Germany is a paradise for many animal species that have been introduced: they have no predators and can spread unhindered. According to a study, however, this is becoming more and more of a problem. The North American bullfrog and the brown tree snake in particular cause enormous damage.
According to a recent study, introduced animal species have caused billions of euros in damage worldwide in recent decades. Between 1986 and 2020 alone, fighting invasive species and the crop losses they caused cost the global community around $17 billion, reports a team of scientists in the journal Scientific Reports.
Accordingly, the North American bullfrog and the brown tree snake are by far the largest cost drivers among the alien animals. “The damage is very likely much higher,” estimates lead author Phillip Haubrock from the Gelnhausen branch of the Senckenberg Nature Research Society in Frankfurt. He therefore suggests significantly increasing “measures to limit the global transport of invasive amphibians and reptiles” while paying more attention to impending new invasions.
Invasive species can severely disrupt the biological balance in their new environment. Since they often have no predators there, they can spread almost unhindered. The brown tree snake, for example, was introduced to the western Pacific island of Guam, reproduced rapidly and wiped out many species of birds and small animals.
This, in turn, has an impact on the island’s flora because the birds are important for seed dispersal. According to the German Nature Conservation Union NABU, the American bullfrog was abducted or actively resettled around the world in order to gain frog legs, for example. “In all new areas of occurrence, it is a major competitor to the native amphibian and other animal species.”
For their study, the researchers said they evaluated figures from the “InvaCost” database, which compiles the economic costs of species invasions. The data comes from peer-reviewed articles, documents on government, academic and NGO websites.