Invasive species are animals or plants which establish themselves in an area different from their natural range. So, when talking of exotic invasive fauna we are referring to species of animals which have been transported and introduced by humankind (either intentionally or not) into a habitat which is not its own and has managed to survive, establish itself and thrive.
Exotic invasive species are a potential danger for the original eco-system, for both the flora and the native fauna. This is especially true when considering the competition for resources and ecological niches, the introduction of new diseases, depredation, changes in the trophic chain, etc. Thus causing a serious negative impact such as significant changes in the composition, the structure or the processes of eco-systems.
Exotic animals are introduced by man, either accidentally or not, into a territory which is not its own. Man is responsible for removing the animals from their native habitat and introducing them into a foreign one. The animals are transported and sold for use by human beings, however, they often end up in the local countryside, either because they have escaped, been released intentionally or have been abandoned.
Not all species are invasive, neither does the term invasive refer to any particular place or time, there are many factors at play. An animal that may be invasive in Spain, may not even survive in another country, where environmental factors are different.
It is estimated that only 1 in every 10 animals captured for trade from its natural habitat survives. This is due to the method used to capture them and the deplorable conditions of transportation.
In Spain Law 42/2007, 13th December, on the Natural Heritage and Biodiversity, defines an exotic invasive species as “one which is introduced or settles into an ecosystem or natural/semi-natural habitat and is an agent of change which threatens the local biological diversity, either because of its invasive behaviour or because of the risk of genetic contamination”. The same law established that the competent authorities must prohibit the introduction of foreign species when they are considered likely to compete with local species. It also established, in article 61.1, the Spanish Catalogue of Invasive Exotic Species, in which all species which present a threat to local diversity in Spanish territory are supposed to be included. Lastly, in order to regulate said catalogue Royal Decree 630/2013, 2nd August, was passed.
How are exotic invasive species controlled? The best way would be prevention. However, it is very difficult to predict which species are likely to settle and invade each ecosystem. Any species introduced is likely to escape to natural habitats and settle. Therefore it is of great importance to control imports of allochthonous animals.
Animal rights organisations like ourselves argue that restricting trade in foreign wild animals is one of the best ways to prevent this and that it is a solution to preventing the introduction of more invasive species. In spite of this the authorities choose to act once the problem has been detected, which unfortunately is often when the problem is already too big. If the problem were detected earlier, a rapid response would be sufficient. The authorities choose to eradicate the invasive species, although that is not always possible, and it is only then that they go on to control the invasive population. This way at least ecological and socio-economic damage is kept to a minimum in their eyes. They completely ignore the animals’ right to live and be respected.