120 - 145 cm. They are tall and slender birds. Eyes light yellow. Neck and long legs compared to body size, and with respect to any other bird. Plumage dark pink to orange pink, the color may be darker on the rump, head and neck. Outer and central wing feathers black. Bill with black tip, pink to red-orange in the middle and pale yellow at the base near the eye; strongly curved, the inner surface has rows of keratinous plates (lamellae) covered with tiny hairs (cilia). Legs pink with darker joints. Males and females differ in size. Male: 2,800 g. Female: 2,200 g. In juveniles, the bill is straight the first two weeks, then begins to take the characteristic shape and develop the filtration apparatus, the eyes are dark brown. In about four weeks plumage becomes dark gray and between 6 to 10 months, becomes gray-whitish, flight feathers of wings becoming black, bill is pale pink with black tip, legs grayish brown begin becoming to pink. The immature plumage is pale pink, and pink on wings is darker.