Introduced species are often endangered in their ancient homelands

The influx of introduced species and their penetration into newly developed regions often puts pressure on local competitors or spreads new diseases, endangering biodiversity.

“Conservation paradox”
The work of a team led by Viennese ecologist Franz Essl and Lisa Tedeschi underlines “a conservation paradox”: in view of the threat posed by invasive species, and their own, the question now arises whether non-native species can also occur and must be protected in their new home.

Until now it was not known to how many non-native mammal species – in Central Europe these are species such as the brown rat, the mouflon or the mink – this paradox applies.

36 of the 230 invasive mammal species affected
Currently, a total of 230 non-native mammal species have been introduced by humans into new areas around the world and have become permanently established there. The researchers were able to show that 36 of the non-native mammal species are threatened in their native homelands.

Most species threatened in their native range come from tropical Asia, in many cases the result of massive destruction of rainforests and overhunting.

It has been shown that non-native populations can play a central role in the survival of endangered species – especially when there is high risk pressure in the habitat.

New challenges for animal protection
Furthermore, non-native populations can have negative impacts on other species. The main focus should remain on the protection of species in their home range.

However, it is likely that “in the future there will be more species that are threatened with extinction in their native range and have better chances of survival in the new range,” Essl says. This presents nature conservation with the difficult task of weighing opportunities and risks against each other.