Muscovy Ducks are enormous ducks frequently kept in native huts to control insects. They are quite tasty, and females are good layers with long seasons. Due to distinct basal knobs, humped crowns and hanging nape-tufts, drake Muscovy Ducks are uniformly iridescent black with strong metallic bronzy-green and purple reflections and are characterized by ugly red facial warts and huge caruncles. An erect, bushy topknot is characterized of both sexes, but the crest is larger in drakes. While wild birds are quite beautiful, and lack the coarseness of their domestic relatives, the two forms can be confused, because domestic ducks are frequently kept at liberty by country people, and it can be difficult to determine whether or not local ducks are feral. Domestic may hybridize with wild birds, but pure Muscovy ducks are usually wary and rarely associate with other waterfowl. They are tropical forest-dwelling birds and are linked to lowland and swamps, slow-flowing rivers, lakes and lagoons. They are not very vocal but the soft blowing hisses of angry drakes can be loud. Their noisy wingbeats are slow but they can fly fast for such cumbersome ducks. Their diet consists of crabs and fish and have fondness for termites. Generally active in the evening and early in the morning, they readily perch on high, bare tree branches so as to view their surroundings. Their breeding season can be variable. The essentially polygamous males do not form pair bonds, and normally associate with females only long enough for mating. Copulation is quite brutal. High hollows in gallery forest trees near slow-flowing rivers are usually sough, but females also nest between branches as high as 60 feet in palm tree crowns, abandoned hawk or Jabiru stork nests, and less frequently on the ground in dense waterside vegetation. The domestic form nests on the ground. Ducklings dive with ease, but some fall prey to carnivorous fish.