That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

The technology behind amphibian and reptile lighting has come a long way since I began working at the Bronx Zoo, when “black lights” and the sun were our only UVB (Ultra Violet B radiation) options.  Today I’ll review an important herp husbandry innovation, the compact UVB fluorescent bulb (note: bulbs are referred to as “lamps” in technical papers).  My experiences have been positive, but some reptile-keepers have raised concerns, so I’ll address them as well. Please be sure to post your experiences and ideas below, as we still have much to learn about this important topic.

Uploaded to Wikipedia Commons by Dave Pape

Reptiles, UVB and UVA: a Quick Primer

Most heliothermic (basking) lizards, turtles, and crocodilians need exposure to UVB light rays with a wavelength of 290-315 nanometers in order to synthesize Vitamin D3 in their skin.  Vitamin D3 allows these animals to utilize dietary calcium.  Without D3, dietary calcium is not metabolized and metabolic bone disease sets in.  Snakes, highly-aquatic turtles, nocturnal lizards, most amphibians, and certain others can make use of dietary Vitamin D, but most basking species rely on the skin-synthesized form. Read More »

Our understanding of the role that Ultraviolet B Light plays in the lives of reptiles and amphibians has increased greatly over the last few decades, but we still have much to learn about the needs of individual species. A good deal of conflicting information has been published, and opinions differ even among my well-experienced herpetologist colleagues. Today I’ll provide some basic information on UVB light in natural and captive situations, including some tips as to how best to provide it to the animals under your care. I’d like to stress that many variables will affect your individual situation…please post below for specific information.

What is Ultraviolet B (UVB) Light?

The various types of light are characterized by different wavelengths, which are expressed in nanometers (nm). There are three types of Ultraviolet Light, two of which are important to reptile and amphibian husbandry.

Uploaded to Wikipedia Commons by Gary2863 at en.wikipedia

UVB Light has a wavelength of 280- 320 nm. Many reptiles synthesize Vitamin D3 (or, more specifically, Pre-Vitamin D/Cholecalciferol) in their skin when exposed to UVB light. The optimum range for Vitamin D3 synthesis in reptiles is 290-315 nm.

Read More »

Last time I reported on the Staten Islands Zoo’s use of the Zoo Med 10.0 High Output UVB Lamp (Please see Part I of this article). Today I’d like to provide some specifics concerning tests carried out there.

Test Results
The UVB output readings recorded at the Staten Island Zoo are as follows (note: measurements are expressed in microwatts per centimeter squared, the standard for measuring UVB output):

Zoo Med Reptisun 10.0 High Output UVB Lamp

Zoo Med Reptisun 5.0 UVB Lamp

As you can see, the basking site’s distance from the lamp has a major impact upon UVB exposure, as does the screen cover’s deflection of light rays. With a bit of creativity, basking spots within 6 inches of the lamp can be arranged in most situations, and this is certainly the way to go for many species. Where safe to do so, dispensing with the screen cover is another option.

Using a Separate Basking Enclosure
If a 6-inch basking site or uncovered top are not feasible in your pet’s terrarium, consider the possibility of utilizing a separate basking enclosure for a few hours each day. When keeping young radiated and star tortoises in high-topped zoo exhibits, where adequate UVB exposure was not possible, I rotated the animals into a low, uncovered container every day or so, and achieved excellent results.

If you go this route, be sure to keep your pet’s individual needs and temperament in mind. For example, a simple, open container that might suit a Greek tortoise would likely cause a good deal stress to a flat-rock lizard. High strung or secretive animals must be made to feel secure in the basking enclosure, or you may do more harm than good.

Reflectors and UVB Output
The group UV Guide UK has found that simply mounting the lamp within a metal reflector nearly doubles the UVB light that is available to basking animals. In addition to focusing all of the lamp’s light into the terrarium, I imagine that the reflector also helps by deflecting back some of the light that has bounced off screen tops or other structures.

An informative article on the role of UVB and basking behavior in Vitamin D synthesis is posted at:
http://www.uvguide.co.uk/vitdpathway.htm

We have learned a great deal about the Ultraviolet B (UVB) light requirements of reptiles in recent years. However, the actual process of providing our pets with UVB of the correct wavelength (290-315 nanometers) remains fraught with confusion.

While helping to set up the new reptile house at New York City’s Staten Island Zoo (former stomping grounds of famed herpetologist Carl Kauffeld), I spoke with several pioneering researchers in the field of reptile UVB requirements, and have since monitored the building’s exhibits.

Recent Tests at the Staten Island Zoo
Recently, the zoo’s reptile keepers ran some tests in order to measure the UVB output of fluorescent lamps (bulbs) used in some of the exhibits and holding cages. While mercury vapor lamps often provide more UVB over a greater range, they are sometimes unsuitable for small cages, or for use with certain species. This study focused on fluorescent lamps, which are commonly used by pet keepers as well.

Using a UVB meter, the staff found that the Zoo Med Reptisun 10.0 High Output UVB Lamp provided high levels of UVB, with the Zoo Med Reptisun 5.0 UVB Lamp being valuable in some situations as well.

Earlier Research on Zoo Med Lamps
I did a bit of research, and learned that a group known as UV Guide UK (please see below) had earlier cited research showing that the Reptisun 5.0 (the 10.0 was not tested) scored highest of all fluorescent tubes in what is known as the D3 Index (the projected ability of lamp to foster Vitamin D synthesis). UV Guide UK also found that the Zoo Med 10.0 and 5.0 lamps lead other fluorescents in UVB output.

Zoo Med Lamps on Lizard Exhibits
The Staten Island Zoo currently uses the Zoo Med 10.0 High Output UVB Lamp with a number of lizards, including such sensitive species as the crevice spiny swift (Sceloporus poinsetti) and the Texas horned lizard (Phrynosoma cornutum).

Check out the specifics of the UVB output readings recorded at the zoo, and take a look at a simple method of increasing the output of any UVB lamp at part II of this article.

You can read more about the work of UV Guide UK, including the tests mentioned, at the following site (Note: the original tests were in 2005…the Zoo Med Lamps have been upgraded in the interim).