Frances Baines in Galapagos Island. Photo taken by Janette Beveridge.
Courtesy of Frances Baines.
Mrs. Frances Baines, M.A., Vet.M.B., M.R.C.V.S.
is a veterinarian particularly well known for her astounding dedication in the research field of visible and UV light for reptiles. she works as an advisor to the Reptile and Amphibian Working Group of the British and Irish Association of Zoos and Aquariums. You can visit her website for more detailed information about her works and research at: http://www.uvguide.co.uk/
A bit of my thoughts:
I contacted Mrs. Frances Baines for an interview request in June 2009. To my surprise, I found out that she was well aware of my blog from her acquaintances. A simple interview turned out to be a very informative and enjoyable experience. I thought of editing some of the info to fit this interview in one section. Yet, I changed my mind. I wanted to share as much as information that I got during the interview to all of you. So, this interview will span to 4 sections instead.
I hope you guys will enjoy this.
My questions are in red.
Mrs. Baines' answers are in blue.
Interview Date: July 7, 2009.
1. How did your interest in reptiles begin?
I grew up in Hampshire, England, near one of the last remnants of natural lowland heath, and I was one of those strange young teenagers who spent most of her summers not trying on miniskirts and lipstick, but either knee deep in heather and gorse looking for wildlife, or bringing home lizards, frogs and newts “to populate the garden”, to the horror of my mother, who was terrified of them. Back in the 1960s and early 1970s, no one I knew kept reptiles in captivity. But I loved the little wild ones.
2. Is there any particular reason or history behind your interest in researching about UVB?
Years ago, when our first much-loved bearded dragon, Pog, developed metabolic bone disorder despite the use of a supposedly high-quality UV lamp, I was devastated. I knew little about UV light, and I had relied upon the product advertisements. After researching, I was astonished to discover how little good information on UV lighting was known.
In 2004, I came across a new Internet mailing list being set up by hobbyists in the USA http://pets.groups.yahoo.com/group/UVB_Meter_Owners.
There, I heard about a hand-held UVB meter available in the USA; and I read about a new mercury vapor lamp called a ReptileUV MegaRay, that Bob MacCargar had invented. I asked him about his lamp. To my amazement, he offered to send me a sample.
On the mailing list were two chameleon owners from the UK - Andy Beveridge and Rob Lane. Rob imported the very first Solarmeter 6.2 UVB meters into the UK. And, we began testing UV lamps, along with fellow herp keeper Rachel Hitch.
We launched the website www.uvguide.co.uk on 26th July 2005. Recent involvement with a number of zoos and research groups worldwide has greatly broadened the scope of the project. Contacts include veterinarians, zoo keepers, herpetologists, conservationists, major reptile lighting manufacturers and distributors, and many enthusiastic keepers and hobbyists who are working with us to improve the lives of reptiles in captivity. Over the years, Rob and Rachel have moved on to other things. Andy is our technical expert, and taught me how to use his two new spectrometers; I've taken over almost all the lamp testing now.
We now have a range of meters as well as the spectrometers, and it's not just UVB I'm measuring, but the whole solar spectrum and its artificial equivalents. Reptiles are quite literally "solar powered", and it is exciting to be learning so much about different aspects of their lives.
3. Herp hobbyists always strive to find a perfect light for our pets. For new reptile keepers, what are the components of Sunlight that needed by solar powered reptiles?
In a word: everything! Reptiles are very sensitive to all aspects of sunlight. Sunlight is a radiant energy, extending from the shortest UVB wavelengths that the atmosphere lets through (around 290 - 295nm) up to UVA and visible light, right up to infrared, which we think of as radiant heat. All of these parts of the spectrum are vital to reptiles.
UVB is needed for vitamin D3 synthesis in the skin. It also has direct effects upon the immune system and skin cell division, and may even enable synthesis of endorphins - the "feel-good factor" of sunshine.
Short-wavelength UVA works alongside UVB in preventing overproduction of D3 and also has a protective effect against cell damage from UV light. Both UVA and UVB stimulate long-term changes in the production of melanin and, possibly, other pigments in the chromatophores.
Longer wavelength UVA (from about 350nm) is visible to reptiles - it is a "color" in their rainbow. Iridophores can reflect it; certainly many reptiles have UVA markings as a result. UVA is therefore a necessary component in reptile lighting.
What about visible light? We think we know why this is important to a reptile.... for vision. But that's only half the story. Light penetrates through the body of a reptile - through the skull - and light-sensitive cells in the brain. In those species, which have one, the parietal eye (third eye) responds also to green and blue light. These light-sensitive cells then relay information about the intensity and duration of the light to the parts of the brain which control diurnal and annual circadian rhythms - setting the body clocks for sleeping, waking, activity levels, seasonal behavior.
Another element to consider is infrared. Although it is invisible to us, infrared is readily experienced by all species as radiant heat. It is absolutely vital to all basking reptiles; behavioral studies suggest that they associate it with bright visible light - presumably because in nature, that's what sunlight is! I will also add that the final stage of vitamin D3 synthesis requires warmth, so for basking species, UVB lamps should be positioned over the basking zone.
4. Beside the major components UVB and UVA, your researches made me aware of another components that I often neglect, which are spectra and intensity of light. How important are those two in successful keeping of our reptile pets?
Anecdotal evidence suggests that reptiles are attracted to natural sunlight in preference to artificial light, and many keepers report astonishing changes in activity levels when reptiles are given access to natural daylight. Both the intensity of the light and the quality of the spectrum are probably playing a part. Since every reptile has evolved to thrive best in its natural habitat, I am absolutely convinced that replicating the natural lighting of a species in its microhabitat is a major key to success.
First, lets talk about the spectra.
Sunlight produces a perfect "rainbow" - the spectrum contains vast amounts of light in all wavelengths - all colors. Artificial light sources are very different to natural sunlight.
Incandescent lamps (tungsten and halogen "basking lamps") have continuous spectra (light in all wavelengths, rather like sunlight), but the shortest wavelengths are largely absent. There's no UVB, only small amounts of long-wavelength UVA and not a lot of purple and blue. So they are great for providing yellow, red and infrared, but little else.
Fluorescent tubes and compact lamps rely upon mercury vapor and phosphors to produce light. These don't produce continuous spectra - the easiest way to think of their light is in terms of a small number of "spikes" of light in a few basic colors - purple, blue, green, yellow - which the human eye and brain blends together, so we think we see white. So-called 'Daylight' phosphors produce slightly more continuous spectra with some light in the wavelengths between the "spikes"; other phosphors produce light in the UVA and UVB ranges.
Unfortunately, it's hard to know what a reptile actually sees when it looks at fluorescent tubes. Most reptile eyes have four color cones in the retina, responding to different wavelengths from our three. Does he see the light as white? Or does it have a weird color cast? We do not know.
Mercury vapor lamps (MV) don't usually have phosphors, so the main visible light is solely from the "spikes". If the lamp is self-ballasted, there's also a tungsten filament so there's a little yellow and red from that; but it doesn't improve the color balance of these lamps very much. Even to human eyes, these lamps produce light that never looks quite right.
A fluorescent lamp or MV lamp can be combined with an incandescent lamp, to get the best of both worlds. The tubes or mercury vapor lamps provide the UVB, UVA and most of the blues; the incandescent lamps add yellows and reds. It's not ideal, but it's an improvement over either lamp on its own. Friends of mine who keep chameleons have reported great success with both of these "combos," with the actual lamps chosen to provide appropriate levels of UV, heat and light for the relevant species, of course.
Metal halides may be the best solution to date. They operate on the same principle as the MV lamp, but they produce many "spikes" representing most colors across the entire spectrum. Some "Daylight" versions such as the Iwasaki/ Eye Lighting Color Arc 6500K lamp have spectra that, in the visible range, are very much like the sun. My colleague Andy Beveridge was astonished at the positive way his C. quadricornis responded to light from metal halides.
Unfortunately there are very few of these, which have been designed to emit UVB as well. ReptileUV are developing a UVB-emitting halide in their "MegaRay" range, which looks very promising. In Europe, Lucky Reptile (a German company) has launched a range known as the "Bright Sun UV" series. The spectra of these also look promising. Long-term studies are under way here, with samples from both of these companies.
In the meantime, excellent results should be possible using high quality UVB fluorescent tubes in combination with metal halides. Of course, once again, the intensity of light and of UV from such combination must be appropriate for the species.
Which brings me on to the next point: the intensity.
Our eyes are designed with pupils, to control the amount of light reaching the retina and keep the light level inside the eye within strict limits, to optimize vision. That is why we have no problems living indoors all day with approximate light levels of 1,000 lux, and are not consciously aware that this is little better than outdoor light a few moments after sunrise. And, yet at mid-day, outdoors, bright sunlight may provide 100,000 to 150,000 lux. Reptile eyes can adjust to the light just like ours. So what is the problem, once the light in the vivarium has a reasonably natural spectrum?
This is the point at which I like to speculate, because I know of no direct evidence to support my theory. However, consider this: The light-sensitive cells in the parietal eye and in the brain itself do not have a pupil to shield them. They are designed to register the intensity of natural sunlight.
The lizard evolved to walk out under the sun. if 100,000 lux shines down upon the top of his head, how many lux do you think flood through his skin, through his skull bones or the gaps between them, and reach the parts of his brain that program his activity levels and set his body clocks, stimulate serotonin synthesis, and tell him "hey, it's mid-day and it's mid-summer"?
Now put him in a cage and give him only a fluorescent lamp that emits just 500 lux at 12 inches distance. How many lux reach those light-sensitive cells now?
I am not saying we need to re-create the full brilliance of the mid-day sun indoors, even for the most hardened desert sun-worshipper. But, I do think we need to throw out any notion that reptiles - even crepuscular species - can be kept in gloomy tanks with just a ceramic heater and a dim fluorescent tube. Even nocturnal species may peer from their daytime hiding places at the bright sunlight outside.
Drs. Lynnette Sievert and Victor Hutchison in Oklahoma conducted a research over 20 years ago. They put Tokay geckos in three different situations. In one, there was only diffuse, soft lighting throughout the enclosure during the 12-hour day. In the second, there was a very bright light over the warm end of the tank, and in the third, the bright light was over the cold end - something that wouldn't happen in nature. The geckos, being nocturnal, didn't do a great deal when the lights were on. But they were markedly affected by what they perceived. The "diffuse light" and "bright warm light" groups showed clear differences in their body temperatures during the day and at night - they thermoregulated more accurately, and maintained their body temperature higher at night than they did during the day. But the "bright cold light" group behaved quite differently. Their body temperatures hardly varied between day and night, and they actually thermoregulated less accurately during their nightly activity period.
To be continued to Part II----------------
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