Who leads and who follows? The female duck always makes the choice for the breeding area because she is homing to the site of her birth or a site where she successfully hatched a nest. There is very little evidence indicating which sex determines the wintering site. In most duck species, males and females will go their separate ways after the breeding season, each returning to their respective wintering site from the previous year. Female ducks tend to winter farther south, and those that were successful at raising young arrive much later than males.
Ducks vary in color, from the drab browns and tans of a mallard hen to the strikingly colorful wood duck drake to the subtly beautiful king eider. This incredible variation in color is the result of plumage coloration. And depending on the color, the mechanism behind it may be different. Feather color results from either pigment within the feather or from the very structure of the feather itself. Colors like brown, yellow, red, orange, and black are the result of pigments. Some pigments, such as melanin in the black wing tips of snow geese, provide feathers with added resistance to wear. In fact, if you take a look at the primary wing feathers of most waterfowl, you'll find that the tips and/or outer edges are darker than other parts of the wing for this very reason.
On the other hand, iridescent greens, purples, and blues are produced by the way light is reflected and bent within the structure of the feather. Selective absorption and reflection of light results in the glistening blues and purples and greens in the speculum of a dabbling duck, and the green head in a . . . well, greenhead. These colors actually change in appearance depending on your angle of sight. Look at these same feathers in a shadow, however, and it is as if someone flipped off the switch. Without direct light, these feathers look black.