Europe and Central Asia
2 Oct 2015

How Belgium is using the internet to find and get rid of invasive alien species

Canada geese are a major invasive alien species in Belgium. Photo: Phil/Flickr
By Wouter Vanreusel

Invasive Alien Species are animals and plants that are introduced accidentally (like by passengers on international flights) or deliberately (like through trade) into an ecosystem where they are not naturally found, spreading rapidly and disrupting the complex and delicate ecological balance in the area.

There are different ways in which these species achieve this. For example, grey squirrels (native to North America but now common in the UK) carry squirrel pox, which they are immune to but has led to huge declines in the population of the native red squirrels. In the last 500 years, species like rats, cats and mice have driven over 70 bird species to extinction.

While reports indicate that only one in 1,000 alien species becomes an ecological threat, those that do can cause enormous damage. Not only do they threaten endemic species with possible extinction, but economically, invasive alien species cost the EU an estimated 12 billion euros a year through destroyed crops, disrupted ecosystems, spread of diseases, etc.  

This is why it is important to find out quickly when a new invasive species arrives and where it settles. While the EU’s regulation on the issue came into force only on 1 January, 2015, the BirdLife Invasive Alien Species Programme and Natuurpunt’s (BirdLife in Flanders, Belgium) online early warning system, which it has been working on since 2012 with Natagora (BirdLife in Wallonia, Belgium) and respective local and national governments have already been working on this issue.

Through this early-warning system – built as an extension of the principal Belgian observation data portal (for Flanders and Wallonia) – volunteers can report the sighting of invasive species with a photo and exact location. Environmental NGOs, governments or private terrain owners can subscribe to get an email when observations of Red and Black List Invasive Alien Species are reported. The major advantage is that data from an already extensive network of observers can be used and volunteers can use their familiar online data portal or mobile app for reporting observations.

The system has already seen success: volunteer data was used in an eradication program for the Ruddy Duck (Oxyura jamaicensis). It is also being used in controlling exotic goose species.

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In order to have adequate estimates for Flanders of all invasive and other so-called ‘summer geese’ (domestic Greylag Goose, Egyptian Goose and Canada Goose, among others), these species are counted at major geese sites during the same weekend in July, when Canada Geese undergo a simultaneous moult of their flight feathers.

Natuurpunt coordinates a network of local volunteers (some 10.000 active observers over the last few years) organised in many local thematic working groups, which form the backbone of data collection from both exotic and native species. This year, approximately 15.000 geese were counted by about 200 volunteers (follow in real-time on the website). Casual observations or counts outside the selected counting areas are also used to complement the dataset.

Natuurpunt takes care of the technical aspects of the data-collection, while the Flemish government (INBO) takes care of the scientific analyses of the data and shares its findings with the national government and the EU. Eradication efforts in Flanders are mainly based on these data. A great example of collaboration between citizen science, NGOs and the government to protect the environment.


Stichting BirdLife Europe gratefully acknowledges financial support from the European Commission. All content and opinions expressed on these pages are solely those of Stichting BirdLife Europe.