Exotics and Birds
Tortoise Care
Avoiding Problems
Unfortunately the most common cause of illness in all species of tortoise is incorrect husbandry, for example unsuitable heat, light and humidity levels together with poor nutrition. While tortoises should ideally be maintained outside in large enclosures for most of the year, with the British climate, this is not possible and indoor accommodation is required for at least part of the year. Many tortoise owners are not used to the idea of manipulating lighting, temperature and humidity in order to provide an optimal environment for their animal. Whilst some tortoises have survived for decades under these conditions, owners should realise that by keeping them under the influence of the British climate all year round, without any artificial heating and lighting, they are subjecting their tortoise to conditions which are very different from those which they have evolved to cope with. These conditions, especially in combination with a poor diet will in many cases lead to chronic disease which has often been developing over many years before the tortoise becomes obviously ill.
ACCOMMODATION
Outdoor accommodation
In the summer when the weather is warm Mediterranean tortoises should be kept outside in large well-drained enclosures in sunny locations, which ideally should be planted with a variety of edible plants (see table below for appropriate plants). Wild tortoises are found in scrubland areas where they range widely feeding on high fibre vegetation. A small pen on a lawn is not a suitable substitute. Tortoises are surprisingly agile and are often adept at climbing and burrowing. Males in particular may be hyperactive during the breeding season and pace the perimeter of their enclosure. For this reason outdoor pens must be well designed to prevent escape and to protect the animals from predators such as dogs, foxes, rats and birds. Tortoises are intolerant of damp and sheltered sleeping quarters should be provided.
Indoor accommodation
If left to the influence of the British climate, tortoises WILL hibernate for 5 or 6 months of the year which is twice as long as wild tortoises hibernate. (Some tortoises e.g. Tunisian spur-thighed tortoises do not hibernate at all in the wild.) Even in the summer the temperature will not always be high enough in this country for tortoises to do well. All tortoise keepers should have available suitable indoor accommodation for use when outdoor conditions are not suitable e.g. in the early spring after emerging from hibernation or during cold periods in the summer.
Indoor accommodation may be provided by utilising greenhouses, conservatories or polytunnels, or by setting up pens inside the house. Good ventilation is essential and for this reason glass tanks and the reptile type vivarium are generally unsuitable. Easily disinfected open-topped pens are recommended. Table-top enclosures are very good and can easily be heat supplemented – see the websites recommended above for design ideas.
Substrate
The correct choice and depth of substrate will help in maintaining an appropriate microclimate. Juvenile Mediterranean species and Horsfield tortoises enjoy burrowing and should be provided with a substrate that permits this. Substrates commonly used for
tortoises include alfafa/grass pellets, bark chippings, hemp substrates, newspaper, astroturf, indoor/outdoor carpeting and peat/soil mixtures. Sand, cat litter, and crushed corn cob or walnut shells are not recommended due to the risk of ingestion and intestinal blockage. Food should be provided on tiles or in dishes to reduce the chance of ingestion of
substrate with food items.
Stocking Density and Quarantine
All tortoises are best kept in small groups of one species and no new animals should be introduced without a lengthy period of quarantine. With the high incidence of viral disease in tortoises, even individuals isolated or quarantined for several years cannot be guaranteed as free from infectious agents.
Overcrowding should be avoided and animals of different sizes kept apart. Tortoises seldom thrive in groups of more than 8.
HEATING
Like all reptiles, tortoises must be given the opportunity to regulate their body temperature by providing a gradient of temperatures within their preferred optimum temperature zone, POTZ, (20-32°C). The preferred body temperature, PBT of a tortoise is near the upper end of this gradient, (26-30°C) and in order for its digestion and other bodily processes to function efficiently every tortoise must be able to attain this temperature by basking in
a radiant heat source during the day.
Heat Sources
Both infra-red ceramic heaters and ordinary spotlights are suitable for this purpose. 40–100W bulbs can be used depending on the height above the tortoise and the size of the enclosure (see later notes under lighting for information on PowerSunlamps (Zoomed) which provide both heat and ultraviolet light). Allowing a tortoise to wander round the house will not allow it to reach the correct body temperature. Eating behaviour and activity increase
dramatically when a tortoise is maintained above 26°C. The same tortoise at 21°C may move around but fail to feed properly. At night temperatures can be allowed to fall. As well as a basking lamp, other types of heating may be needed to keep the ambient room temperature high enough. Temperatures should be monitored by the use of thermometers,
which record both maximum and minimum temperatures.
Do not heat tortoises from below using heat mats. If Heat mats are utilized they best placed on vivarium walls where heat radiates out. This avoids hot spots and ventral heating of the digestive tract.
Lighting
As mentioned above, calcium is absorbed from the digestive tract under the influence of vitamin D3.
Testudo tortoises can produce their own vitamin D3 via a complex biochemical pathway involving the action of UV light on cholesterol in the skin and then further processing by the liver and kidneys.
Light can be divided into infra-red, visible light and ultraviolet. Ultra-violet light is further divided into UVA, B and C. UVB (which consists of wavelengths between 280 and 315nm) is the range needed for vitamin D3 production. In the wild, sunlight provides the source of ultraviolet light, however tortoises housed indoors will need artificial UVB lighting if they
are to produce their own vitamin D3. This also applies to tortoises kept in greenhouses or
conservatories as UVB does not pass through glass.
There are various ‘full spectrum’ UV lights available for reptiles, however they differ in the amount and wavelength of ultraviolet B which they emit. One confusing fact is that some incandescent lamps marketed as full-spectrum reptile lights do not emit any UVB at all! They provide the full-spectrum of visible light only. Of the UVB lights available it is difficult to obtain comparative data, however the Reptisun 5.0 UVB lights (Zoo-Med), which are
fluorescent tubes, and the Activa (Sylvania) reptile D3 lamps were previously generally rated as the best available. However, even these lights have their drawbacks in that the UV B wavelengths that they emit are of relatively low intensities. They must therefore be placed in close proximity (six inches) to the tortoise.
In addition the UVB output declines rapidly after 6 to 9 months due to build-up of deposits inside the tube and they therefore need to be replaced at least annually, even though they are still emitting visible light. However, recently PowerSun (ZooMed) mercury vapour lamps providing both heat and UVB have been developed. These have superseded many of the UVB only lamps.
These full spectrum lights also emit UVA radiation which, although not needed for vitamin D3 synthesis, has been reported as being beneficial behaviourally and psychologically for many reptiles. Obviously, all captive tortoises should be exposed to natural sunlight whenever the weather is warm enough.
Photoperiods (ie the length of time lighting is provided) must be suitable for the species concerned and for species from temperate climates would naturally vary throughout the year.
DIET
Wild tortoises feed on a wide range of vegetation, which is high in fibre and calcium, and low in fat, protein and phosphorus. The ideal diet in captivity is one that mimics that of tortoises in the wild as closely as possible. If this is not possible, as wide a variety of available substitutes as possible should be fed.
Over-reliance on a small number of dietary components, (such as the tomato, lettuce and
cucumber only diet!) should be avoided. Tortoises will forage for themselves if provided with a suitably planted large enclosure containing edible weeds, flowers and grasses. However most owners will find themselves having to rely on grocery greens and vegetables during at least part of the year.
Inappropriate diets
• Beware of poisonous plants such as daffodils and other bulbs, onions, potatoes, rhubarb, buttercup and yew
• Complete pelleted diets are not recommended as a major dietary constituent.
• Animal protein such as meat, including cat and dog food, cheese and milk should never be fed.
Nutritional problems are an avoidable but common cause of disease in captive tortoises and can result from either deficiency or excess of various essential vitamins and minerals from feeding an incorrect diet.
Excessive amounts of protein will also cause problems. Signs of nutritional disease are often seen at times of metabolic stress, for example growth in juveniles, or in females producing eggs and are more likely to develop if the tortoise is not kept under the correct environmental conditions.
Calcium Management
A dietary supply of calcium is important for a variety of processes, including growth of the shell and skeleton, egg production and muscular function.
Calcium metabolism and control is a complicated process relying on several organ systems and the interrelated actions of various hormones. Calcium is obtained from the food but how much of the calcium content is available to the animal depends on the ratio of calcium to phosphate in the food and the presence of calcium and phosphate binding chemicals such as oxalates. Ingested calcium is absorbed from the digestive tract under the influence of parathyroid hormone and vitamin D3. Tortoises make their own vitamin D3 after exposure to UV light from the sun. In Britain where tortoises need to be maintained inside for part of the year, it is recommended that artificial UV lighting is provided during this period (see above).
When considering the calcium content of the diet, it is not the total amount of calcium but the ratio of calcium to phosphorus that is important. It is generally recommended that herbivorous reptiles should be fed a diet with a calcium : phosphorus ratio of at least
1.5 - 2 : 1. However, natural diets of wild tortoises typically contain a calcium :
phosphorus ratio of at least 4 - 1 and it is possible that tortoises have a higher dietary calcium requirement than some other reptiles.
In comparison to natural forage such as weeds, grocery greens are generally higher in protein and lower in fibre with, in many cases an unsuitable and often inverse calcium : phosphorus ratio. For example, whereas dandelions have a calcium : phosphorus ratio of 3:1, iceberg lettuce has an inverse ratio of 0.8:1. This means that calcium supplementation is essential.
Calcium Supplementation
Unfortunately, many of the supplements available do not have a high enough calcium:phosphorus ratio to balance deficiencies in the diet. For example Reptivite (ZooMed) has a ratio of 2:1 and Vionate (Sherleys) of only 1.4:1. Nutrobal (Vetark) and Arkvits (Vetark) with ratios of 46:1 and 30:1 respectively are more suitable.
Daily supplementation may be necessary in reproductively active females or actively growing
juveniles, as well as in those animals with nutritional disease. In other tortoises supplements should not be necessary more than every other day and a healthy tortoise grazing natural forage in the summer, or on a balanced and varied diet composed of grocery greens with the correct calcium: phosphorus ratio may not need to be supplemented more than weekly.
A Balanced Diet
A sensible approach is to try and feed weeds and natural vegetation as much as possible along with a variety of grocery greens when necessary, each with a reasonable calcium : phosphorus ratio and to use a calcium supplement such as Nutrobal regularly.
Suitable weeds, flowers and grasses include dandelion, clover, plantains, sowthistle, rape,
vetches, dock, chickweed and dead nettles, wild pansy, hibiscus, nasturtium, bramble, mulberry and roses.
Grocery greens with a reasonable calcium : phosphorus ratio include cabbage, turnip and beet tops, mustard greens, parsley, broccoli, brussel sprouts, carrot tops, romaine lettuce (not iceberg), spring greens/collard, Swiss chard, kale, spinach, endive, watercress, chicory, mint and chinese leaves such as pak choi. This list is slightly complicated by the fact that oxalates found in spinach, Swiss chard, cabbage and beet greens bind calcium reducing its
absorption by the digestive tract. However it is thought that tortoises may have evolved an ability to deal with high levels of oxalates and as long as these items are fed sparingly as part of a varied diet they are unlikely to cause problems.
Vegetables including parsnips, swedes, cauliflower, carrots, courgettes, sweet potato, turnip and marrow can be given as up to 10% of the diet. Peas and beans are not recommended due to their higher protein content. Fruit including melon, plums, pineapple, mango, figs, grapes, tomato, apple, pear, strawberries, raspberries, cucumber, peppers, watermelon, and papaya should make up no more than 5% of the diet.
All food can be dusted with a suitable mineral and vitamin supplement, such as Nutrobal (Vetark) as discussed above.
Grocery greens, vegetables and fruits should all be washed of any potential pesticide residues. Many people advise that organic food is highly suitable and appropriate for herbivorous species.
Dietary components should be chopped or shredded and well mixed to prevent selective feeding. It is important to ensure that wild plants have not been sprayed with pesticides. Similarly it would be wise if buying grocery greens to use organic produce. All tortoises must be given regular access to fresh water for drinking and bathing.
Appendix 2: Diet advice The following dietary components are suggested at our surgery as being suitable and readily available to those maintaining captive herbivorous chelonians.
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Wild plants
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Green-leaf base
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Vegetables
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Subject to availability, wild foods are ideal components of the captive tortoise diet.
Dandelions are suitable as a healthy core food.
Caution should be taken to ensure poisonous plants listed later are not mistakenly offered.
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Green-leaf base should
comprise around 75% of the
normal diet of Mediterranean
tortoises such as Testudo
hermanni and Testudo
graeca.
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15% of the diet of
Mediterranean tortoises
should be grated or chopped
vegetable matter
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•Dandelion (Taraxacum
officianale)
•Clovers (Trifolium spp.
•Hawkbits (Leontodon spp.)
•Sowthistles (Sonchus spp.)
•Hawkweeds (Pictus spp.)
•Mallows (Malva spp.)
•Bindweeds (Calystegia
spp.)
•Sedum (Sedum spp.)
•Ivy-leaved Toadflax
(Cymbalaria muralis)
•Honeysuckle (Lonicera
periclymenum)
•Cats Ears (Hypocheris
spp.)
•Vetches (Vicinia spp.)
•Trefoils (Lotus spp)
•Bramble (Rubus
fruiticosus)
•Chickweed (Stelaria media)
•Dock (Rumex crispus)
•Plantain (Plantago spp.)
•Nettles (Lamium spp.)
•Hedge Mustard
(Sisymbrium officionale)
Source: Wild foods for
tortoises, in The Tortoise
Feeding manual (Highfield
undated)
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•Dandelion: leaves and
flowers
•Alfalfa: Fresh, Sun-cured
hay, dried leaves, pellets
•Mixed grasses: Fresh, Suncured
hay, dried leaves,
pellets
•Cabbage (mixed varieties)
•Rocket
•Clover shoots
•Kale
•Rape
•Parsley
•Watercress
•Spring greens
•Carrot tops
•Beet tops
•Sowthistle
•Turnip tops
•Chickweed
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•Beans (leaves and pods)
•Broccoli
•Brussel sprouts
•Cauliflower
•Beetroot
•Carrot
•Parsnips
•Turnip
•Marrow
•Pumpkin
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Fruits and succulents
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Garden Forage
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Fruits should be fed cautiously.
High sugar levels can encourage bacterial, mycotic and protozoal overgrowth.
This is particularly likely following antibiotic treatments.
No more than 10% of the normal diet of Mediterranean tortoises.
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It is essential to remove any
potentially toxic plants from
the garden and to avoid the
use of any chemicals such as
pesticides and slug pellets. It
is also important to retrieve
tortoises before mowing the
lawn.
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•Melon
•Tomato
•Mango
•Apple
•Pear
•Peppers
•Cucumber
•Grapes
•Mulberry
•Peach
•Apricot
•Nectarine
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•Lawn grass, clovers and
•Dandelions
•Hibiscus
•Mint
•Nasturtium
•Lilac
•Rose
•Bramble
•Flowers and their leaves
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JUVENILE CARE
Hatchlings and juvenile tortoises are commonly kept in vivariums and often maintained year round under conditions of optimal heating, lighting and food availability. They may also be given unsuitable high protein diets. This does not mimic the situation in the wild where food availability and quality may vary significantly throughout the year. In addition, young wild tortoises like adults will not be eating during hibernation in winter and/or aestivation during hot spells. As a consequence many captive juveniles achieve abnormally fast rates of growth, which may be too fast for the supply of calcium available.
Metabolic bone disease is common in these tortoises especially if given inadequate calcium or vitamin D provision, an inappropriate dietary calcium:phosphorus ratio, or lack of exposure to UV light. It can result in soft shell, shell deformity, muscular weakness, egg retention, and prolapse of organs through the cloaca. Correct nutritional and environmental management will avoid metabolic bone disease, accelerated growth and early maturity.
This involves providing a high fibre, low protein diet as for adults with a high calcium supplement such as Nutrobal (Vetark) and may include feeding every other day rather than daily.
In warm weather Testudo hatchlings can be housed outdoors with appropriate shelter and protection from predators. This allows natural grazing as well as the beneficial effects of natural sunlight and exercise.
HIBERNATION
In the UK most keepers prepare for hibernation after the autumn equinox. Persistent temperatures below 15°C in conjunction with decreasing day length will induce a tortoise kept outside to hibernate. If this is to be avoided, artificial heating and lighting in indoor
accommodation will usually need to be provided from late August onwards. Hibernating tortoises should be starved for a period of 3-4 weeks before entering hibernation, which often commences at about the third week in October. This is to make sure that there is no food in the digestive tract which could rot while the tortoise is hibernating. During this prehibernation period they should be bathed daily to encourage fluid uptake. It is important that a hibernating tortoise has a full bladder, as it can use this as a fluid store.
Hibernation should be carried out at around 5°C. This can vary by a few degrees either way but should not drop below 2°C or go above 9°C.
Fridges are very suitable and popular hibernation enclosures, providing the air is changed daily and temperature control is reliable.
Insulated boxes inside a cool building can also be used provided there is adequate monitoring of both hibernation conditions and hibernation duration. The maximum daytime and minimum night time temperatures of the hibernation chamber should be checked daily. Never allow exposure to sub-zero temperatures.
Tortoises can be handled carefully and checked even in a hibernating state. Weighing them regularly is useful. If the tortoise has urinated and lost its fluid store, it should be woken up.
Hibernating a tortoise outside is not advisable as there is a risk of frost damage, flooding and trauma from predators such as rats. In addition, if these tortoises are left to awake naturally, they will not do so until late March or early April leading to a hibernation period of almost half a year!
In the wild most tortoises will have a long period of warm weather to prepare for a short hibernation period. In Britain tortoises may be exposed to a short period of warm weather to prepare for a long period of hibernation! This results in an increased incidence of post-hibernation problems such as mouth rot and kidney disease. The recommended maximum length of hibernation is 3 months for a healthy adult tortoise. This means that most tortoises will need to be woken at the end of January or early February and kept inside in a warm
enclosure until the summer.
Upon awakening
Upon awakening, tortoises should be checked for signs disease such as mouth rot, discharge from the nose or eyes or swellings on the skin. All suspect animals should be taken immediately to a veterinarian. Healthy animals should be bathed twice daily in shallow warm water encouraging drinking and voiding of urine and faeces. They should be kept in an indoor enclosure with a basking lamp and UV light as described above. A healthy tortoise should be eating within a week of ending hibernation.
Appetite, urination, activity, defecation and thirst should be carefully monitored and recorded for at least three weeks following hibernation. Tortoises not seen to have urinated or eaten within a week of hibernation require veterinary attention, or improvements in environment.
All tortoises will benefit from an annual veterinary check-up. Many people arrange this for late summer before the tortoise goes into hibernation, since it is inadvisable to hibernate an ill tortoise. It is a good idea to take along a fresh faecal sample so that the vet can check for the presence of gastrointestinal parasites such as worms.
Useful Websites and sources of information:
- The British Chelonia Group
(http://www.britishcheloniagroup.org.uk/)
(www.tortoisetrust.org/)
- The British Association of Tortoise Keepers
(http://www.batk.org.uk/)
(http://www.chelonia.org/)
(http://www.turtlesurvival.org/)
Tortoise Hibernation Information for Owners
It is extremely important to identify the species of your tortoise before considering hibernation. The table at the end of the article gives suggested hibernation or over-wintering conditions for the species commonly encountered in the UK. This information is aimed at Testudo Species. Other species are mentioned later.
Preparation for Hibernation
In the UK most tortoise owners start to prepare for hibernation after the autumn equinox. It is recommended that tortoises should have an annual health check-up – ideally in late summer so that their general health status and suitability prior to hibernation can be
assessed. An underweight or ill tortoise should not be hibernated.
It is a good idea to take along a fresh faecal sample so that the vet can check for the presence of gastrointestinal parasites.
Once it has been established that the tortoise is suitable to hibernate, the tortoise should be starved for a period of 3-4 weeks before entering hibernation, which often starts at about the third week of October. This is to ensure that there is no food present in the tortoise’s digestive tract which could rot during hibernation.
During the pre-hibernation period they should be bathed daily to encourage fluid uptake (tortoises absorb fluids from their cloaca when in a bath, as well as enjoying a drink).
It is important that a hibernating tortoise should have a full bladder, as this can act as a fluid store.
A tortoise kept outside can be induced to hibernate by providing persistent temperatures below 15ᵒC together with decreasing day length.
Tortoises can be placed in outhouses to give increasing exposure to outdoor temperatures. The number of hours spent outside is increased over a period of three weeks and the core body temperature will drop on average by 5ᵒC per week.
Within 3 weeks the core body temperature will fall from about 26ᵒC to approx. 13ᵒC and at this point animals can be transferred to the hibernation accommodation.
If hibernation is to be avoided, eg. if the tortoise is ill or very underweight they will need to be provided with artificial heating and lighting. Indoor accommodation will usually need to be provided from late August onwards for over-wintering.
Hibernation Accommodation
Fridges are suitable hibernation enclosures.
Fridges are ideal, providing the air is changed regularly and temperature control is reliable. Small ‘Beer’ fridges are ideal for just one tortoise as they are not too large or expensive. Care should be taken to ensure that the fridge is not used for human food when not in use for your tortoise as there is a possible zoonotic risk of salmonellosis.
Temperatures can be kept stable at 5ᵒC, and humidity guaranteed. Fridges have been used without complications for a decade for Testudo sp of all sizes and ages.
Insulated boxes (a box within a box) inside a cool building can also be used provided there is adequate monitoring of both hibernation conditions and duration. Air holes should be kept to a minimum and the chamber should be carefully placed to avoid touching external walls. There should be no risk of rodent access.
We no longer trust that stable temperatures can be provided using natural ambient conditions. Therefore we encourage the use of fridges.
The maximum daytime and minimum night time temperatures of the chamber should be checked daily. Maximum /minimum thermometers are very useful for this. Never allow exposure to sub-zero temperatures – see table for different species temperature requirements. Freezing may lead to death or severe eye problems.
High humidity of the substrate (90-95%) is important to prevent excessive fluid
loss. Good ventilation should prevent mould build-up.
Tortoises can be handled carefully and checked whilst hibernating – it is useful to weigh them regularly – a hibernating tortoise should never lose more than 8-10% of its body-weight. If they do, this may be due to too high temperatures together with activity and/or fluid loss due to low humidity and/or urination. If the tortoise has urinated and lost its fluid store it should be woken up. Activity may indicate that the animal is not being maintained at a cool enough temperature. After waking at any point, tortoises should never be returned to hibernation.
OUTDOOR HIBERNATION
Hibernating a tortoise outside is not advisable as there is risk of:
• Frost Damage,
• Flooding,
• Trauma or injury by predators such as rats,
• It is impossible to monitor the tortoise during the hibernation period.
If These Tortoises are left to awaken naturally, they will not do so until late March or early April, which is far too long a period of hibernation.
Prolonged Hibernation
Prolonged hibernation, leading to a hibernation period of almost six months leaves insufficient recovery and grazing time to stabilise from one hibernation and prepare for the next hibernation. These tortoises are both physiologically challenged and weakened by such husbandry.
Many fail to adequately recover their bone marrow function (immune system) and other organ functions appropriately in the limited active time they have been given.
In the wild most tortoises will have a long period of warm weather to prepare for a short hibernation period. In the UK, tortoises may be exposed to a short period of warmer weather to prepare for a long hibernation period. This results in an increased incidence of post-hibernation problems such as mouth rot (stomatitis) and kidney disease.
The recommended maximum length of hibernation is 3 months for a healthy adult tortoise, so most will need to be woken up at the end of January or early February and kept inside in a warm enclosure until the summer.
Alternatively they can be prevented from premature hibernation and allowed to tick over between October and January on a 10 hour light cycle and alternate day feeding, with every other day bathing. Hibernation can then happen in February and March allowing animals to be recovered when food availability and outdoor conditions are improved.
Should juveniles be hibernated?
Whether or not to hibernate juveniles in their first year is a matter of some contention. Some argue that they should always be hibernated, whilst others argue that hibernation should be reserved for those over 3-4 years old. It must be noted that the growth of hibernated juveniles is usually smoother and tends to be closer to natural rates than that recorded for specimens which have been over-wintered.
As all wild juveniles will hibernate, avoiding hibernation entirely is unnatural and not without common complications such as accelerated growth and early maturity. We therefore would encourage at least a period of controlled adverse husbandry around the time of hibernation for all healthy juveniles, whatever the size, in order to prevent unrestricted growth. Generally this means preparing the animal for potential hibernation as previously described, but reviving the animal at the point it can be put into a fridge. For the stronger-willed, suitably prepared, healthy, juveniles can be put into a fridge for a very short while such as 1-3 weeks. They are easy to monitor and manage.
The key thing is not to blindly discourage hibernation in healthy juveniles and encourage optimum temperature management and nutrition 365 days a year instead, as this will result in endless maximum growth and likely deformity and ill health.
Due to their reduced body mass compared to some adults, the core temperature of juveniles is more easily influenced by external factors. Therefore temperature stability is especially important during hibernation.
Terrestrial juveniles may be allowed to bury themselves completely in a surrounding mass of substrate such as earth within a deep tray. This should help to prevent against sudden temperature fluctuations and will help to avoid dehydration.
Waking Up
Tortoises only enter or remain in hibernation whilst the temperature is within a certain range – as the temperature rises the metabolic rate returns to normal and hibernation comes to an end. Upon awakening, tortoises should be checked for signs of disease such as mouth rot, nasal discharge or skin swellings. Any tortoise showing abnormalities should be taken to a vet.
• Healthy animals should be bathed twice daily in shallow warm water encouraging drinking and voiding of urine and faeces.
• They should be kept in an indoor enclosure at 22-25ᵒC with a basking lamp and UV light.
• A healthy tortoise should be eating within a week of waking up.
• The keeper should monitor appetite, urination, activity, defaecation and thirst for at least 3 weeks post hibernation.
• Initially, succulent foods such as melon and cucumber should be offered and the diet changed back to a normal balance as soon as eating and urination are normal.
• Hand-feeding, syringe and even stomach-tube feeding may be required.
• Tortoises that have not been seen to urinate or eat within one week urgently require veterinary attention or environmental improvement.
Upon first waking from hibernation a tortoise is depleted in strength, has a low white blood cell (WBC) count and is particularly vulnerable to infection. The blood urea level is very high due to the accumulation of metabolic toxins over the hibernation period. This combination of low WBC and high blood urea, at a time when other body functions are also not at peak effectiveness does mean that should anything go wrong, the time available to treat and correct the problem is considerably less than normal. Unless the tortoise receives adequate quantities of heat and light (which must be supplied artificially in the British climate) it will refuse to eat, will use up its existing fat and energy reserves and will start to decline.
Species Requirements
Poikilothermic (previously termed ʻcold-bloodedʼ) reptiles are unable to maintain their body temperature independently of the temperature of their environment. Consequently, a number of tortoise species found in temperate areas have developed the ability to ʻshut downʼ or hibernate during the cold winter months. This conserves energy and enables the tortoise to cope through periods of natural food shortage. Conversely, some species from regions with very hot summers will aestivate through the hot periods. Indeed, some species such as the Horsfieldʼs tortoise may do both, avoiding the long winters and very hot, arid summers.
It is often not easy to generalise about which species can and cannot hibernate. In the wild, some species hibernate in parts of their natural range and remain active throughout the winter in others. Such species, including most from North Africa, should be said to have the biological capacity to hibernate, rather than always doing so. Persistent non-hibernating of captive species which would naturally hibernate in the wild can cause health problems including liver disease and reduced fertility. The British climate is obviously not suited to
tortoises and so artificial manipulation of temperature and photoperiod (daylength) and careful monitoring before, during and after hibernation is vital.
Hibernation Conditions for Different Species
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SUGGESTED HIBERNATION CONDITIONS
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SUGGESTED TEMP / RANGE °C
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Hermannʼs Tortoise
Testudo hermanni
Spur-thighed Tortoise
Testudo Graeca
Testudo ibera
Testudo whitei
Marginated Tortoise
Testudo marginata
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Starve for 3-4 weeks before hibernation. Hibernate in
a box within a box, the two separated by an insulating
material. Place in cool building or within a reliable
refrigerator. High humidity of the substrate is
important, in conjunction with good ventilation to
avoid building up of mould. Often useful to house
indoor with supplemental heat and lighting at end of
hibernation in order to restrict its duration.
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5 (2-9)
Never allow exposure to sub-zero temperatures.
Monitor maximum daytime and minimum night
time temperatures throughout hibernation.
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Tunisian Tortoise
Furculachelys nabeulensis
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Should not be hibernated
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Horsfieldʼs Tortoise
Testudo horsfieldi
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Often useful to house indoors with supplemental heat
and lighting at start and end of hibernation in order to
restrict its duration to 2-3 months. Starve for 3 weeks
before hibernation. Hibernate in a box within a box,
the two separated by an insulating material. Place in
cool building or within a reliable refrigerator.
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2-9
Never allow exposure to sub-zero temperatures.
Monitor maximum daytime and minimum night
time temperatures throughout hibernation.
|
|
Red-eared Terrapin/Slider
Trachemys scripta elegans
|
Although hardy specimens can survive mild winter
outside, this is not recommended. Outdoor pond
terrapins should be overwintered inside.
|
Varies with winter environment.
|
|
3-toed Box Turtle
Terrapene carolina
|
If maintained outdoors can be allowed short
hibernation or 2-3 months. Set up in cool room as for
Testudo spp. but place turtle in damp leaves, moss,
peat or earth in order to maintain high humidity.
Alternatively overwinter inside.
|
7-16
Never allow exposure to sub-zero temperatures.
Monitor maximum daytime and minimum night
time temperatures throughout hibernation.
|
|
Ornate Box Turtle
Terrapene ornata
|
If maintained outdoors can be allowed short
hibernation of 2-3 months. Set up in cool room as for
Testudo spp. but place turtle in damp leaves, moss,
peat or earth in order to maintain high humidity.
Alternatively overwinter inside. Note that wild turtles
in southern part of range do not hibernate.
|
Never allow exposure to sub-zero temperatures.
Monitor maximum daytime and minimum night
time temperatures throughout hibernation.
|
|
Bellʼs Hingeback Tortoise
Kinixys belliana
|
In captivity usually kept under the same conditions
year round and not hibernated. In the wild may
become inactive during the winter and this seasonal
change can be simulated in captivity in order to
encourage breeding activity in the spring.
|
Decrease in daylength from 13 to 11 hours and in
temperature from 23-32 to 18-20°C for a period of
8-10 weeks during the winter. Withhold food and
basking facilities.
|
|
Leopard Tortoise
Geochelone pardalis
|
Do not hibernate
|
|
|
African Spurred Tortoise
Geochelone sulcata
|
Do not hibernate
|
|
|
Redfoot Tortoise
Geochelone carbonaria
|
Do not hibernate
|
|
|
Yellowfoot Tortoise
Geochelone denticulata
|
Do not hibernate
|
|
|
Desert Tortoise
Gopherus agassizii
|
Starve for 3-4 weeks before hibernation. Hibernate in
a box within a box, the two separated by an insulating
material. Place in cool building or within a reliable
refrigerator
|
5 (2-9)
Never allow exposure to sub-zero temperatures.
Monitor maximum daytime and minimum night
time temperatures throughout hibernation.
|
|
Asian Box Turtles
Malayan Box Turtle
Cuora amboinensis
|
Do not hibernate
|
|
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[i] Information taken from Holly House Veterinary Surgery Care leaflets www.hollyhousevets.co.uk and the Tortoise Trust website www.tortoisetrust.org