An estimated 800 red-necked wallabies descended from escapees in the 1960s now dominate the Ballaugh Curraghs marshland on the Isle of Man, having browsed away rare understorey plants such as royal fern, common wintergreen, ivy, angelica and meadowsweet, and displaced a winter roost of more than 100 hen harriers. Liver fluke has been found in roadkill wallabies, while toxoplasmosis risks and vehicle accidents involving swerving drivers are reported, alongside concern for TT motorcycle racers. The Manx Wildlife Trust is drafting a management policy addressing welfare, economic and ecosystem concerns.