised as an important issue that will likely require adaptations in the principles and practices used to manage vertebrate pests. Changing climate variables, including temperature and rainfall, are driving native species distribution changes and ecosystem compositional changes. Vertebrates, both native and non-native, will be displaced into (or invade) regions where they do not currently occur.

New emerging pests: Reptiles

Reptiles were identified as the new emerging pest of concern for Australia, constituting half of all new vertebrate incursions in Australia in the last decade. They represent a particular challenge due to their cryptic behaviour and unrivalled escape abilities, coupled with a lack of well-developed detection techniques. Body size, clutch size and colouration patterns can influence the likelihood of a species being transported (stowing away) and/or being detected once it has escaped. No invasive reptile species has ever been successfully eradicated anywhere around the world.

Perhaps surprisingly, whilst small numbers of vertebrate pests do continue to arrive in Australia, a greater threat is created by species native to and already in Australia spreading beyond their natural range. Increased trade in reptiles (both legal and illegal) has facilitated this. The theft and escape of native and exotic captive reptiles from both private and public collections represents a very high risk to biosecurity in Australia.

Early detection of reptile incursions remains the best option for preventing new invasions. The Department of Primary Industries in Victoria has developed pre-incursion resource documents to enable rapid identification and response upon the discovery of a range of high- risk exotic invasive species.

Just as importantly, new strategies are required that directly involve the breeders and keepers of reptiles, in order to successfully prevent new invasions of native species beyond their natural range.

Rabies coming soon to our shores?

Wild dogs and their management featured prominently in discussions, with concern raised about the alarming prospect of canine rabies arriving shortly on Australian shores. Canine rabies, a fatal viral zoonosis (infectious disease transmissible to humans), is reportedly less than 300km from Australia’s mainland and continues to spread eastwards through the Indonesian archipelago. Rabies is transmitted from dog to dog and then via dog bites to humans. Cruising yachties (round-the-world recreational sailors) with dogs on board who make informal visits ashore with their dogs present an imminent threat to biosecurity along Australia’s largely unpatrolled northern border.

Canine rabies will have major implications not only for Australian pest management but also for pets and people, as interactions between infected wild dogs, hunting dogs, ‘town dogs’ in remote communities and pet dogs spread the disease. The arrival of canine rabies in Australia will require changes in the way pet dogs and wild dogs are managed and will have massive implications for public health.

Incursion response planning is under way, including the use of modelling to understand how canine rabies will move through Australian ecosystems and to inform the development of effective rabies management plans and increase chances of containing outbreaks.

Cat Management Fail – Intervention required!

Despite awareness in the community of the potential harm to native wildlife and nuisance to neighbours that pet cats can cause when allowed to roam free, the majority of cat owners continue to allow their cats to roam.

The effective control of pet and stray or unowned cats is central to the management of feral cats and the cat population as a whole.

The introduction of cat control legislation, together with education programs to promote responsible cat ownership, are not enough to achieve effective pet cat control. It is now understood that a large-scale nationwide shift in human behaviour is required. This is a long-term task that will take sustained effort.

To address this issue a new project is under way, by University of New England PhD candidate Lynette McLeod in conjunction with the Invasive Animal Cooperative Research Centre (IACRC), to develop an ‘intervention strategy’ to improve the effectiveness of pet cat management. Lynette’s project is part of a larger research component of the IACRC which is developing ‘best practice’ communication strategies by evaluating behavioural sciences to create interventions to engage, educate and change attitudes and behaviours towards pest management. In particular, Lynette’s project will investigate the potential and practicality of community-based social marketing to develop interventions to improve the effectiveness of cat management programs.

Community-based social marketing emphasises direct contact among community members and the identification and removal of barriers to a behaviour, since research suggests that such approaches are often most likely to bring about behaviour change. (An example might be identifying why is it that people do not contain their cats and what needs to be done to ensure that they will). Community-based social marketing also uses a set of ‘tools’ which have been identified as being particularly effective in fostering change. A program is usually piloted in a small segment of the community and refined until it is effective. It is hoped that the Tasmanian community may be selected for a pilot study.

Meg Lorang