The Common Merganser (Mergus merganser), also known as a the gulaund or goosander, is a large-sized duck, which is distributed over Europe, North Asia and North America. It is most common on lakes and rivers. Its nests can be found in treeholes. There are three subspecies M. m. merganser, the Goosander of Europe M. m. orientalis, Central Asian Common Merganser M. m. americanus, American Common Merganser Males and females are easily distinguished, since the male merganser has a dark green head,… (More on Goosander)