The term Shelducks includes the seven Tadornas that populate the Old World. Shelducks are very elegant, bold and colorful ducks, they inhabit grasslands not far from water. Shelducks are omnivorous and forage in saline waters. Their varied diet includes snails, mussels, marine worms, earthworms, crustaceans, aquatic and terrestrial insects and larvae, and even some small frogs, fish and spawn. They are quite quarrelsome and aggressive and females take active roles in territorial defense and courtship. Pair bonds are strong. Primarily cavity nesters, pairs seek holes, tree hollows, rock crevices, mammal burrows or other sheltered locations to make nests. They have big legs and rounded, flat bills. Some important Shelducks are: Common Shelduck (Tadorna Tadorna), Radjah Shelduck (Tadorna Radjah), Ruddy Shelduck (Tadorna Ferruginea), Australian Shelduck (Tadorna Tadornoides), Paradise Shelduck (Tadorna Variegata) and Cape Shelduck (Tadorna Cana).