How UVB is affected by the surroundings



Place the cursor over the image to see the UVB measurements

A solarmeter 6.2 was used to measure the UVB readings in the UK on an overcast summer day.

The measurements taken should NOT in any way be classed as levels of UVB available in the wild or indeed acceptable levels of UVB for captive Chameleons . The point of the above is purely to show the volume of UVB available is effected by the surroundings.

Summary of Results

54um - this was the highest reading obtained and was taken in the open and above the trees.

30um - the reading on the top of the small tree in the foreground was noticably lower then the highest reading obtainable. It can be assumed because the reading was taken on the top of the tree some UVB was absorbed by the leaves and therefore this drop was caused by the reduction in reflected UVB as apposed to reduction in direct UVB.

18um - this reading was taken at the edge of the gap in the tree. A site the Panther Chameleons which are allowed to sun themselves in the garden (supervised obviously) seem to prefer. This area provides dappled light and suitable branches for perching. Only a third of UVB reaches this area.

10um - in the shade under the tree in the foreground little UVB penetrates.

22um - this is another area favoured by the chameleons but mainly on a hot day. The site where the measurement was taken was right at the front of the bush on a branch previously used by Panthers.
Even though this spot receives direct sunlight the surrounding leaves absorb significant levels of UVB.

13um - this area was expected to produce good levels of UVB because of the reflective properties of rock and gravel. In testing however this area produced the second lowest reading. The surrounding foliage clearly absorbs significant levels of UVB before it even reaches this area.

Intrestingly in a small area to the side of the house which is surrounded by light concrete walls with a light stone patio area the levels of UVB recorded there were in excess of 130um. Clearly reflected light can significantly increase UVB exposure.

Suggested Conclusions

Significant levels of UVB are absorbed by live plants

In testing live plants absorbed more UVB than artificial plants

Plant colour (light or dark green) did not seem to make much difference to the levels of UVB absorbed

When setting up a basking spot/area of UV exposure in a captive situation, excess artificial and real plants should be avoided

If a chameleon is too nervous to bask in the open and therefore requires a more heavily planted enclosure (often needed in wild caught individuals) consideration should be given to increase the amount of UV light produced. Doubling up on UV tubes would seem appropriate as a miniumum measure.


Colour and material of surroundings make a huge difference to the levels of UVB. White plastic vivariums gave much more UVB exposure than for example dark wood vivariums. We are currently testing levels of UVB produced from common reptile lights, the UVB at various distances from the bulb and the effects vivarium materials have on the resultant UVB. Click HERE for our latest findings.


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