Of all the difficulties
encountered by turtle enthusiasts, that of raising healthy young animals
without carapace deformity is without doubt the most problematic. It is
not that information on this subject is absent, but more a case of so
much of that information being contradictory; the newcomer to breeding
turtles may be forgiven for feeling confused. The following guide-lines
have been developed and tested over 8 years with a variety of species
including Testudo graeca, T. hermanni, T. ibera,
T. marginata, T. horsfieldi, Geochelone pardalis,
G. sulcata, G. (Chelonoidis) carbonaria, G. (C).
denticulata, G. (C). chilensis and Geochelone gigantea.
We have not had the opportunity to implement this juvenile feeding program
with Xerobates or Gopherus spp. as there are very few examples
of these in captivity in Europe - however, their dietary requirements
are not vastly different to the temperate Testudo and sub-tropical
Geochelone species given above and with minor adaptions to the
regime equally good results should be obtained.
Before turning to the
positive steps which can be taken to ensure a natural, healthy growth
pattern it is worth looking in some detail at the causes and effects of
incorrect dietary management. These may be summarised as follows:
Excessive
growth
Most
tortoises and turtles, will, if overfed either in terms of sheer quantity
or quality of feed, demonstrate a quite phenomenal growth rate out of
all proportion to that attained under natural conditions within the same
time scale. In the case of hatchlings, after 12 months, captive bred specimens
may be 300 or even 500% larger than wild equivalents of the same age.
This 'gain' is not without its costs. Greatly accelerated growth of this
order places a considerable strain upon the overall metabolism, and further
results in an extremely high (and often in practice, often unattainable)
demand for sufficient mineral trace elements to permit bone formation.
Some species are worse than others in this respect - Testudo hermanni
hatchlings for example are notoriously voracious. New evidence also suggests
that hatchlings and juveniles have a higher digestive efficiency than
adults; in other words, they need to eat less for the same benefit. This
also means that if they overeat, the results will be far worse. This evidence
is backed up by observation. It is indeed the case that over-fed juveniles
tend to have very poor long-term survival prospects.
Lumpy shells
This problem
is closely associated with excessive growth. Lumpy shells are caused directly
by providing too much dietary protein, by overfeeding and by an incorrect
balance of calcium, phosphorous and vitamin D3. The problem is entirely
preventable with good dietary management.
Swollen eyes and
poor skin condition
Tortoises
in general do not make good vivarium animals. They react quickly (and
badly) to incorrect environmental conditions. If subjected to conditions
which are either too dry or too damp then eye, nose and skin problems
are rapidly encountered.
Constructive Guidelines
The following
basic guide-lines are brief, but effective. For more information on specific
topics please see other caresheets in this series or consult the recommended
reference works.
Feeding frequency
Feed once
per day only. Do not overfeed. It is better for hatchlings to be slightly
hungry than over-fed. Tortoises which are over-fed are lethargic and unhealthy.
Over-fed hatchlings will grow too rapidly and may develop 'lumpy' shells.
Dietary content
Avoid feeding
excessive quantities of fruits or 'soft' leaves such as lettuce - coarse
weeds (vetches, dandelions, grasses etc.) are much better. These not only
tend to have the correct calcium:phosphorus balance, but they are also
high in fibre. This latter is essential to healthy gut function. We feed
our own captive-bred hatchlings exclusively on a 'wild flower' diet of
hand-picked 'weeds'. The difference this makes to overall health is simply
remarkable. The droppings are perfectly formed and diarrhoea is non-existent.
Contrast this with the results obtained on a fruit/lettuce/tomato diet!
We find this diet equally excellent for our Leopard and Redfoot tortoises
too.
Calcium
& supplements
We use and recommend 'Nutrobal' [a general animal multivitamin and
calcium supplement] as a dietary supplement for hatchlings, rapidly growing
juveniles, and egg laying females. This is lightly dusted onto each meal.
It ensures that adequate calcium is available at all times. It is our
experience that 'Vionate', another regularly used supplement, whilst adequate
for routine use with adults, is not sufficiently high in calcium to guarantee
good bone development in hatchlings. [A good mammal or human multivitamin
supplement may be used with an additional calcium supplement added to
the food.]
Things to avoid
The following
items should be excluded entirely from the diets of Mediterranean species;
meat; peas; beans; avocado; banana and cheese (yes, this latter has seriously
been recommended as a suitable food for tortoises!).
In the case of Redfoot
and Hingeback tortoises, some low fat higher protein foods should be given
occasionally - rehydrated dried cat or trout pellets are recommended.
High fat tinned pet foods are not suitable (unlike Mediterranean tortoises,
some tropical and sub tropical tortoises regularly eat snails and carrion).
Housing
An open-topped
housing method is much better than an enclosed 'fish-tank' type vivarium.
In fact, provided good physical protection can be attained, the sooner
(Mediterranean species) hatchlings can be housed out of doors the better.
Certainly, in spring, summer and on warm autumn days they will do far
better outside than if confined under artificial conditions in a vivarium.
Be sure to make any such enclosure not only escape proof but also predator
proof - birds and rats don't treat captive tortoises any different than
wild ones and regard small tortoises as a tasty morsel!. A strong covering
of wire mesh will ensure adequate protection however. A natural, earthen
base is best and will allow the juveniles to express their natural desire
to dig and burrow. Some plant cover is also essential. Such an outside
terrarium is infinitely better than even the most carefully constructed
of interior vivariums. In this sort of exterior housing hatchlings will
experience natural sunlight and rain; both of these provide much stimulation.
Compare the behaviour patterns of juveniles housed in this way with those
kept permanently indoors under artificial conditions.
Obviously, in very poor
weather juveniles will require some indoor retreat. But try to keep this
as light and well ventilated as possible. An open-topped 'pen' arrangement
is definitely recommended over enclosed vivariums. Over-drying of eyes
and skin is a major problem in enclosed vivaria.
To Summarise
Don't overfeed
Avoid high fat, high
protein foods
Choose high fibre, high
calcium 'natural' foods
Use a good quality calcium/D3
additive
Provide as much access
to natural light as possible
To avoid disease, do
not mix hatchlings with adults
Adopt good hygiene measures
at all times
Make use of a safe outdoor
terrarium as often as the weather allows
Provide a natural day/night
cycle both in terms of temperature and light
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