The common goldeneye is called so (quite obviously) because of its strikingly amber eye that is accentuated by its glistening green-black (male) or brown head (female). This medium-sized duck is a bit smaller than a mallard at approximately 18 inches in length and weighing one to two pounds. From an aerial perspective, adult males are all black with a black head and back, but nearly all white on the sides with a notable white circle on their cheeks. Adult females have an entirely brown head with grayish brown body plumage. Fun fact: The eyes of the common goldeneye change drastically over its adolescence, from dark purple to blue to greenish blue to pale green, then finally to bright amber yellow when they reach adulthood.