Are threat status and invasion success two sides of the same coin?
Global change increases both the number of threatened species and the impacts of invasives. These two problems are sometimes assumed to be opposite sides of the same coin, with invasive species having the opposite characteristics of endangered species. However, the validity of this assumption has never been tested. We analysed 20 life-history and other traits of all European and North American freshwater fish and birds. For these 1813 species, we compared the determinants of invasion success and IUCN-threat status and found that traits favouring invasion are not simply the opposite of those that favour endangerment. The size and life history of species are correlated more strongly with threat status than invasiveness. On the other hand, association with humans is the best predictor of invasiveness but is not correlated with threat status. Thus, the rise of invaders is caused by different aspects of global change than the imperilment of endangered species.