Aging a Common Loon Chick by its Plumage
This year’s Common Loon chicks are now roughly two months old. Even without being aware of when it hatched, you can estimate the age of a chick by looking at its feathers. Their color and type (down or contour) can give you a good idea of how many weeks old it is. Common Loon chicks are born covered with sooty-black down. By the time they are three weeks old they have replaced this natal down with a second (gray-brown) down. Juvenal feathers start appearing soon thereafter, replacing the down — the age of a chick can be estimated by the amount of down that remains. By eight weeks of age the chicks have just small tufts of brown down remaining on their head and neck (see photo). By nine weeks of age their entire body, including their head and neck, are covered with smooth, gray contour feathers and there is no sign of down.