Hooded Mergansers have a crest at the back of the head which can be expanded or contracted. In adult males, this crest has a large white patch, the head is black and the sides of the duck are reddish brown. The adult female has a reddish crest, with much of the rest of the head and body a greyish-brown. The Hooded Merganser has a sawbill but is not classified as a typical merganser. (source: Wikipedia)