The largest duck in the world is the Muscovy duck. Weighing a massive 15 pounds, these ducks are certainly giants. Males are larger than females and can be up to 31 inches long. Muscovys are native to America where they thrive in cold conditions. They are usually found in swamps, lakes, and streams and often roost in trees during the night. Muscovy ducks are black and white and have red wattles around their bill. They eat small fish, reptiles, and insects. Muscovy ducks frequently fight amongst each other and males fight over territory, food, and females. Females also fight but not as often as the males do. Muscovy ducks have been domesticated and domestic birds are generally known as “Barbury ducks”.