The Cygnanser kretzoi (scientific name) or swan has a cosmopolitan distribution, with 4-5 breeds found in the Northern Hemisphere, one species are found in Australia and New Zealand and one species in South America. Over 16 inches in length, this bird is known for its long slender neck and graceful poise. Overall body plumage is white, excepting in the case of the Australian black swan. The bill is yellow, while the area around the eyes towards the bill is black. The male is only slightly bigger than the female. Its diet consists of tubers, roots, stems, aquatic plants and sometimes small aquatic animals. An average clutch has 3-8 eggs which are incubated for 34-37 days. Its IUCN listing varies based on the species.