Some thought on lighting.

Had an excellent chat today, thanks guys. It helped me to understand some things I have been going back and forth about.



I made a reference that I wanted to record so I could remember the importance of the topic and possibly help out other new keepers residing in AZ.

All of these thoughts are based on the information presented @ http://www.uvguide.co.uk



What i was talking was concerning a few things.



What levels of light do chameleons need.

How much of these levels are present in Arizona. ( Believe me your skin tingles outside in the summer, its a very strange feeling.)

Can this pose a danger when I take my chameleon outside for natural sun light.

You can see the average output of the commonly used reptile bulbs here. Graph #1 shows that at 2 inches the output is around 200 uV / cm2 ( microwatts per centimeter squared ). I really hope nobody is putting there lights that close.

At the more likely 6-12 inches we see 80 uW / cm2 and 40 uW /cm2 respectively. Keep in mind these were 24 inch bulbs, but the shorter bulbs should share similar qualities.

Regarding chameleon light levels.

Rainforest species such as some types of chameleon naturally avoid any such high exposure. They need UVB, but at much lower levels. Fig. 8. This Globifer's Chameleon seeks out dappled shade Their more sensitive skins manufacture all the vitamin D3 which they need from brief periods of basking early and late in the day, and the diffused and reflected ultraviolet light permeating the rainforest shade. All species of chameleon have different requirements, but authors vary, too, in their recommendations. The one scientific study we are aware of addresses egg hatchability in Panther Chameleons (Furcifer pardalis) and the authors suggest that a low level of UVB (a gradient between 15-33uW/cm² as measured with a Solarmeter 6.2) supplied for 12 hours a day is optimal. High levels are seen to be harmful.14,19 Our experiences are similar to these findings; one of the current authors maintains gradients of up to 30uW/cm² in all his chameleon vivaria.

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This would suggest that we should use the 12 inch range, but most have been telling me they use around 6 inches. I see no reason to mess with that. The animal likely knows what it needs and its up to us to properly observe and know that an animal moving closer to a UV light is an animal that probably needs more UV.



Natural levels of UV radiation in nature.

While Arizona is not directly shown. She later makes a reference.

Some reptiles are described as "sun-worshippers" including uromastyx, bearded dragons, chuckwallas, and many species of tortoise. In the wild, these spend many hours a day exposed to hot sunshine and high UVB levels, in places Fig. 5. Lazy...or synthesising vitamin D? such as the Mediterranean, Arizona and the Australian outback where peak readings of 350 - 450uW/cm² are commonplace for two or three hours a day, around noon, in the summertime.

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Wowzers! at least its not all year and only around noon time! This is 10 times the light levels of our average bulb at twelve inches.

UV in the vivarium clearly shows that it is possible to cause harm to your reptiles with UV light.

Just two examples from that section

It is believed that reptile skin, being generally much thicker and often more heavily pigmented than mammalian skin, may be more resistant to the detrimental effects of UV light. However, cases of possible "sunburn" have been described; some of these may actually be thermal burns from hot UVB-emitting lamps.33

Excessive exposure to UV lamps is also reported as causing a toxic syndrome and hyperkeratosis (a pathological skin thickening) in side-blotched lizards (Uta stansburiana), lethargy, skin darkening, anorexia and death in iguanas, and egg hatching failure and skin tumours in panther chameleons.

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Tumors!! Not on my watch!

My own personal conclusion is that if I do take my chameleon outside, especially in the summer it should not be for extended periods or in direct unfiltered sunlight. I should be diligent about observing my friends during those times. Seems obvious in retrospect but whatever I enjoyed all the reading.

I hope this was entertaining, useful or otherwise worth the time it took to read.

Any of the material referenced from www.uvguide.co.uk was used with permission. All images and data are property of their respective owner.