Impact of invasive pest animals

Invasive pest animals have significant impacts on Victoria's primary industries, natural ecosystems, human and animal health and are one of the main threats to biodiversity in Australia today.

On agricultural land

The presence of invasive animals on or adjoining farmland may cause lost agricultural production through:

  • predation on livestock
  • grazing on crops and pastures
  • spreading weeds
  • contributing to erosion
  • land and water degradation

Control measures are often expensive and divert resources for management from everyday production. There is also a risk that they may introduce exotic disease and parasites to stock.

In 2009, the Invasive Animals Cooperative Research Centre published a report (The economic impacts of vertebrate pests in Australia) that estimated the direct national annual economic impact of 6 invasive animal species (wild dogs, foxes, mice, pigs, rabbits and starlings) of $743.5 million for both agricultural losses and expenditure on management, administration and research.

Environmental costs

Invasive animals prey on native wildlife and can out-compete and displace other native animals by competing for harbour, food and water resources. They can cause detrimental effects on landscapes by spreading weeds and contributing to soil erosion, water degradation and loss of biodiversity. They may also carry and spread exotic diseases that can be transferred to native fauna.

Estimates of the environmental loss in Australia as a whole are not possible because of a lack of data. Therefore, this annual total underestimates the impact of invasive animal species in Australia.

Social impacts

The social impacts of invasive animals may include:

  • nuisance behaviour
  • destruction and fouling of building and infrastructure
  • disruption to farm activities
  • distress associated with loss of production
  • livestock predation

Invasive animals can carry exotic diseases to Australia or act as a reservoir for diseases that can spread to humans.

Approach to management

Agriculture Victoria uses a science-based approach along with Integrated Pest Management (IPM) principles to underpin our invasive animal management programs and management recommendations.

The department places a priority on investing in the prevention and eradication of newly emerging 'exotic pest animals' and the protection of assets from the impacts of 'established invasive animals'. Humane animal welfare outcomes are also at the core of our work.

Who is responsible

We all have a role to play in invasive animal management. By working together, government, industry and the community can best reduce the impact of pest animals in Victoria.

In Victoria, invasive animals are classified under the Catchment and Land Protection Act 1994 (CaLP Act) as to their threat to agriculture and the environment. Generally, those that are declared as 'prohibited', 'controlled' or 'regulated' may be considered 'exotic pest animals' and the department takes the lead to control these animals.

Land owners have a responsibility to control those declared as 'established' invasive animals.

Read more about invasive animal classification in Victoria.

Exotic pest animals

Agriculture Victoria is the lead agency for management of exotic pest animals on public and private land in Victoria. These animals are typically not established in the wild in Victoria. If these high-risk species were allowed to establish in the state, they would present a threat to our economy, environment and social values. The most cost-effective management of these exotic pest animals is to prevent their entry into Victoria, followed by early intervention to prevent their establishment.

Our role includes the management of new outbreaks (or incursions) of these exotic pest animals. Incursions can be the result of stowaways on transport vehicles and vessels, through animal smuggling, through the deliberate releases of animals and through animals escaping from captivity.

Wild rabbit sitting in grassEstablished invasive animals

Land owners have a legal responsibility to control declared established pest animals under section 20(1)(f) of the CaLP Act: 'In relation to his or her land a land owner must take all reasonable steps to prevent the spread of, and as far as possible eradicate, established pest animals.'

More information on the management of this category of pest animal can be found on the Established invasive animals web page.

For more information on your responsibilities as a landowner, see Legal responsibilities for managing invasive species.

Things to consider before you begin

Wild fox standing in a field of daisies Invasive animals

The first step is to ensure you are dealing with a declared established pest animal.

The most effective way to control pest animals is by using a variety of techniques  — in a coordinated fashion  — implemented at the landscape scale.

Before beginning a management program you should consider what the impacts of the pest animals are and the aims of your control program. You should talk with your neighbours so that you can coordinate your control measures to achieve better results.

You should form a detailed Integrated Pest Management plan that encompasses:

  • other invasive plants and animals in the area (you may achieve better results by focusing on a number of species)
  • monitoring (allows you to determine the areas of pest animal activity, pest animal density and provides a baseline to evaluate project success)
  • implementation (what control measures you will use to exploit the pest animals biology at various stages of the life cycle)
  • prevention (what control measures you can use to prevent pest animal impacts and re-invasion)
  • evaluation and follow-up (has your plan worked?, what can be changed to make it more effective?, what follow up do you need to do to ensure that the impacts are managed in the future?)
Page last updated: 09 Sep 2021