Black-bellied Tree Duck- (Warm Climate)The whistling-ducks were formerly known as tree-ducks, but only a few, such as the Black-bellied Whistling-Duck actually perch or nest in trees. They look most like ducks, but their lack of sexual dimorphism, relatively long-term pair bonds, and lack of complex pair-forming behavior more resembles geese and swans.(According to Wild fowl of the world book they will associate well with Fulvous Ducks). Adult Description-Medium-sized duck, Long neck, Long, pink legs, Chest and back Rufus, Face gray, Bill red, Belly black, Large white patch on back of wings. Both Sexes= Length 18.5-20.1 in Weight 23-26 oz Immature Description-Immature like adult, but duller and more grayish brown, with gray bill and feet, and mostly gray belly with some black spots.Nest Description-They usually nest in tree cavity, without lining. Sometimes use a scrape on ground or shallow bowl of woven grasses, with thick vegetation overhead, such as cactus. Uses nest boxes.Nesting Facts-Clutch Size9-18 It is important that these ducks always have open water.