Reptile & Amphibian Forums

A great discussion began last night about a study that was done on a female pardalis experiencing reproductive issues when subjected to high intensity UV light.

I decided to look into this study, and start asking questions. I thought if a female pardalis could experience reproductive issues, these lights may have long term effects on every chameleon we keep.

It is obvious that too much exposure to most anything is harmful.

It is very early in my study, but here is what I have found so far. The bulb that I have been using (Capture the sun - big apple herp 100w) has high intensity UV. (107 MicroWatts/CM2 of UVB and 400 MicroWatts/CM2 of UVA)

The intensity of the UV starts to lessen after 60cm's (2 foot)

In theory, if you have a 3ft tall cage, the top 2 ft would have the full intensity UV, while the bottom half would have a little less. Through dense foliage, the light would lessen even more. Could your cham get too much UV exposure if the cage is underplanted or too close to the cham. Since the cham spends its time in the top portion of the cage where the UV exposure is at its highest.

The study continues, but I would like to gather opinions on this.

Well, from the little you've mentioned, it seems there are a few holes in the study. First off it's being done on one female cham, nothing can be proven with this, you need a much larger group of animals. Each animal is different within it's own species, so how do you not know she has the genetic predisposition to have pregnancy problems. Also what conditions is she kept in? Variables like food intake, temperature, supplements and many others have to be accounted for because they can all cause similar effects. One more thing is that the intensity of uvb from a mercury vapor bulb is not as intense as what the sun produces outside everyday.
I don't mean to play the devil's advocate, it's just important to be aware that the amount of weight you put on a study depends heavily on how it is conducted. Just as many people if not more have said they have witnessed dramatic benefits to their chameleon since they have used a MVB light, so what makes the study you speak of any different. It's not as easy as, ie: I turn on the MVB light and my cham has begun to have reproductive problems. Many more variables need to be accounted for...and one chameleon is not going to cut it in any scientific arena.
-Daniel

I had similar questions - That was the main purpose for diving into this one.

The report was authored by Gary Ferguson. http://www.bio.tcu.edu/ferguson.html

And I have yet to find details about how the experiment was conducted. Chris Anderson simply told me about the results of the study.

I feel that you may have misinterprted my initial post.

I am looking into someone else's research. I am interested and asking questions.

Joe

>>I had similar questions - That was the main purpose for diving into this one.
>>
>>The report was authored by Gary Ferguson. http://www.bio.tcu.edu/ferguson.html
>>
>>And I have yet to find details about how the experiment was conducted. Chris Anderson simply told me about the results of the study.
>>
>>I feel that you may have misinterprted my initial post.
>>
>>I am looking into someone else's research. I am interested and asking questions.
>>
>>Joe

This information is according to:
Ferguson, G.W., Gehrmann, W.H., Chen, T.C., Dierenfeld, E.S. and Holick, M.F. 2002. Effects of Artificial Ultraviolet Light Exposure on Reproductive Success of the Female Panther Chameleon (Furcifer pardalis) in Captivity. Zoo Biology 21:525-537.
Between 1996 and 1998, 28 female F. pardalis were raised to maturity on low vitamin D diets in nine different artificial UVB light treatments. They were then bred and the successes were compared. The treatments varried from 1.7-55 MicroWatts/cm2 UVB and 9-65 MicroWatts/cm2 UVA. Of the nine treatments, the females of the 7 with the lowest UVB exposure (1.7-18 MicroWatts/cm2 UVB) were exposed for 2 hours and the two higher UVB exposures (49-55 MicroWatts/cm2) were exposed for .5-1 hour at a time. Of the former 7 treatments, those receiving the lowest (less than 5MicroWatts/cm2) and highest (more than 15 MicroWatts/cm2) UVB exposure suffered a hatching success 8.7% lower than those females in mid-levels of UVB exposure (5-15 MicroWatts/cm2). Those females on the two other treatments with short but high exposure treatments did have higher overall hatch rates however they state that "While short exposure to high UVB-emitting sunlamps also promotes successful reproduction, extended use shortens the reproductive longevity of the adult chameleon, can promote skin tumors and shorten the life span of the chameleon (personal observation), and is potentially dangerous to the keeper." They conclude that for females raised on a low vitamin D diet, moderate amounts of UVB exposure is required for successful reproduction. They also note that large cages contain a highly variable light gradient allowing the individual animal to adjust its exposure level, whether it be voluntarily toward its own benefit or not.

That is just a basic run through. Its an excellent article and I think breeders should get a copy to read through it and have on hand. I think a major factor with the MV bulbs having such high exposure levels is the distance from the animal in the cage and the size of the cage and the light gradients in it.
Chris
-----
Chris Anderson
parsonii_hoehnelii@hotmail.com
Chameleon Care and Information Center (CCIC) - http://www.geocities.com/ccicenter/
Chameleons Online E-zine - http://www.chameleonnews.com/

Is it me, or were they merely "exposed" to UVB lights, as if it were a "treatment", and not an extended, daylight period? I have never seen a veild reproduce sucessufuly without either sunlight or calcium/d3 supplementation, even with 12 hour a day, double reptisuns on the cage. I would tink that even at 55 microwatts per cm sq., two hours would hardly be enough.

I thinkalso, while MV bulbs are the best way to go, they shuld not be placed closer than a foot. hold your hand there for a few seconds, it starts to burn, while they don't put out at much UVB as sunlight, they put out a lot of heat, and the combination I think is what causes burns...My veild didn;t like his MV bulb when it was really close, I had to move it over a footaway, otherwise, he would avoid it like it was a death ray. While it's only putting out a half of what it would a little closer, he gewts far more UVB, as he spends more time under it...

Also, a study I read stated that UVB tends to reflect off foliage better than visible light, so even animals in the dappled shade of the forest get significant amounts of UVB, over 20 microwatts per Cm. sq. I beleive...

The 100w "capture the sun" bulbs were actually cooler than I thought they would be. At about 18" from the bulb, I measured 86 deg F.

Compared to a common floodlight that was doing about 98 deg F at a little over 2' away.

What brand do you use?

Joe