light, lighting, vitamin D, ultraviolet, ultra violet, health, birds pets pet bird parrots parrot magazines ezines e-zines

light, lighting, vitamin D, ultraviolet, ultra violet, health, birds pets pet bird parrots parrot magazines ezines e-zines

Winged Wisdom Pet Bird Magazine, Pet Bird Ezine
Pet Bird
Magazine, Ezine

January 2000Magazine

As we move forward into the 21st Century, the lives of our birds are understood better than at any time before. Consider that just a scant 20 years ago, avian medicine was so poorly understood that many vets refused to treat parrots and other large birds. We have seen the advent of the pellet diet, while still far from perfect, offer much better nutrition than has ever been available in the past. Cages, toys, and other environmental considerations have jumped light years ahead in terms of construction, safety, and variety.

Providing proper lighting is something that also has come a long way into entering the consciousness of the birdkeeping public. While often unsure of the reason, many responsible bird owners have made allowances which provide their feathered charges with either additional sunlight, or a source of full spectrum lighting. It is in this area that several old, and a few new myths and misconceptions are to be found. Entering the new millennium, it is time to discard old concepts and move forward. To be found in this article are three of the most hotly debated issues of lighting today. Read them at the risk of changing your mind about what you "know" about full spectrum lighting.


Many people are stuck in a rut when it comes to thinking about lighting for their birds. They think that the main purpose of full spectrum lighting is to provide their birds with a source of Vitamin D. Some people think that Vitamin D is part of the rays in sunshine. Therefore, common wisdom has said that given a few hours a day of full spectrum light, birds will be healthful and happy. The truth of this matter is simple: birds require a regular photoperiod for health, and receive all of the Vitamin D they require from balanced dietary sources. The rest is a myth.

To properly understand the truth of this, the reader must bear along for a few moments of technical discussion, and examine exactly how Vitamin D is synthesized in animals. In the body, the liver manufactures a chemical known as 'precursor D' (7-dehydrocholesterol) a "good" cholesterol. This substance is released into the bloodstream, where in humans, it is exposed to the middle range of UV through the skin, becoming "previtamin D". This is sometimes confused with D2 (calciferol), a form of the vitamin which is found in plant sources. In most birds, the preen gland collects the raw pre-D from the bloodstream, and concentrates it in the gland oils. These are then exposed to sunlight by spreading on the feathers during preening. The bird then ingests the UV exposed material when it preens again, and the oils enter the body again as previtamin D.

The natural temperature of an organism then rearranges this substance further, forming a weak D3, or cholecalciferol. This is what is generally available as a dietary supplement in fish liver oils. To become fully active as Vitamin D, the liver and the kidneys make other changes in the chemical, resulting in true Vitamin D3 (1,25-dihydroxycholecalciferol). In any warm blooded animal, once a source of calciferol or cholecalciferol is introduced, UV of any sort no longer plays a role in the synthesis. This is evidenced by animals who are nocturnal, fur bearing, or burrowing, and receive no UV exposure. They acquire proper levels of Vitamin D from dietary sources.

It is the same thing with birds. Several species of tropical birds, including African Grey's and Red Front Macaw's have underdeveloped or non-functioning preen glands. Other species, such as Cockatiels, Conures, and Budgies obtain the vast majority of their intake in the form of calciferol. This calciferol is found in the fresh grains which form the bulk of these birds diets. From this perspective, any birds which receive a balanced diet, rich in calciferol or cholecalciferol, seed eaters who have access to fish oils does not require either sunlight or full spectrum light to have adequate Vitamin D3 levels.

While most full spectrum lighting initially supplies middle range ultraviolet for Vitamin D synthesis, much of this wavelength is lost as the device ages. After 500 hours or so, little measurable UVB remains. Refer to Figure 2 to see how little UVB was initially present in comparison to sunlight. It becomes of more importance from this perspective to ensure that your bird is receiving a quality diet which supplements Vitamin D intake. This may be confirmed by finding either calciferol or cholecalciferol listed in the ingredient list of packaged or pelletized foods. Provision of green vegetables and fish oils will assist in this process. All the lighting in the world will not offset the effect of poor diet. Do not expect any lighting source to uniformly and completely meet your bird's Vitamin D needs.

The importance of full spectrum lies in providing a balanced spectrum and regular photoperiod for your bird. This is not just a couple hours per day, but during a 12 hour period in those times your bird is without natural sunlight. Your bird uses this light to set its internal clock, regulate its endocrine system and metabolism, decide when and how attractively to feather, ward off disease, and remain generally healthy and happy. Proper use of light, ignoring the Vitamin D question is to move beyond myth, and into healthful fact.


An issue of recent concern to many veterinarians and bird owners has been the possibility of flicker produced by flourescent lighting. Flicker is defined as the visible pulsation of a light source. The current controversy involves the fact that many older or cheap fluorescent fixtures have a flicker at about 60 cycles per second. Unless the lamp is malfunctioning or very old, humans cannot perceive common line voltage frequencies. While the ability of tropical birds to perceive line voltage frequencies is well within the capability of the avian eye and brain, several factors should be considered prior to raising an alarm over the use of standard fluorescent fixtures. Keep in mind throughout this reading section that it is the fixture, and not flourescent tubes which contribute to this issue.

It is a recognized fact that all species fare better under the influence of full spectrum lighting solutions. This regard is given to feathering and molting cycles, endocrine and breeding behaviors, and uniform visual fields. It needs further recognized that birds are not aversive to, nor experience negative responses from long term daily exposure to these light sources. Therefore, all available scientific and historical information suggests that any flicker induced by the use of a magnetically ballasted fixture is neither distracting nor harmful to the bird. The scare tactic used in bringing this matter to the attention of the birdkeeping public is that birds are being "kept under a disco strobe light".

The main problem here is that a number of avian veterinarians and parrot lecturers have become swept up in this concept, causing undue concern about potential and imaginary dangers. This is in complete disregard for scientifically established evidence which dispels any doubt that conventional full spectrum solutions are safe and beneficial to the physical, psychological, and endocrine health of birds. Some have advocated switching to incandescent lighting which is improperly marketed as full spectrum. This labeling is patently false, and the use of such devices does pose legitimate threats to the health of birds. More information on this appears in the section "Small Packages-Big Promises".

There are several ways to eliminate flicker from a fluorescent lamp. The first involves the use of a special lamp and fixture which delivers direct current (DC) to the cathode ends of the device. Unfortunately, there exists no DC capable tube in under 8 foot lengths which is full spectrum and meets avian lighting needs. The more common and available means to reduce this flickering issue involves the use of fixtures which employ an electronic ballast.

Unlike the magnetic ballast which is most common in low cost and older fixtures, the electronic ballast converts the line voltage frequency to a much higher rate, generally 20,000-60,000 cycles per second (cps), as opposed to the line frequency of 60 cycles per second. Better quality ballasts operate above 42,000 cps. Figure 1 shows how the chance of flicker decreases with increased frequency. Example A is twice the rate of Example B. If we chose Example B to represent 60 cycle line frequency, an electronic ballast would be 700 times as fast. This means that the light output is continuous, without any possibility of flicker.

Figure 1

An electronic ballast was originally designed to power a special type of fluorescent tube, referred to as a T8 type. These lamps are somewhat smaller in diameter than the conventional T12 class tubes that are used in general lighting. The increased frequency delivered by the electronic ballast make these lamps brighter than their standard counterparts. Improvements to the electronic ballast allow for energy savings, and also the ability to power any fluorescent lamp except for older, preheat types.

Additionally, using an electronic ballast with a conventional tube increases its brightness by approximately 10%. The only downside to using an electronic ballast with a conventional T12 series lamp is that due to the increased frequency delivered to the cathode ends, there is a decrease in the usable life of the lamp. In most circumstances, this is less than a 25% decrease over the entire lifetime of the lamp. Given the standard changeout time of 9000 hours for aviary applications, this only amounts to a 10% reduction in full spectrum lifetime. Result: changeout in 22 months instead of 24 months. The good news is that the best lamps available for avian use are only available in the T8 package.

The answer to this supposed problem is simple. When purchasing new, or upgrading an existing fixture, do not buy a cheap magnetic ballast fixture. Any electrical or lighting supply house can provide you with a reasonably priced ($20-40) electronic ballast fixture. Using these in combination with a high quality T8 lamp such as the Philips TL950, also increases the useful full spectrum life of the lamp to approximately 10,000 hours. The additional cost of these fixtures is more than offset by energy savings, extended lamp life, and better quality lighting solutions for your bird.


Back before Vita Lite introduced the first full spectrum flourescent tube, the preferred method of lighting was by incandescent bulbs. For use with birds, bulbs intended for reptile use were often the lamps of choice. This method had a long and colorful history in the poultry industry. Two problems were noted with chickens, however. It was difficult to prevent cannibalistic behaviors, and the birds were highly susceptible to tumors. We know now that these things were the result of unbalanced incandescent light. Since that time, new kinds of screw-in lamps have appeared, both incandescent and fluorescent.

Many manufacturers used a coating that filtered out a great percentage of the yellow light given off by light bulbs. Made by companies such as ESU (BrightLight), Verilux (Neodymium), Zoo-Med (Daylight Blue), and Ott (bioLIGHTBULB), these devices advertise "full spectrum performance". If they are speaking about the full spectrum of a regular light bulb, then they are telling the truth. Figure 2 shows a comparison of sunlight, a true full spectrum fluorescent, and these so-called "full spectrum" bulbs.

Figure 2

It is obvious that these kinds of lamps are nowhere close to full spectrum light or sunlight. Many companies make this claim, but none measure up. Unfortunately, the Federal Trade Commission does not currently require lamp manufacturers to meet any kind of labeling requirement in their marketing information. This is the real concern general birdkeeping public. Claiming "full spectrum" or "healthful" benefits from these lamps is a clear violation of Sections 5, 12, and 15 of the FTC Act. As such, all interested parties should file a deceptive advertising complaint with the FTC. The electronic form for this is located at . This is the only way to get "truth in advertising".

This is not to say that there are not very clear technical specifications that a lamp must meet prior to being called "full spectrum. Duro-Test, which produced the first full spectrum fluorescents to John Ott's specifications, define 6 absolute technical qualifications for a lamp to be full spectrum. These definitions are also reflected in the American Society for Testing and Materials specification (ASTM E308), the Commission Internationale de l'Eclairage/International Commission on Illumination (CIE 15.2), and the International Standards Organization (ISO 5, Part 3). Incandescent lamps do not even remotely meet any of them.

Compact fluorescent screw-in lamps are another case. Several of these devices are properly full spectrum lamps. But, as Paul Harvey says, now "The Rest of the Story". When brand new, these lamps just barely meet the criteria for full spectrum. As soon as one turns the lamp on, it begins to degrade. The higher spectra decline first. This is the UV and blue end of the lamp. After a couple hundred hours of operation, performance has slipped downward to where the lamp is now a "wide spectrum" lamp. Translation: in a few months, these expensive, high end lamps are no better than a regular compact lamp. And they provide no better positive benefits to your bird. The lesson here is "buyer beware".


Neither this, or any other article can be all inclusive on the issues surrounding avian lighting, environment, and health. It is for us, as stewards of our feathered charges to look in as many directions, and at as many sources of information as is possible to ensure that we are providing the best possible environment and quality of life for our birds. It is this writers hope that you can now look a little further into the realm of lighting environment, and help to bring bird lighting into the 21st Century.

Much more information on lighting can be found at the Birds and Lighting website.

Winged Wisdom Note: Patrick Thrush is a graduate of the University of South Florida, with degrees in Psychology and Sociology. He has been professionally involved with avicultural lighting research since August of 1998, is the author of a number of articles on the subject and is the creator of the Birds and Lighting website. Patrick lives in Central Kentucky with his wife Donna, six cats, and Pedro the Blue Crown Conure.

Copyright © 2000 Patrick Thrush and Winged Wisdom. All rights reserved.

Winged Wisdom Pet Bird Magazine

A pet bird ezine, pet bird e-zine, for pet parrots & exotic birds.
Articles on the care & breeding of pet birds, pet parrots & exotic birds

Birds n Ways Home Winged Wisdom Home Articles Listed by Topic

Cockatoo Parrot picture courtesy of Glasgow Enterprises

Copyright © 2000 Birds n Ways All rights reserved.
Page design: Carol Highfill ---- Last update: January 1, 2000

Contact Us