During the summer months, robin parents work from sunrise to sunset raising two to four broods. Newly-fledged robins need time to grow and learn. Dad teaches them to forage for food, recognize dangers, and roost in trees with other robins. Few robins start new nests after late July. Caring for babies takes so much time and energy that migratory birds can do this for only a short time in their annual cycle. As the adults' hormones decrease and territorial feelings diminish, robins sing less and the chorus quiets.