Light also affects molting. In some cases birds will molt continuously at a low level. When the feathers mature completely, the blood supply will dry up and the sheath will slowly flake away, exposing the new feather. Your bird's behavior is also affected by light. Intensity of light dictates the time at which birds go to roost, and when they emerge in the morning.
Diurnal species depend on daytime light intensity to accomplish foraging and hunting.
In cases of display behavior, light is needed for flaunting plumage, in order for males to attract females. While in some climates it's not feasible to keep your feathered friend outdoors, this does not diminish the importance of light. As an alternative, full-spectrum artificial lights have been developed to simulate natural sunlight. These lights provide the full-color and balanced ultraviolet spectrum of natural outdoor light, at a reasonable cost. The most popular type is Vita-Lite, a general purpose florescent lamp which can be purchased at most hardware stores.