Invasive alien species

Gough Mouse and dead chick (Ross_Wanless)


  • The conservation impact of eradicating invasive species can be dramatic

Invasive Alien Species are animals and plants that are introduced accidently or deliberately into a natural environment where they are not normally found.

They have been the most important driver of documented bird extinctions - implicated in the disappearance of at least 71 species since 1500. This trend continues and over half of the world’s 625 threatened birds are in decline as a consequence of alien threats. The problem is especially acute on islands, where endemic birds often lack adequate defences against introduced predators such as rats and cats.

Despite the magnitude of the problem there is much that can and has been achieved. Over the last two decades there have been considerable advances in eradication techniques, and a number of recent and current island restoration projects attest to the dramatic success that can be achieved given sufficient resources and political will.

Spreading rat-bait using a helicopter in Fiji (S Cranwell)


  • Building global solutions from single-island experience

The BirdLife Invasive Alien Species Programme is preventing the further spread of alien threats by tackling the highest priorities for eradication and control. From local to global, our Partners are working towards their united goals of:

  •  Identifying and promoting priorities for eradicating or controlling Invasive Alien Species, and preventing their spread.
  • Developing and advocating for effective global, regional and national policy frameworks addressing Invasive Alien Species.
  •  Strengthening and developing capacity for designing, implementing and sharing techniques to tackle Invasive Alien Species.
  •  Invasive Alien Species eradicated or controlled, and/or biosecurity established, at the Important Bird Areas and priority restoration sites where they constitute a major current or potential conservation problem.


Fiji Monuriki & Monu Islands (Stuart Chape)


  • Rat-free and recovering

By addressing invasive species, four Critically Endangered birds have been saved from extinction. Black Robin, Seychelles Magpie-robin, Mauritius Parakeet and Rarotonga Monarch were all once reduced to just a few remaining individuals, but now have much healthier populations as a result of concerted conservation efforts and recovery programmes.

In the Pacific, BirdLife Partners are helping to restore island ecosystems by eradicating Invasive Alien Species. Together they have treated 30 islands for five species of introduced mammal across Fiji, French Polynesia, New Caledonia and Palau. In excess of one hundred islands have been surveyed for seabirds and introduced species to help understand the scale of the problem and to prioritise islands for further restoration projects.

Landing bait, Fanna, Palau (Yalap Yalap)

Policy and Science

  • Early successes mean we can be more ambitious

As techniques and materials continue to improve, it is likely that many more island restoration projects will become feasible in the coming years. Consequently, BirdLife International is working with a number of other organisations to compile a scientifically-robust list of the sites that most urgently require invasive species eradication.

Together, we’re advocating for effective global, regional and national policy frameworks addressing Invasive Alien Species. For example, we know that invasive species cause around 12.5 billion Euros worth of damage each year in Europe alone. To address this we’re advocating through the European Parliament for improved legislation address the ticking time bomb.

BirdLife Fiji's Elenoa Seniloli placing rat-bait at a seabird island in Fiji (Rob Chappell)


  • Communities benefit, and their help is essential

The loss of native biodiversity is not the only consequence of Invasive Alien Species there are numerous examples of communities, business and families having major effects on their food security, health and wellbeing.

BirdLife works with local communities to improve their livelihoods and ensure that effective biosecurity is in place to stop re-invasions, and to ensure sustainability of conservation actions for the benefit of nature and people.