In recent years, Canada goose populations in some areas have grown substantially, so much so that many consider them pests for their droppings, bacteria in their droppings, noise, and confrontational behavior. This problem is partially due to the removal of natural predators and an abundance of safe, man-made bodies of water near food sources, such as those found on golf courses, in public parks and beaches, and in planned communities. Due in part to the interbreeding of various migratory subspecies with the introduced nonmigratory giant subspecies, Canada geese are frequently a year-around feature of such urban environments.
All Muscovy ducks have long claws on their feet and a wide, flat tail. In the domestic drake (male), length is about 86 cm (34 in) and weight is 4.6–6.8 kg (10–15 lb), while the domestic hen (female) is much smaller, at 64 cm (25 in) in length and 2.7–3.6 kg (6.0–7.9 lb) in weight. Large domesticated males often weigh up to 8 kg (18 lb), and large domesticated females up to 5 kg (11 lb).