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| PET GAZETTE | REPTILES
PET GAZETTE |
THE D3 CYCLE
T
he D3 Cycle is a chemical and
hormonal change in the body
of an animal, which goes on
to produce vitamin D3. This
is a biological process that is
dependent on many external
factors including access to natural light, heat,
cool and rest.
Some reptile keepers assume that you
could provide a lower index of power for
a longer period each day over the whole
enclosure and then bolster the D3 provision
with a reliance upon oral D3. As you will
know, being un-dosed and un-dosable and
with the threat of under or over provision this
can be problematic. It also does not provide
the animal with the ability to self-regulate.
Part of the D3 cycle is dependent on having
access to graduated powerzones and total
darkness. When we then factor in normal rest
and hiding, there is a real chance of under
provision as the animal spends time away
from exposure.
In my view, the most accurate way to
provide light and energy from light to a
captive animal is to give a measured dose at
a safe distance from the animal and over a
dedicated area. We must therefore provide
an area of emission that will cover the animal
from nose to vent at a minimum. This can
then be matched with a million graduations
of power as the animal moves away from
the basking zone where the heat and UV is
strongest and away into partial shade and
shade (rock scatter illumination).
As an example, in a 5’ vivarium that is
30” high I would use a 39w 14 percent
UVB DragonLamp fitted with its reflector
to the roof and as far into the hot side as
possible. I would then use natural slatework
and branches to build a climbing platform
under that basking zone so that the distance
between the lamp and the animal’s head is
around 15-16”. (If the internal space is 29” we
As technology advances, keepers are able to replicate a reptile’s
natural environment. In the third installment of his ongoing series,
John Courteney-Smith MRSB shares his tips on the D3 cycle
can allow for 1” of natural substrate at the
thinnest point, then a decorative height of
12” to the top of the basking zone, leaving
15-16” of free space between the lamp and
the dragon.) This will allow the dragon to
climb upwards and to use the energy as
needed. It will also provide good access to
lower powers of light, right through to total
shade at the cool end where a suitable hide
or burrow is also supplied. This upper index
basking zone can be provided for eight to
ten hours a day leading into a dusk period
of feeding before total darkness. Ideally all
visible light should be switched off and the
enclosure covered to provide total darkness
over the night. You could also suggest the
use of a 55w D3+UVFLOOD and increase the
height of the basking platform to 15-16”, the
result would be the same.
QUALITY OF LIGHT
What about quantity of light? The sun is very
bright, many, many times brighter than we
can re-create in captivity with lamps. These
animals have developed a use for and a level
of protection against this ‘light’(full-spectrum).
This includes a use for light quantity, UV
and heat-IR. The skin is thickened in basking
species allowing them to spend time in
strong exposure and protecting them from
burning. In most arid species that openly bask
there is also the previously mentioned broad
eyebrows, these protect the eyes from strong
light coming from above. These are natural
developments which should also be taken
into mind in captivity.
If they are equipped to use sources of
light that are many times brighter in terms
of ‘Lumens or Lux’ than we, as keepers, can
provide it does not make sense to say that
our vivarium lighting is too bright. The
potential danger is, of course, ill-fitted or
unnatural light sources. The biggest risk
comes from lamps that are fitted in a way
“REPTILES NEED ADEQUATE QUANTITIES OF LIGHT (WHICH IS
MEASURED IN LUMENS PER SQUARE METRE OR LUX) IN ORDER TO
‘ACTIVATE’ THE PINEAL EYE ON TOP OF THE HEAD. THIS HAS BEEN
LINKED TO INCREASES IN NATURAL BEHAVIOUR AND FURTHER
ENSURING THE COMPLETION OF NORMAL BIOLOGICAL
PROCESSES. THE EXTRA LIGHT FROM A HYBRID
BETWEEN A HIGH OUTPUT (HO) T5 SOURCE AND
SECONDARY ‘LIGHT ONLY’, SOURCES SUCH AS
JUNGLE DAWN LED CAN HELP GREATLY HERE.”
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August 2017
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37
where the light can hit the animal side on, via
glare, particularly in T8 systems.
Then we have a risk from non-terrestrial
wavelengths, namely UVC. UVC is not
found on earth, being filtered out by the
atmosphere, and causes damage at a cellular
level. It is to be avoided at all costs in all
lighting that life is exposed to. We also have a
risk of over illumination, if a light source was
used that was brighter than the actual sun
and that the animal could not regulate away
from it would pose a very real risk of damage
from glare.
To conclude, a high output T5 lamp
system with a suitable percentage of UVB is
far more effective in terms of light quantity
and UV protection if it is fitted at the correct
distances and thoughtfully. It allows retailers
and keepers to provide wild-like indexes
of power at a greater and therefore safer
distance from the lamp to the animal. It is
also flicker free and has a usable UV potency
(in terms of Arcadia Reptile lamps) for one
whole year of use.
OPTIONS FOR RETAILERS
At a retail level, you have three main lighting
options to choose from. ‘Plug and play’
types like the Slimline fitting is one option,
a separate system of a lamp, reflector and
controller is right for some or indeed the
single cable, easy to fit D3+ UVFLOOD system
in either 24 or 55 watts can be very useful,
depending on the enclosure size and
animal type.
Index provision per area should be
checked with a Solarmeter 6.5 to be sure of
an accurate supply. These can be checked in-
store or sold to the customer or indeed hired
out to allow your customer base to check
their own systems.
John Courteney-Smith’s latest
fact-packed book, Bio-Activity and
the Theory of Wild Re-Creation, is
essential reading for reptile keepers
and members of the trade. For more
information go to www.arcadia-sales.
com/collections/reptile-books.
To listen to John’s free podcasts visit
www.chameleonbreeder.com/podcast/
ep-55-mbd-uvb-with-john-courteney-
smith/
August 2017