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Mute swan (Cygnus olor)

Mute swans are an introduced waterbird recorded in Australia. Where they establish, their heavy grazing of aquatic plants and territorial behaviour can affect wetlands and native waterbirds.

Key facts

Type: Pest animal, bird.

Native to: Europe and parts of Asia.

Established in: QLD, NSW, VIC, TAS, WA.

Best time to act: Survey wetlands year-round and check for nests early in the local breeding season, before eggs hatch, when authorised clutch management can be planned.

Identification

  • A very large swan, with adults about 144 to 158 cm long and a wingspan of 2 to 2.5 m.
  • Adults have white plumage and an orange bill with a distinctive black knob at its base and a black tip.
  • Males are larger than females, but the sexes look similar.
  • Young birds are greyish brown or white and lack the adults’ black bill knob.
  • Look-alike: The native black swan is readily distinguished by its mostly black plumage and red bill.

Where it lives

It uses ponds, lagoons, marshes, sheltered bays and lakes, and often feeds in shallow water.

Why it matters

  • Mute swans eat large quantities of submerged aquatic vegetation and may uproot plants they do not eat, reducing food and habitat available to other wetland wildlife.
  • They can compete with native waterfowl for food and space, defend large territories and drive other birds away.
  • They have been reported to kill ducks, geese and other wetland-dependent birds, and high-density grazing can eliminate plant species from wetlands.
  • They can also attack and injure people, so crews should keep clear of adults guarding nests or young.

How it spreads

  • Introductions can occur through intentional release or escape from parks, estates, zoos or avicultural collections.
  • After establishment, swans can move between wetlands; check nearby suitable sites when monitoring a known occurrence.

Control methods

  • Confirm the identification and seek advice from the relevant state or territory biosecurity or wildlife authority before taking action.
  • Use site-based deterrence and habitat management where suitable, and have capture or removal carried out by trained operators using methods approved by the relevant authority.
  • Where authorised, egg oiling or other clutch-reduction methods may limit hatching, but require repeated effort and monitoring and may not control the population on their own.
  • Monitor treated sites and nearby wetlands for surviving birds, new nests and recolonisation, and report sightings or control outcomes to the relevant state or territory agency.

Site hygiene and welfare

  • Before moving between wetlands, remove attached aquatic vegetation and mud from boats, trailers, footwear and field equipment, and dispose of it away from waterways.
  • Do not transfer water or plant material between waterbodies; clean and dry gear before reuse.
  • Use methods set out in the national model codes of practice and standard operating procedures for the species.
  • Coordinate control with neighbours and the local government biosecurity plan, as isolated effort is quickly undone by reinvasion.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: General biosecurity duty. Not prohibited matter in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Declared animal. Declared animals have legal restrictions, which can cover keeping, moving, selling and releasing them, and landowners may be required to control them.
  • Western Australia: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Not a declared pest. Not a declared pest or prohibited matter in Tasmania. Importing animals is still controlled by Biosecurity Tasmania.
  • Northern Territory: Prohibited entrant. Wildlife that is not native to the NT is a prohibited entrant, so you need an NT permit to bring it in or keep it. Report any wild sighting to the NT Government.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

Sources