It is up to Member States to select the ‘appropriate’ measures to eradicate or control Invasive Alien Species, very often resulting in methods that cause pain and suffering
Invasive Alien species (IAS) are species which threaten or have a negative impact on biodiversity and the ecosystem of the host country. They come into Europe for a number of reasons: to be kept as pets, farmed for fur, or used for hunting or fishing.
When animals are introduced into a new environment, they may not be faced with the limiting factors normally found in their native habitats, such as predators or food scarcity. Able to spread and multiply, they are at risk of becoming invasive in their new habitat, creating an imbalance with the endemic species, transmitting diseases to them or competing for resources.
Once invasive alien species have been introduced to a new environment, controlling their spread and limiting their impact on the environment and native species may become necessary. In doing so, animal welfare must be at the forefront. An invasive animal still has the same capacity to experience pain, stress and suffering as a non-invasive one and their welfare must be considered within management decisions.
As Member States are allowed to select the ‘appropriate’ measures to eradicate, control or contain invasive alien species, this can result in methods being used that cause pain, suffering and distress to target and non-target animals alike. Some European countries, for example, use drown traps to control muskrat populations. Drowning can take more than three minutes, and the inhalation of water is an extremely stressful experience.
Few efforts have been made so far to develop effective non-lethal methods, although research has been done into promising ideas such as the fertility control of grey squirrels in the UK, which lured grey squirrels using chocolate spread to ingest an oral contraceptive. However, even these methods require thorough analysis of their negative effects, as there may be short- or long-term impacts on animal welfare and on non-target species. One Australian study showed that short-term effects may include physical side effects of an injection or implant, while long-term effects can be loss of fitness or altered behaviour.
Some examples of animals that have become invasive alien species in Europe include the red-eared slider turtle and the American grey squirrel, which entered as exotic pets.
The grey squirrel's threat to the native red squirrel in the UK since its introduction in the 19th century is well documented. The estimated population of grey squirrels in 2014 was 2,520,000, heavily outweighing the estimated 287,000 red squirrels.
Ring-neck parakeets, also introduced via the pet trade, are threatening native species such as bats in Spain and local bird species in England, where they are also a threat to crop growth. The cost of the IAS management in the EU is estimated to be at least €12 billion per year.