Abstract
I observed foraging behavior of waterfowl at a pond overgrown with fanwort (Cabomba caroliniana), a non-native aquatic plant. I made observations at Shimizu Pond, located in Mito-City, Ibaraki Prefecture, Central Japan, during April 2011 through March 2012. Bewick’s Swans, Whooper Swans, Gadwalls, Falcated Ducks, Eurasian Wigeons, Mallards, and Coots foraged actively in the bed of fanwort. I observed that the birds mainly foraged stems and leaves of fanwort in winter, but that some species of duck did not appear to consume fanwort.
