FULL SPECTRUM LIGHTING FOR BIRDS
How Natural Light Works
Before we talk about artificial lighting and its affect on birds let’s briefly review the science of light.
The world around us is filled with electromagnetic waves (EM waves). In fact, there are hundreds, sometimes thousands, of EM waves moving through the room you’re in right now. Some of these waves are passing through you, while others are bouncing off of you.
The most important thing to know about EM waves is that
as their wavelength changes, their effect on living organisms also changes.
For example, you can see in the image below that the longest waves are radio waves and quite harmless. As the wavelengths get shorter, they become harmful radiation.
A Look at EM Waves Produced by the Sun (Sunlight)
Most EM waves are man-made; however, this article is about how artificial light compares to sunlight, so we will discuss EM waves that the sun produces. These EM waves have a wavelength between 100 and 1,200 nanometers.
The longest wavelengths that the sun produces are Infrared waves, otherwise referred to as heat.
The shortest wavelengths are UVC, which are 100% filtered out by the Earth’s atmosphere.
Ultraviolet waves between 280 and 400 nanometers are further broken down into categories A and B because the effects they have on living organisms are very different.
Wavelengths in the visible spectrum affect the color that we see
Within the visible spectrum, each wavelength is a different color. Light works by bouncing off of objects and into our eyes. When a light that contains wavelengths in the red spectrum bounces off of a red shirt, our eyes see red. If the light does not contain red wavelengths the shirtappears as a different color to our eye. That color depends on the wavelengths present in the light.
Therefore, a light with more wavelengths present is likely to make an object look more natural.
Mixing and Measuring Final Light
There are a limited number of colors in the visible light spectrum, but when they’re mixed, they produce different colors—much like mixing paint. Scientists estimate that the human eye can see over a million colors, which can be made by mixing various wavelengths of color. If a light were to contain an equal amount of every wavelength, the result would be white light. However, light rarely contains every wavelength, and it’s the mix of wavelengths present that determine the final color. Final color is measured by the Kelvin Scale (K).
When you purchase a light in the store, somewhere on the package will be the light color followed by the temperature in K. A regular household light, for example, is typically a yellowish light at about 3500K. The reason why light is measured in Kelvin rather than nanometers is because it represents the final color, not the individual wavelengths it contains.
The important thing to remember is that the K rating of a light is its final color and does not represent which wavelengths are present in the light to make the final color.
Optical Spectroscopes and Spectrographs
The color of light can be measured by an instrument called an optical spectroscope, which produces a report, called a spectrograph, as shown below. Sometimes a light will have a spectrograph on its packaging.
The written parameters of the report can be confusing, but if you look close you can see that this light is around 6,500K with a CRI of 94.
For the purpose of this article, the graph on the left contains more valuable information. It is a quick glimpse of which wavelengths (colors) are present in the light and at what intensity they are. As we learned above, in the graphic with the red shirt and blue shorts, the more wavelengths that are present, the more natural objects will appear to our eye.
For a fun reference, here is a spectrograph of the sun at noon on a cloudless day. The difference is pretty clear.
A bird’s eye can see more than a human’s
Birds have tetrachromatic vision, which means they can see the visible light spectrum plus the UVA spectrum. Bird experts believe this helps them with identifying food, species recognition, and mate selection. However, there’s no scientific proof that UVA has any effect on a bird’s health.
The other electromagnetic waves that have a direct impact on living organisms are in the UV spectrum
Scientists have subdivided the UV spectrum into many ranges but we will only be discussing the two that are relevant to bird lighting: UVA and UVB. Suntan and the creation of vitamin D are good examples of their impact.
UV wavelengths are invisible to the human eye and act differently than visible light. While they bounce off most objects, they sometimes penetrate them instead. For example, both UVA and UVB rays penetrate human skin. However, UVA rays penetrate deeper, all the way down to the hypodermis, while UVB rays only penetrate to the epidermis.
When UVA rays penetrate the skin, they produce melanin which causes skin to tan and wrinkle. UVB synthesizers produce vitamin D3 and, when absorbed in excess, can cause sunburn along with degenerative changes in cells, fibrous tissue, and blood vessels of the skin.
90–95% of UV radiation that reaches the Earth is UVA. It’s important to note that UVA is present equally throughout the daylight hours and seasons. It can also penetrate clouds and glass.
UVB makes up only 5–10% of solar radiation. It’s strongest between 10 a.m. and 4 p.m. and doesn’t significantly penetrate glass. Additionally, its intensity differs depending on how close to the equator you are.
It is important to note that UVB significantly affects birds’ eyes and many parrot owners have inadvertently caused their pet to have cataracts or blindness by misusing lights with UVB. In a study published by the Royal Society of Biological Sciences, a team of scientists studied a number of species of parrots that are commonly kept as pets and found that they possess UV-sensitive visual pigments (UVS). Consequently, their eyes are highly sensitive to UVB and overexposure can cause cataracts, macular degeneration, and blindness.
SUMMARY OF IMPORTANT FACTS ABOUT HOW NATURAL LIGHT WORKS
- Different wavelengths in the visible spectrum cause us to see different colors.
- The more wavelengths present in a light, the more natural an object looks.
- The measurement of a light’s color (K) is the final result of themix of the wavelength colors present in the light just like the final color of paint is a mixture of different colors.
- Wavelengths in the visible spectrum have no effect on the health of birds.
- Birds are not plants, their feathers do not act like leaves, therefore, natural light does notaffect bird plumage other than how it appears to the human eye.
- Birds can see UVA waves as well as the visible spectrum.
- UVA and UVB do not penetrate feathers.
- UVA has no known physical benefit to birds.
- UVB synthesizers, when absorbed by the skin, produce vitamin D3.
- 90–95% of UV radiation that reaches the Earth is UVA, which
- is present equally throughout the daylight hours and seasons and can penetrate clouds and glass.
- UVB makes up only 5–10% of solar radiation. It’s strongest between 10 a.m. and 4 p.m.and doesn’t significantly penetrate glass. Additionally, its intensity differs depending on how close to the equator you are.
- A number of bird species kept as pets possess UV-sensitive visual pigments (UVS). Consequently, their eyes are highly sensitive to UVB and overexposure can cause cataracts, macular degeneration, and blindness.
The truth about artificial light and how it compares to natural light
In the vast abyss of information on bird lighting, the word “full spectrum” is constantly thrown around by light manufacturers trying to convince consumers to purchase their bulbs. It’s become etched into every bird lover’s brain that non-full spectrum lights are bad for a bird and that if you don’t purchase a full spectrum light bulb, you’re putting your bird’s health at risk.
The truth is that the phrase full spectrum means absolutely nothing. It’s a marketing term that has no scientific or official definition, can’t be measured, and, therefore, can be used to describe any light bulb.
How Full Spectrum Light Bulbs Compare to Natural Sunlight
In reality, there’s no such thing as a light bulb that can simulate natural sunlight; it’s simply beyond the laws of physics. The graph below is a spectrograph of the light produced by the sun at noon on a cloudless day. There’s an incredible amount of EM waves present in high intensities. When the term “full spectrum” was first coined, it loosely referred to the light represented by this spectrograph.
For decades, independent testing labs have measured so-called full spectrum bulbs and found little to no difference between their output and that of ordinary bulbs. Most bulbs marketed for birds that claim to be full spectrum with both UVA and UVB (and are generally two to three times more expensive) are actually selling the same bulb you can purchase at Walmart for $2. The graphs below are two samples that compare “full spectrum” light bulbs to sunlight.
As you can see, neither comes close to the brilliant spectrum produced by the sun. While lighting has evolved since the above studies were conducted, current bulbs are still nowhere comparable to natural sunlight; at best, they’re stretching the truth. Yet, the myth of full spectrum lighting is still passed around as if it’s backed by science.
A plethora of light manufacturers sell standard bulbs, claiming that they have something special that your birds need. The following video demonstrates and records the results of testing several light bulbs that falsely push the full spectrum claim.
Other Issues with Full Spectrum Lighting
Light manufacturers claim that birds need a light that simulates the sun at 5,600K to be healthy. However, that strength only represents the sun at noon on a sunny day. In actuality, the strength of the sun and UV radiation fluctuates throughout the day, ranging from 1,000K to 30,000K. A light bulb, on the other hand, sits above your bird at a constant temperature for as long as it’s on. The notion that an artificial light can truly replicate the sun is unreasonable and unscientific.
Full spectrum light bulbs that do contain UV are often repackaged bulbs for reptiles. Birds are not reptiles and don’t gain the same benefits from intense lighting. Imagine if your bird sat on a flat rock in the middle of the desert all day long. It’s safe to say, it would most likely not fair too well. Never buy a bulb with UVB for your bird, as they can cause cataracts and blindness.
Additionally, the amount of UV that actually reaches the Earth’s surface changes based on many factors, such as time of day, cloud cover, time of the year, and location (the closer you are to the equator, the more UV there is). Each bird species has a different natural environment and, therefore, diverse needs. For example, some of the smaller Amazon parrots that live under the canopy don’t receive any UVB at all while grassland finches are in the sun all day.
Facts About Full Spectrum Lighting
- Full spectrum is not a scientific name;rather it’s a clever marketing phrase that implies a lamp emits natural light.
- Because full spectrum is not a scientific term there is no measurement or definition for it.
- Lamps marketed as full spectrum are usually in the 5000K-6000K color range but in truth do not use the full visible spectrum.
- Sunlight is only 5500K at noon, its color temperature varies from 1700K-27000K during the course of a day. Now thatis full spectrum.
- Very few Full Spectrum lamps include UV waves,and the ones that do are usually made for and marketed to reptile keepers because there is scientific evidence that reptiles benefit from UV lighting. Lights for birds that contain UV are usually repackaged reptile bulbs.
- If there are any health benefits caused by the color temperatureof lighting in the bird room, they are immeasurable and have never been proven scientifically.
- A bird is not a plant and its feathers are not leaves;they will not respond to sunlight like a plant does. Yet, so-called experts constantly give the same advice to bird owners that one would give to plant owners.
- Last but not least, and maybe the most importantly, the goal of lamp manufacturers and sellers, including bird supply stores, is to extract your money with cleverly worded ads and outlandish claims.
What are the benefits of artificial lighting for birds
While the existence of full spectrum lighting is nothing more than a fabrication, there are real benefits to regular artificial lighting. For one, birds genuinely love light and have been known to gravitate toward spending time in areas with light, even if the light is artificial and doesn’t contain UV.
I hear stories from customers on the weekly basis about how their parrot will go back to its cage during the day to sit under the light and how finches and canaries sing more and screamers don’t scream as much.
Setting and Controlling Photoperiod
The major benefit of artificial lighting is that you can control how many hours of light your bird receives in a day, known as photoperiod. Many of a bird’s hormones are triggered by photoperiod, which in turn prompt certain behaviors such as nest-building and migration. Dr. Fern Van Sant, owner and primary veterinarian at the For the Birds clinic, explains the importance of photoperiod:
“If there is one single positive change that pet bird owners can make, it is returning the bird to a regularly recurring photoperiod. Whether in the wild or captivity, most birds demonstrate a remarkable periodicity to their days. Restoration of a regular recurring day and night cycle usually results in a happier and healthier companion bird. Birds have in their brains a finely tuned, light sensitive pineal gland. This gland is likely the mechanism by which birds set their circadian rhythm.”
Each bird species is different and benefits from particular photoperiods. A safe starting point is 10 hours on; however, the best course of action is to conduct online research or ask your avian vet about the best photoperiod for your bird.
Providing proper light
Unfortunately, a bird cage is hard to light. If your bird’s only source of light is from a window across the room or an overhead light, then cage bars, play tops, and toys often block a lot of it. In the pictures below, the customer has a double French door only inches to the left of the cage but without artificial lighting, the cage remains dim. You can clearly see the difference that a cage mounted light makes.
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