Elegant and pristine, swans dress their long necks in white for any occasion. A relative of geese and ducks, swans are the largest members of their family. Found in temperate climates, swans are herbivores, and some migrate. All swans mate for life; however, pairs 'divorce' especially due to hatching problems. Unlike other species, males help build the nest and incubate the eggs. Swan eggs weigh well over half a pound and often are among four to six others.