The great cormorant (Phalacrocorax carbo), a large water bird, has a long neck, giving it something of a primitive, reptilian appearance. Adults are black with a bluish or green sheen. At the base of the bill is an area of bare, yellow skin surrounded by white. During the breeding season there is a white patch on the thigh, and throughout the year a variable amount of white occurs on the crown and back of the neck. Juveniles are dark brown and have a white area on the underparts. A variety of deep vocalisations are produced in colonies. The name cormorant is derived from the Latin 'corvus marinus', which means 'sea crow'.