Non-native species introduced by humans are one of the main causes of global biodiversity loss—they have directly or indirectly contributed to the extinction of 60% of species globally in recent years. However, a new study from the University of Vienna in Austria and the Sapienza University of Rome in Italy has found that some invasive species introduced by humans to other areas are already endangered in their native areas. The research is published in the latest issue of the journal Conservation Letters.
Globalization has led to the introduction of many plants and animals into new areas. These invasive species often pose serious threats to ecosystems by competing against native species or spreading new diseases. However, some non-native species are threatened with extinction in their native ranges. This raises a “conservation paradox” – should non-native species that are endangered in their native ranges be prioritized for protection, or should they be controlled because of their destructive nature in new environments? To date, the number of species involved in this paradox has not been determined. This study provides the first quantitative analysis of this question, taking one step closer to the answer.
Currently, humans have introduced 230 species of non-native mammals around the world and successfully colonized new environments. The study found that 36 of these non-native mammal species are threatened in their native ranges and therefore fall within the "conservation paradox."
Non-natively colonizing species are often not taken into account when assessing global species extinction risks. However, the study shows that the global extinction risk of some endangered species decreases if non-native populations are taken into account. The researchers note that this result highlights the importance of non-native populations to the survival of endangered species - especially when their native ranges are under high threat pressure.