Thereafter growth is more gradual. As they grow, pheasant chicks' plumage changes. Within a few days of hatching, natal down is replaced by drab juvenile plumage similar in both sexes. The primaries, or flight feathers, are the first real feathers to develop, and by the end of its first week, a chick is capable of short flights. Chicks undergo a virtually continuous molt during the first summer, and begin to replace their juvenile plumage with adult or postjuvenile plumage at about four weeks.
Young roosters begin to show colored feathers on their breasts and necks at eight weeks.
Adult hens also molt during this period. They are at their lowest weight of the year after egg laying and incubation, and must use any reserve energy to grow new feathers. There is some evidence that many hens die from this stress. In fact, there are indications that summer hen mortality may exceed winter mortality. Adult roosters molt in late July and early August and become quite secretive.