In the winter, both sexes have similar appearance. Other characteristics include large gray feet and a concave bill, which is gray in the winter but will change to a blue-gray in the spring for males. Males also display different colors in the spring, changing to a red-brown chest, rump and flank. The ruddy duck is generally a vegetarian but will also eat animals. The diet includes pond weeds, stems, and leaves, and larvae of midges.
Food is acquired by surface dives.
The shape of the body along with the feet located at the extreme rear, make the duck an excellent under water swimmer. Reproduction Reproduction begins with an elaborate display by the male in front of the female. The male will swim by her several times with his tail raised in a fan. He will then slap his bill against his chest producing a drumming sound and creating bubbles from beneath his chest. This display is more for territory declaration than anything else since the female is seemingly unimpressed.