Australia, the Americas and India are among the global hotspots where animals are most threatened by invasive species.

Ecologists debate the extent to which biodiversity is threatened by non-native species compared to threats from land-use change and other factors. To explore this, Céline Bellard at University College London and her colleagues analysed the ranges of nearly 1,400 threatened vertebrate species and more than 200 non-native organisms worldwide. The authors also used two databases that list the causes of the animals' decline. They found that 22% of all threatened animals are imperilled by invasive organisms, but none was threatened by non-natives alone.

The invasive organism that threatened the most vertebrates was a lineage of the chytrid fungus Batrachochytrium dendrobatidis, which has killed many amphibians.

Proc. R. Soc. B 283, 20152454 (2016)