A useful substitute may be a full-spectrum fluorescent bulb with the fixture close enough to the bird to provide the UV spectrum. Ideally, the bulb should be within a foot or two of the bird to provide benefits. Remember that the capability of the bulb to produce UV does not last for the life of the bulb. The bulb can still be used for general lighting purposes after it is no longer producing full-spectrum light. Certainly, we must not forget the potential hazard of excessive UV exposure, such a skin cancer and eye disease.
All animals are dependent on light to some extent, but birds are particularly sensitive to it.
Birds deprived of sunlight may develop a variety of problems, including poor nutrient absorption, vitamin D deficiency, feather plucking, and disruption of mating and breeding patterns. Many bird owners place their pet's cage near a window or other light source, but that may not be enough to cure the problem, since glass can act as a filter, reflecting instead of transmitting certain portions of the spectrum. Dr. John Ott's research into the light needs of people, plants and animals led to the invention of full-spectrum lighting, a term coined by Ott. The poultry industry has already discovered that the benefits of providing full-spectrum lighting include increased egg production, larger eggs with stronger shells, and healthier birds. Pet bird keepers know that their companions need fresh air, proper foods and a constant supply of clean water in order to survive and thrive.