Figure 1

Examples of high-impact invasive species in Europe. (A) grey squirrel (Sciurus carolinensis), native to North America, ^© Jeschke; (B) Canada goose (Branta canadensis), also native to North America, ^© Jeschke; (C) giant hogweed (Heracleum mantegazzianum), native to the Caucasus region, ^© Denholm, NJ Dept of Agriculture, Bugwood.org; (D) round goby (Neogobius melanostomus), native to the Caspian, Black, and Azov Seas, ^© Aquatic Systems Biology Unit, TUM; (E) common ragweed (Ambrosia artemisiifolia), native to North America, ^© Bodner, Southern Weed Science Society, Bugwood.org; (F) signal crayfish (Pacifastacus leniusculus), native to North America, ^© Aquatic Systems Biology Unit, TUM.