Introduction to Implementing Lighting
Lighting our chameleon cages is an involved execution as we break sunlight up into three different lamps: light for vision, heat, and UVB. Not only do we need to co-ordinate strengths of these light sources, but we need to place them in a limited physical area above our cage where they jockey for space with mist heads, foggers, fans, and whatever else we need to create an appropriate environment. In this module we will review implementing the three functions of replicating the sun.
The most involved will be UVB.
As mentioned, the common challenge will be not only determining the right strength and shape bulb, but in finding a place to set them for full benefit. Some fixtures come with legs to stand on, some with chain to be suspended, and some with clamps. Once you read this section, you will have an idea of which lights you will get and can then decide on how you will mount them the required distance from the cage top.
In my examples here I will be placing the cage on a wire baker’s rack with adjustable shelves giving me the freedom to place a “lighting shelf” at whichever distance above the cage I select.
To give the chameleons the bright white light they need for vision we want to provide the best full spectrum lighting we can. Presently, 6500K fluorescent tubes have shown to be effective. We are coming from an era of chameleon’s cages being so poorly lit that they looked like caves in our living rooms. I have not had issues with how close I have T5 or T8 white light bulbs to the top of the cage. Both resting them on the top and suspending above the cage has been effective. The latest LED bars that have come out are quite powerful and I appreciate that strength when I am using my rack system to hold the lights a number of inches above the cage top.
You must consider how much space you have above your cage. When I am using my wire rack, I will have a quad T5 bulb fixture with four 6500K white light bulbs, a single bulb fixture for UVB, and a 10” reflector for my basking bulb. But with set-ups that have reduced space, the UVB and daylight can be combined into one dual bulb fixture. Or else you can used one LED bar and one single bulb reflector.
Our heat bulbs produce a gradient where the temperatures immediately off the bulb are too high while the perfect temperature is somewhere in the cone below. The higher the wattage the wider the area that will be at the desired temperature. Your job is to ensure that the bulb is lifted off the cage top far enough that the chameleon is not exposed to dangerous levels of heat. Chameleons are prone to burning themselves under heat lamps that are too hot. While we give temperature numbers for the basking area in the care sheets, the best way to ensure that the temperature is warm, but not too hot, is to use the back of your hand to check that it is safe. It obviously is a subjective test and you will have to make allowances for your personal sensitivity. But your skin can easily detect temperature and if it is comfortable for the back of your hand to stay at chameleon head level for one minute then it is likely that this is a safe level. You can always use a temperature gun for actual numbers.
When we place the basking bulb we want to be extra careful to secure the light fixture as slipping or falling could be a fire danger. Many of the reflectors, including the one I use, come with clamps that can be used to elevate the reflector above the cage. The danger with using the clamp is that it is easy for it to slip or even fall off once it gets older. If you do want to use the clamp lamp then use zip ties to cinch the clamps tight so they cannot slip.
The best way to accomplish a large area of the cone at a desired temperature without the top of the cage being too hot is to have a high wattage bulb placed a distance away.
Implementing UVB: Know our goals. Know the tools
Our goal for including a UVB light is to provide our chameleon the option of basking in enough UVB that their body can produce the necessary Vitamin D3. On the other hand, we are aware that too much UVB can cause health problems (sunburns, eye issues, and decreased fecundity). Thus we want to make sure that the range of UVB in our cage is both effective and safe. Our execution of this requires us to decide on the Minimum Effective UVI as well as the Maximum Safe UVI.
Minimum Effective UVI: The minimum UVI that must be present in the cage for the chameleon to make the required amount of vitamin D3.
Maximum Safe UVI: The highest UVI that can be present in the chameleon cage to not cause health issues.
These numbers are exceedingly difficult to nail down with certainty as needs will change by species and lifestage. But all we need is a magnitude. We are including in the cage ample space to hide and get UVI 0 so our main focus is on determining the Minimum Effective UVI. But we are cognizant of the Maximum Safe Level because, as we will find out when we take UVI readings, the levels coming off of our lamps in the first inches are beyond what is seen on Earth naturally. This is no place for an exposed belly of a chameleon walking upside down on the cage top!
My personal goal is for us as a community is that we are so proficient with our UVB implementation that we do not need dietary vitamin D3. You will note, though, that the advised supplementation routine here does include one or two doses of a supplementation that includes vitamin D3. This is as an insurance against lights that go bad or are not replaced as they should. The general community does not have access to Solarmeters and is unable to regularly check their UVB levels. Thus this inclusion of D3 is not because the UVB is insufficient, it is to help mitigate the realities of the current state of community capabilities. But, for people that have Solarmeters and check their UVB light levels, you are welcomed and encouraged, to switch to a no D3 supplementation routine as I have.
The Minimum Effective UVI
There is much on going work to determine what the minimum effective UVI is for different species of chameleons. The greatest amount of work, so far, has been done by Dr. Gary Ferguson with panther chameleons. The Ferguson zones were named after him and they list the Veiled, Panther, and Jackson’s Chameleons in Ferguson Zone 3 which is UVI 1-2.6 with a maximum of UVI 7.4. (If you are interested in the discussion about Ferguson Zones, a thorough paper by Dr. Francis Baines discusses UVB in the captive environment. https://www.jzar.org/jzar/article/view/150/89)
The Jackson’s Chameleon was listed as Zones 2-3, though feedback from the hobbyist community suggests that the Jackson’s Chameleon belongs in zone 3. Testing will continue, but I would lean towards zone 3 rather than 2. Once again, all these numbers are there for us to use as a step for further testing. They are not meant to be definitive. It is our responsibility to take the hard work done by these scientists and expand and add to the collective knowledge. Remember, they have all reptiles, amphibians, and other animals they work with. We live and breath chameleons. It is OUR responsibility to continue their work and add to what we know about chameleons. Expanding on their work is NOT saying they are wrong. It is being actively involved in the work instead of passively consuming. The more people experimenting the better.
The Ferguson Zones were derived from interpreting the natural data and provide a reasonable starting point for us to take it to the next level. We in the chameleon community need our UVB to provide enough energy that a female can lay a fully calcified clutch of eggs. This is the final confirmation check we use to refine these numbers. It is absolutely true that babies, adults, and gravid females may need different amounts of UVB, but with a proper cage set-up the chameleon will have the option to UVB bask and hide as much as they need.
The calcified egg test was performed for Veiled Chameleons by Pete Hawkins and myself where we confirmed that UVI 3 was sufficient to provide for a calcified clutch. This does not mean that UVI 3 is the Minimum Effective UVI, but it is an effective UVI and we will use UVI 3 as the target UVI in our set ups because of this confirmation.
Jonathan Hill, of iPardalis, shared with me that he has raised up three generations of panther chameleons under UVI 3. He used a variety of bulb/fixture/distance configurations, but tuned them in with a Solarmeter 6.5 to UVI 3 at the basking branches. The results are stunning. This is significant because his only supplementation was using the Arcadia EarthPro-A which has no vitamin D3 (or preformed vitamin A, for that matter). This is an implementation of the multi-generational test well over with four generations of eggs produced where the mothers and their mothers have never had synthetic vitamin D3. Their vitamin D3 came solely from UVB at UVI 3. So this establishes UVI 3 as a valid effective level for panther chameleons. Of course, this does not mean UVI 3 is the Minimum Effective UVI. But we know that UVI 3 is in the Effective Range for both Veileds and Panthers by the passing of the calcified egg test.
I am confident that we have further refinement of this number in the near future as more and more members of the chameleon community test these UVB levels and supplement with vitamin D3 free powders.
This is a third generation male Panther Chameleon that has been raised under UVI 3 and supplemented with only Arcadia EarthPro-A. The significance of this is that there has been no synthetic Vitamin D3 or Vitamin A in this multi-generational colony maintained by Jonathan Hill, of iPardalis.
Fourth generation well calcified panther chameleon eggs produced by three generations of panthers raised under UVI 3 and no supplemental vitamin D3 or vitamin A beyond standard gutload practices. This is from a multi-generational colony maintained by Jonathan Hill, of iPardalis.
The Maximum Safe UVI
In nature, chameleons get one UVB level at a time. They do not get twice the UVB just by crawling up a couple of inches. Our lights, on the other hand have a distinct gradient and we must be smart about it if we are to provide the right levels over the right area without allowing our chameleon to wander into dangerous UVB levels. Since UVB damage is not only in intensity, but also in duration of exposure this is a difficult parameter to determine. Presently, the one controlled study I am aware of is a personal study I performed to compare the effects of Veiled Chameleons raised under UVI 3 and UVI 6. I saw no increased growth with UVI 6 so I determined there was no benefit to giving more than 3. Although this was not meant to determine if 6 was a health level for long term usage I can at least put a stake down and suggest that there appeared to be no issues at UVI 6. Thus, that is as good of a Maximum Safe Level for Veiled Chameleons as we have at this moment. Panther Chameleons are at a lower elevation so I would encourage erring on the lower side for them. Yellow Crested and Machakos Hills Jackson’s Chameleons show similar basking behavior (out in morning and retreat in afternoon) and come from about the same elevation as Veileds so the numbers would, presumably, be able to be used for a start point. We can use the UVI peak values that are listed in the Ferguson zones for now, but this was not necessarily how they are meant to be used. This is just the closest we have to a starting point and, with the information we have now, seem to be reasonable for our usage.
Learning to Effectively Use the UVB Gradient
Gradients are inherent in the UVB lamps we use and we must use them wisely.
Every UVB lamp has a cone-like shape of UVB emitting from it. This cone can be broken up into three sections.
Dangerous UVI: Readings directly off the UVB bulb will be unearthly. For perspective, UVI 13-15 is around the maximum we are recording in the standard chameleon habitat at high noon. Within an inch or two of these artificial UVB lamps you can easily see UVI 40 or even up past 150 where one has to wonder how accurate the meter is! And these are measured through the filter of one layer of screen! To be sure, the UVI level drops dramatically each inch you move away, but, especially with babies that crawl the top panel, we need to be very aware of the levels directly off our lamps. If we do not elevate the lamps then we allow our chameleons to expose themselves to ultra-high levels of radiation. We do not know exactly where the Dangerous UVI starts, but I believe I am reasonable in assigning anything beyond what a chameleon could possibly encounter on Earth into this zone. Until further information becomes available, I will assign anything over UVI 13 into the Dangerous UVI range. This has real world consequences as just about every UVB lamp produces radiation above UVI 13 and T5 bulbs directly on the screen will introduce these levels to your cage. Remember that these lamps were designed to produce enough UVB that it can reach a basking lizard on the floor of the cage. When we set up a system for arboreals where the lizard can crawl up to an inch or two of the bulb we must adjust our implementation. This is a prime example of how important it is to understand the tools we work with.
Excessive UVI: This zone is called Excessive because it is made up of UVB levels that are tolerable and may be encountered in the wild, but are beyond what is necessary to synthesize sufficient vitamin D3. The Excessive UVI zone is bounded on the upper end by the Maximum Safe UVI. We do not know where the Maximum Safe UVI is so we will have to make an assignment of what the maximum UVI is that we will allow in the cage. It makes sense that we would limit the UVI in the cage to something as far away from the Maximum Safe UVI as possible. The lower bound of this zone will be the highest UVI that we will allow in the cage.
Maximum Cage UVI: This is an important UVI level to determine in your husbandry. This is the maximum you will allow your chameleon to expose himself to. Imagine your chameleon hanging from the top of the cage. What is the maximum UVB you want their belly exposed to? The safe level is, like so much else here, unknown at the present time. So we have to make an educated decision. I have tested veiled chameleons in a cage that had exposure to UVI 6 and they appeared healthy. The Ferguson Zones 3 allows for a high level of 7.4. Therefore, with these two data points, it seems reasonable that we use UVI 6 as our maximum cage UVI.
Overhead UVI: This is the airspace between the Effective Zone and the Maximum Cage UVI. This is the area where we do not expect our chameleon to be in. Our goal is for our chameleon to spend its time with its body in the Effective Zone. The only reason this zone is worth specifying is that the gradient nature of our UVB lamps and the 3D movement of our arboreal chameleons requires us to understand all these zones.
Effective Zone: This is the most important zone to turn our attention to and to experiment with. We need to decide what levels we want our chameleon to bask in and then we must find a lamp/reflector configuration that will provide an Effective Zone large enough for our chameleon’s body. We have experiments that show that a UVI of 3 is sufficient for veiled and panther chameleons to produce fully calcified eggs without dietary D3. Therefore, I will place the top of the Effective Zone at UVI 3. This will be the level that I would like the back of my chameleon to bask in. Due to reports from the field of when chameleons bask and corresponding that data with hour by hour UVI data I suspect UVI 1 would be a sufficient lower end to the Effective Zone. The team behind the Ferguson Zones has their zone 3 to go from UVI 1 to 2.6 so this range has other support. We continue to test in the chameleon world and are working to validate these numbers further. But, for now, targeting an effective zone of between 1 and 3 is our goal. By definition, the Minimum Effective UVI is the lower bound of the Effective zone.
Ineffective Zone: Lower than the Minimum Effective UVI the UVB is too weak to sustain vitamin D3 synthesis. We will not be spending much consideration of this zone. Not only does it dissipate to zero without consequence, the foliage in the cage often blocks the light before and takes the UVB to zero simply by physically blocking it.
These numbers are reasonable with what we know now. I look forward to the community testing more and generating more data to refine our understanding of how to implement UVB.
Selecting a UVB Profile
To select the proper UVB solution consider the shape you would like the UVB to take in your cage. By learning the principles here you are able to make an intelligent decision as to which UVB lamp to use. But, by far, the most useful and used form of UVB is the T5 High Output fluorescent bulb. They are available from 2% UVB strength to 14% UVB strength (the percentage of light output in the desired UVB wavelengths). And we further modify the strength by the fixture and the distance above the cage. You can select a UVB lamp with the following steps. Note that if you are confused with all these options and just want to put together your cage there are build guides provided that require no deep understanding of the secrets of the universe! So if you don’t absorb everything here do not worry. You can always build an effective cage set-up with the build guides and come back to soak in the fine details.
- Find the lamps that cover the cage area you wish to have UVB. With the vertically orientated “pillar” shape cages this is generally the width of the cage. So a 24” wide cage would use a 24” wide fixture. You do have an option with the wide format cages to irradiate just the open area. If you recall, the Forest Edge concept applied to a wide format cage has one half of the cage open and one half is dense leaf cover. UVB is needed only in the open area to simulate the chameleon being able to hide in the dense foliage. So, with a 45” wide Dragon Strand Large Atrium a valid design option would be to use only a 36” UVB fixture or even a 24” fixture.
- Review the different configurations of the lamp size that will give you the UVB gradient that provides a UVB Effective Zone which covers both the height and length of your chameleon. The light in the single bulb fixture will be more powerful than in a multi-bulb fixture so there will be multiple options available to you. You can consider how much space you have to dedicate to fixtures. You may have the space to have a quad bulb fixture for daylight and a separate single fixture for UVB or else you may have space only for a dual bulb fixture for both daylight and UVB. Once you understand the interactions between bulbs, reflectors, and distance you are able to create an effective UVB system that matches your cage and UVB needs.
Note that the same bulb can produce different strengths depending on whether it is in a single bulb reflector (maximum output) or multi-bulb fixture where the other bulbs will block the reflection and efficiency.
The UVI numbers below were specifically tested over a Dragon Strand chameleon cage to ensure that the numbers reflect what one would see with the light passing through a screen panel. These numbers are NOT valid if you remove the screen panel as they will jump up.
The chart below revolves around getting UVI 6 at the cage top. So it shows how high the UVB fixture needs to be above the cage so that a UV meeter will read UVI 6 inside the cage under the screen layer. Then the blue effective area shows were the resulting UVI 1 to UVI3 will be. The idea is that you place your basking branch so the body of your chameleon comes up to the top of the effective zone. The levels shown here are for the line directly under the bulb. The levels drop of as you go to either side of the center line.
The absolute best way to set up a UVB system over your chameleon cage is to have a Solarmeter 6.5 UVI meter. That way you can measure your exact lamp strength and create a custom configuration. You will also be able to track the lamp’s slow degradation over the year and adjust when necessary. The problem with making a chart such as the one below is that readings can change dramatically depending on where the meter is sitting or how it is pointing. Each lamp will give a different reading depending on how long it has been on and how long it has been in use. Thus you should expect that these are magnitude numbers only. They are enough to get you started.
UVI 6 at the top of the cage was the reference chosen for the distances on this chart. This chart could have easily been referenced around a basking branch at 6″ down with UVI 3 at 3″ above the basking branch. You can easily extract that from this chart. Simply move the light further up. For example, if I wanted to use a 6% T5 in a single bulb reflector with a basking branch at 6″ I would suspend the light 6″ above the cage instead of 4″. This would put UVI 3 right about where the back of the chameleon would be if they were perching on the basking branch.
The following chart characterizes the Arcadia brand UVB lamps. A chart for Zoo-Med Reptisun bulbs will be coming soon. Until then, a rough equivalence is the 5.0 with the Arcadia 6% and the 10.0 with the Arcadia 12%.
IMPORTANT: UVI measurement is highly imprecise. The level read depends on lamp active age, lamp on-time, brand and shape of reflector, position of the meter, and angle of the meter. The most accurate way to tune in your UVB lamp is with your own Solarmeter 6.5 meter. These charts provided can offer a snapshot of a sample of these bulbs.
Chart 1: Minimum Height of UVB Fixture Above Cage Top To Limit Maximum Cage UVI to 6
This chart shows the height you would have to raise the lamp fixture above the cage top to ensure that the highest UVB level a chameleon can expose itself to is UVI 6.
The Compact Fluorescent Light (CFL)
Compact Fluorescent Lights (CFLs) were developed to bring fluorescent technology to the wide spread screw-in light sockets. CFLs have gotten a bad rap in the chameleon world because of the under powered bulbs included in the ubiquitous Chameleon Kit. But they are a tool like every other lamp and need to be used properly. Even the low powered 13W bulbs have use in baby cages. But we should not do a broad brush across all CFLs because of the 13W 5.0 in the Chameleon Kit. When you jump up to 26W lamps you are getting respectable penetration. In fact, as the chart below shows, most CFLs will require you to prop them up above the cage to ensure you don’t get unnaturally high levels of UVB in the cage. For example, I placed an Exo-Terra 26W 200 on top the cage any chameleon crawling on the screen under it would be blasted by a UVI in excess of 150. I caution the community to be careful of making over reaching statements regarding CFLs. The Reptisun 13W 5.0 CFL is the baby brother of some pretty intense lamps.
The measurements below were taken with a 10.5″ reflector so the resulting UVB area was quite satisfactory for a standard chameleon. Smaller reflectors will focus the UVB beam a bit more.
Case Study: Adult Male Veiled Chameleon in a 24” x 24” x 48” Cage
Say we decide to take what information we have of the experiments we have run in the community, combine them with the Ferguson Zone model and create a scenario where we want the maximum UVI level in the cage to be UVI 6 and we want the basking branch at 6″ below the top of the cage. We want the UVI to be 3 at the back of our chameleon with the rest of the body in a zone between 1 and 3. I am estimating that 3″ above the basking branch is suitable for back height. All of this is an estimate anyways as the chameleon will be making his own decisions. So we are looking for an effective zone of UVI 1 and UVI 3 that is large enough for our adult male veiled chameleon to fit his body in. To this end, I changed the chart a bit to try to get UVI 3 at 3″ down (which is 3″ above the basking branch.
There were a couple of lamps that would not allow me to get UVI 3 at the back of my chameleon without introducing more than UVI 6 in the cage. If I used these I would end up with a little less than UVI 3 on the back of my chameleon. What we can gather from this chart is that if I had any of these bulbs and fixtures that I could get a suitable Effective Zone across the body of my adult Veiled Chameleon. So if I already have any of these bulbs, this chart tells me how to set them up. If I am using this chart to help me purchase a bulb and fixture then I want to select the profile that gives me the cleanest implementation.
The following configurations will give us the UVB profile we desire. You can select the one that best matches your desired cage set-up.
UVB Fixture Resting on Top of Cage. If you are resting your UVB fixture directly on the cage top the only linear tube option that will give you no more than UVI 6 into the cage is the Arcadia 6% T8 bulb (or ZooMed T8 5.0) in a single bulb fixture. Though T8s are an older technology, this well tested bulb will give you a workable 5″ effective zone. If you already have the bulbs then you can use the T8 6% or 5.0 in a single bulb reflector resting on the top of the cage and fulfill the parameters of UVI 6 or less at the top and a basking branch 6″ below in the Effective Zone.
Single Bulb Fixture. If you have space for both the daylight and a UVB light then a single bulb reflector is my choice for implementation. It has the greatest flexibility and I can dynamically adjust height over the bulbs lifetime using my UVB meter. Either a T5 6% or a T5 12% is possible. But you will need to suspend them above the cage to ensure UVI 6 at the cage top. The 12% and its big brother the 14% have long Effective zones. I usually choose the T5 HO 6% in a single bulb reflector mounted 6″ above my cages as my standard approach.
Multi-bulb fixture. Often, because of cage top space, you may want to combine both the daylight and UVB into one fixture. In this case, a 6% UVB in a dual fixture needs to be suspended only 2″ to provide a proper profile. Many fixtures developed for the marine community come with feet of their own which rest on the cage side and can raise the lamp up a couple inches. A T5 6% (or 5.0) in a dual or quad bulb fixture raised up a couple inches above the cage is probably the easiest approach.
Compact Fluorescent Lights. As the CFL chart above shows, there are a number of CFLs that would provide the desired UVB profile. In a 2′ x 2′ x 4′ cage, a 10.5″ reflector will create a very satisfactory UVB basking area using a CFL. If I were to pick one to use, the Reptisun 26W 10.0 is a top candidate. One serious caution when considering a CFL for your system is the very steep gradient. Folding the tube on itself to create the CFL shapes removes output efficiency. Because bulbs are facing each other they block/absorb each other’s light. So to get the same amount of UVB out they have to produce more UVB. This process results in UVB levels in the first couple inches of the bulb at UVI 60 all the way up to UVI 180 (and this is measuring through screen). I avoid CFLs because the gradients are packed so tightly (meaning the change over each inch is enormous).
The chart below was developed to illustrate the linear T8 and T5 tube choices for this scenario.
Resting the UVB fixture on the top of the cage
One important thing to note is that, when using a reflector, the only configuration that gives us the UVB profile we want with the UVB lamp resting directly on the screen top is a Arcadia 6% T8 or ZooMed T8 5.0 and a basking branch 6″ or 7″ below the top screen. Every other bulb configuration requires the UVB bulb to be suspended above the cage. Direct resting with T5 lighting is the industry standard and, obviously, we do not have piles of dead chameleon bodies, but it is important that we understand what risks we are incurring by doing this. The biggest danger in this is, obviously, the high UVI at the cage top. With an adult chameleon happy in their cage this is less of an issue as they will not spend much time, if at all, hanging from the cage top. This becomes an issue with younger chameleons that tend to be all over the place. It is pretty much accepted that chameleons can detect UVB and “UVB bask”, but it is not yet known if they are able to regulate it safely. If their ability to regulate heat safely is any indication (they easy burn themselves and continue to bask), we should not assume they have any ability to avoid UVI 42 on their belly. The health effects of this kind of exposure on a chameleon has yet to be determined, but it would be fool hardy to assume there is no effect until proven otherwise.
Why is this so complicated?!?!
The reason why it is so important to understand how our implementation of UVB works is that new technologies and new information is constantly becoming available. By understanding the underlying principles we can understand how to change what we are doing to take advantage of advancements. Are Compact Fluorescents Lights or Mercury Vapor bulb effective or not? By understanding the profiles and gradients you can make an intelligent choice as to whether it is appropriate for your situation.
This module is part of a class on Setting Up Your Chameleon’s Cage where you learn how to build up a complete chameleon environment from start to finish. From this point you can either go back to the home room and see the other modules in this class or go on to the next module where we dive into how to use plants in the chameleon cage!