SHEDDING SOME LIGHT ON THE SUBJECT?
Bird breeders and fanciers around the world have long believed in the benefits of natural sunlight and fresh air for our avian companions. In countries such as Australia, captive birds are almost always housed outdoors. Here in North America, many of us are not blessed with a climate that permits this. Still, given a little knowledge and ingenuity, we can achieve not only the visual appeal but many of the healthful advantages that come with natural or special lighting. Remember that we humans are always grumbling about office light or long dark winters -imagine, then, the justified complaints of creatures whose natural habitat isn't a lobby, a mall, or a living room!Louise Bauck BSc, DVM, MVSc.
LET THE SUN IN
In theory, modern medicine has made it possible to compensate for a lack of direct sunlight by feeding the bird an artificially produced chemically active form - much like our own vitamin supplements - but this approach is not without problems. One of the key issues is correct dosage. Unfortunately, owners who are careless with prescribed doses may be endangering their pet's well-being, as Vitamin D3 may be toxic when given in excess. Frustratingly, we do not know the minimum and maximum safe level of supplements for most pet bird species. We do know that certain parrots such as the macaws seem to be particularly sensitive to Vitamin D3 overdose. In fact, when breeding macaws are housed outdoors, and given high levels of Vitamin D3 supplement in their food - at a level that might be safe for indoor housed macaws - it may be possible in those circumstances for an overdose to occur. Typical problems include renal failure, widespread tissue calcification, and breeding difficulties.
The issue of Vitamin D supplements, then, demands a little thought. But in most cases you will not be able to omit supplements altogether, because without access to activated Vitamin D the 'indoors' bird cannot absorb calcium normally from its food, and the results are catastrophic. Young birds in particular may develop bent and malformed beaks, and bowed and softened leg bones, together with malformations of the ribs and spinal column. The best course of action is to use adequate, not excess, Vitamin D3 supplementation, and to provide access to natural unfiltered sunlight or full spectrum light wherever possible. We do know that full spectrum fluorescent lighting does result in adequate vitamin D activation in chickens, and almost certainly in other bird species (see "Suggested Reading"). Consult your avian health care specialist for correct use of Vitamin D supplements, especially when used in conjunction with pelleted diets, special lighting, or with outdoor housing.
CATCHING RAYS - THE ARTIFICIAL WAY
How is this done? Fluorescent lights are made up of glass tubes containing inert gases such as argon, and coated with chemical 'phosphors' which emit light at various wavelengths when an electrical current causes electrons to strike them. These phosphors give the fluorescent light its special properties.
Although most full spectrum lights are targeted for the reptile market, in fact some can be valuable for birds and also primates. However, correct use of full spectrum lighting involves a little homework. There is no information available on exactly how much ultraviolet light is needed (or is safe) for indoor birds. Remember also that percentages of UVB listed on tube packaging are not usually much help unless you know the total output of the bulb. Your pet retailer should be able to put you in touch with a manufacturer's web site or customer service department if you have questions about the value of a particular bulb for avian species. Fluorescent lights are easy to set up and to use, but follow the manufacturer's guidelines for replacement times. Most emit useful amounts of UVB for at least one year. These lights should be replaced before we are able to see them flicker. Birds can actually see this "flickering" effect in an old tube long before we can!
A BRIGHT IDEA FOR BREEDERS
At one large indoor parrot production facility in Canada, a combination of high pressure sodium light and full spectrum fluorescent light is used to enhance egg production. After January 1, the day length is slowly and artificially increased using both types of light on a special timer. An artificial dawn and dusk is simulated by turning the powerful sodium lights on later, and off first. This seasonal effect is augmented by using other strategies such as 'flocking' (housing the birds in small groups), and artificial rain showers (to mimic a rainy season). On a reverse scale - and of great medical interest to veterinarians and pet owners - is the use of timers to REDUCE simulated day length on birds producing an excess amount of eggs. This is quite a common problem in the unpaired cockatiel and lovebird. Unchecked, this situation can be quite dangerous for the hen, and may eventually require 'spaying' or some other solution. But by blocking the hen's view of outdoor day lengths (windows), and by decreasing each artificially lighted day length by half an hour, ovulation can sometimes be halted without drugs or surgery in 7 to 10 days. However, this phenomenon probably works better in ?non-tropical? birds, as equatorial species (some Amazons for example) probably do not experience great changes in day length in the wild.
High pressure sodium light is a very bright and efficient white light source (it is similar to a "discharge" light like a fluorescent), but is not generally popular with bird producers because individual units are too bright for small facilities, and because of the long warm up period. Regular incandescent bulbs are not always popular with commercial poultry producers, because so much energy is wasted as heat. "Halogen" lamps, low pressure sodium vapor and mercury vapor lamps are cost efficient, but not usually recommended for bird producers because of poor color rendering or spectral output characteristics. Fluorescent light is ideal for most bird owners, and (in the case of the chicken!) a 1992 study in Canada showed that hens have a preference for fluorescent lighting.
LIGHTS, CAMERA, ACTION
Full spectrum light is ideal for visual effects as well as health benefits. You can arrange full spectrum lighting for your cage exactly as you might for a fish tank. An overhead strip light can either be mounted on the cage or ceiling, and should be placed on a timer for convenience. Make sure your strip fixture does not require a 'manual' start each time, or you will not be able to use a timer. Again, make sure that restless parrot-type beaks cannot reach any electrical cords. Viewing your birds will also be enhanced by dark-colored or low reflection bars, particularly when a frontal lighting source is used. Most commercial display aviaries and zoological gardens paint wire or bars black for this reason. Make sure that a zinc and lead-free, non-toxic paint or other finish is used.
Finally, a note on possibly the most important reason for you to re-assess the ways you illuminate your bird and its environment. Small changes in your birds appearance or behavior, cage damage, a dirty cage, and many other problems are easily missed in a dimly lit environment. Some changes are very subtle; an oddly colored dropping, a leg that does not grip the perch well, or an out-of-position wing are all conditions that need a little 'enlightenment' to pick up!
Return to list of Information Sheets
Return to H.A.R.I. Home Page