Large diving ducks which ride low in the water, Musk Ducks get their name from the strong musk odour produced from a gland on the rump. The male musk duck is easily identified by its distinctive silhouette: large head with bulbous lobe under his bill, and a stiff tail which may be raised and fanned. The female is smaller than the male. Both male and female Musk Ducks are sooty-brown in plumage, with paler brown barring on the body and fine spots of the head. They are paler below. The female also has a much-reduced lobe on the underside of its bill, only visible at a short distance. The bill is dark grey in both sexes and the eye dark brown. Young Musk Ducks are similar to the adult female, but are paler, with a dull yellow tip on bill, and no lobe. Whistling, splashing displays by courting males.