Margaret A. Wissman, DVM
Posted: May 14, 2013, 1:45 p.m. PDT
Birds need to be exposed to the ultraviolet light ranges for optimum health.
Are the lights sold at home improvement stores, which are advertised as "natural sunlight,” good to use as lighting around my birds? They don’t specify if they are full-spectrum.
To receive the benefits of the ultraviolet portion of the light spectrum, the light must specify that it is a full-spectrum light, not one that simulates natural sunlight. Natural light means that it provides near-perfect color rendition for maximum clarity so that the colors appear real, as they would outdoors under natural sunlight. Some natural sunlight bulbs do emit the ultraviolet portion of the spectrum, so read all the literature that comes with the bulb to see if it mimics natural sunlight or if it also emits ultraviolet light.
All birds benefit from receiving natural sunlight — light that is not filtered through glass or plastic. The best way to provide your pet bird with the necessary ultraviolet light for optimal health is to allow it some time outside, in the safety of a pet bird cage with appropriate shade and supervision, so that it can receive natural sunlight.
The uropygial gland (the preen gland found at the base of the tail on the back of many species of bird) produces vitamin-D precursors, which are spread on the feathers during normal preening. When the bird is exposed to ultraviolet light (the UVB portion), the precursors are converted to active vitamin D3, which is then ingested when the bird preens again. Vitamin D3 is necessary for a bird to properly absorb and utilize calcium. People manufacture vitamin D3 when we are exposed to ultraviolet light, as well, but we synthesize it in the skin by using an enzyme to convert 7-dehydrocholesterol into active vitamin D3.
Studies performed on poultry showed that they could synthesize sufficient vitamin D3 to prevent rickets (bone deformities from inadequate calcium) and maximum growth by exposure to natural sunshine for 11 to 45 minutes per day. Baby psittacine birds still being hand-fed are provided with cholecalciferol (vitamin D3) in commercially prepared hand-feeding formula, so natural sunlight should not be necessary for their optimal growth and health. (Baby birds in a psittacine nest, which is usually in a hollowed-out tree trunk, would not receive any natural sunlight until fledging).
For adult pet birds, especially African species (such African greys, Poicephalus parrots, etc) that seem to be more sensitive to calcium problems, ideally they should be provided with an hour of natural, unfiltered sunlight a few times per week, but this is not always practical or possible. In those situations, full-spectrum fluorescent bulbs can be placed near the birds to provide them with the ultraviolet portion of the spectrum. For optimal effectiveness, the bulb must be placed at the recommended distance from the bird and replaced at their recommended intervals.
All birds benefit from exposure to natural, unfiltered sunlight or from full-spectrum light bulbs that emit the correct ultraviolet spectrum. Bulbs that emit simulated natural sunlight enhance the colors of birds’ feathers, but one must ascertain whether those bulbs emit light in the ultraviolet portion of the spectrum.