Worldwide ant invasions under climate change

Many ants are among the most globally significant invasive species. They have caused the local decline and extinction of a variety of taxa ranging from plants to mammals. They disturb ecosystem processes, decrease agricultural production, damage infrastructure and can be a health hazard for humans. Overall, economic costs caused by invasive ants amount to several billion US $ annually. There is general consensus that the future distributions of invasive species are likely to expand with climate change, however this dogma remains poorly tested. Here we model suitable area globally for 15 of the worst invasive ant species, both currently and with predicted climate change (in 2080), globally, regionally and within the world’s 34 biodiversity hotspots. Surprisingly, the potential distribution of only five species was predicted to increase (up to 35.8 %) with climate change, with most declining by up to 63.3 %. The ant invasion hotspots are predominantly in tropical and subtropical regions of South America, Africa, Asia and Oceanic islands, and particularly correspond with biodiversity hotspots. Contrary to general expectations, climate change and invasive ant species will not systematically act synergistically. However, ant invasions will likely remain as a major global problem, especially where invasion hotspots coincide with biodiversity hotspots.