Blue Runner ducks are a relatively light duck breed, weighing 3-5 pounds with males being heavier than females. They appear a beautiful blue-gray in color. As with other blue birds, they are difficult to breed because the blue feather color is a recessive trait which is only obtained by breeding parents who are heterozygotes for feather color. This means that of the offspring produced by two parents, only 50% of the progeny will be blue runners. Like other runner ducks, they appear to stand taller than other duck breeds, and make excellent foragers.