Horsfield Tortoise natural history

Walking tanks
Horsfield tortoises are a small sized tortoise (family Testudinidae) growing from 6-10” in length and weighing from 650-1500 grams in weight. Males will be somewhat smaller than females, almost half the weight and size but they make up for this with personality, particularly during the breeding season. Males will follow a female’s scent (moving quite quickly for a tortoise) and proceed to bash and nip her into submission. Once the female has withdrawn into her shell the male will mount her. Horsfield tortoises can live anywhere from 60-80 years with appropriate care and have been known to reach 100 years of age.
Physically, horsfields are very similar to several other species of tortoise found around the world;
o a rounded carapace (top of the shell)
o a flattened plastron (underside of the shell)
o large scutes (individual plates of the shell)
o stubby legs
o fully retractable head
Their latin name Testudo horsfieldii was given in honour of the American naturalist Thomas Horsfield. Found in central Asia including the Russian steppes, Afghanistan, Iran, Uzbekistan, Pakistan and in some parts of China in hot, dry and arid regions. These tortoises have been found near deserts, grassy steppes and in mountainous areas. They are well adapted to harsh conditions such as high and low temperatures, limited water availability and low protein, high fibre foods. Horsefield tortoises are very efficient diggers and will create burrows in which to sleep, retreat from extremes of weather and hibernate through the harsh seasons. They are also very avid climbers and can scale fences in captivity, care must be taken when housing these animals in seasonal outside enclosures, as they will dig or climb their way out unless they are in secured surroundings.
With such a large, far-reaching natural range it is surprising that these little horsefield tortoises are now CITIES II listed and can no longer be collected from the wild. Due to decades of over collection for the pet trade and the more recent natural habitat destruction, horsefield tortoise are now endangered in their natural environment. Thankfully, captive breeding projects maintain the ever-increasing popularity for tortoises as pets and some have even been reintroduced to their native home. Horsefields are one of 5 different subspecies in the Testudo genus:
• T. horsfieldii – the horsfield tortoise
• T. hermanni – the herman tortoise
• T. graeca – the Greek tortoise
• T. kleinmanni – Kleinmanns tortoise
• T. marginata – the marginated tortoise
There are also three recognised subspecies of the horsfield tortoise found throughout their extensive range:
• T. horsefieldii horsfieldii
• T. horsefieldii kazachtanica
• T. horsefieldii rustmovi
There is very little physical difference between the subspecies, the differences are all regional and mostly dietary. The most commonly found and now captively bred subspecies is Testudo horsfieldii horsfieldii.
Horsfields are almost completely herbivorous, 95% of their diet consisting of leafy greens, grasses and flowers. The remaining 5% is made up of roots, dried fodder, succulents and rare, low growing fruits. They are grazers and will move continuously from one food source to another, dependent on the quality of browse they consume, they will on average eat as much as the size of their own shell per day. Due to the very low-quality nutrition that is available in their natural habitat they can be found grazing throughout the day. Horsfields will also consume their own faeces. This is known as coprophagy and is commonplace in many species of herbivore found throughout the world. This practice is to reabsorb any lost beneficial gut bacteria and absorb any remaining nutrients. Horsfield tortoises will gain much of their moisture from the food that they consume, but water should be provided in a captive environment at all times to ensure hydration. In the wild, horsfield tortoises will drink heavily when they find a water source, more often than not urinating and defecating whilst drinking.
Horsfield tortoises first arrived in the UK pet trade in the late 1960’s. They were often kept outside all year round and referred to as “garden tortoises” (they were in fact one of 3 species sold as a garden tortoise, the horsfield tortoise, the hermann tortoise and the marginated tortoise). More than 240,000 animals were imported into the UK from 1969 – 1972. Unfortunately, it is estimated that only 1% of these animals survived past their first year. Fortunately for the tortoises, husbandry and care information is now much more readily available. Correct lighting, heating and dietary requirements are understood and, for the most part, met and maintained. This allows the tortoises a more comfortable and extended lifespan with the highest possible level of care.

Coming out of their shell
There are a number of different behaviours that you may see from your pet horsfield tortoise. Some of the most commonly seen are;
• Scratching – this can be a sign of an enclosure that is too small or there is not enough substrate for the tortoise to display natural behaviours.
• Pacing – horsfield tortoises are walkers and can cover vast distances in a day searching for food or a mate. Ample room should be provided to allow the tortoise space to roam and indulge in this natural behaviour.
• Withdrawing into its shell – this is a natural passive defence response; this is exactly what the carapace and plastron evolved for. The tortoise has been startled and is scared. Try to identify what has scared the animal and remove it or allow the tortoise to settle down and come out on its own.
• Biting – anything with a mouth can deliver a bite and tortoises are no different. Biting is either an aspect of breeding behaviour or is being used defensively. Defensive bites only really occur when hands are too close to the beak and the animal feels threatened.
• Banging and butting – horsfield tortoises are notorious for being little bulldozers, running over or through things, uprooting decorations and plants. This is perfectly natural and allows the tortoise to exhibit natural behaviours. Butting is also used by the male when he is pursuing a female.
• Digging – as previously mentioned, horsfield tortoises are diggers. They will dig burrows to brumate, escape harsh weather conditions, maintain their temperature, warm up, cool down or in search of a more humid environment. A level of substrate should be provided to allow for this behaviour and make the animal feel more comfortable.
• Climbing – due to the horsfields natural habitat, they have become proficient climbers. Navigating rocky mountainous terrain, arid scrubland and partly wooded areas. They can and do climb incredibly well.
• Squeaking – this again is mostly seen in breeding animals. The males will mount a female and squeak in the process of copulation.
• Hissing and panting – these two in conjunction with each other are most often associated with feeding. A tortoise will pant and then hiss before taking food into its mouth to taste it and then begin eating. A lone hiss is often the sign of a defensive tortoise, and this will be used to warn the threat away.
• Head bobbing – most often seen in males pursuing females. The male will bob his head repeatedly to attract the female’s attention, but this same behaviour can also be seen between two males attempting to intimidate each other and as a show of dominance.

These are some of the most common behaviours seen in captive horsefield tortoises.

Creating the perfect environment for your tortoise
Indoor enclosure
An appropriate enclosure and life sustaining equipment are the most important part of the husbandry and care of the horsfield tortoise. Without the correct heating, UV lighting or enclosure the tortoise will quickly succumb to environmental stress, a compromised immune system which can lead to diseases and parasites, and potentially death. Here at SAReptiles, we recommend tortoise tables instead of the more traditional vivariums. We believe that the larger amount of ventilation minimises humidity levels and increases air flow. These two factors are incredibly important for the health and well-being of the tortoise. With an open top tortoise table there is a better heat gradient allowing the tortoise to thermoregulate more efficiently. Closed vivariums don’t offer such benefits and the tortoise can quickly succumb to respiratory infections, eye infections and overheating. The life-giving equipment you will need to maintain your tortoise’s indoor enclosure is as follows;
• Light emitting heat source
• Fergusson zone 3 (10-12% desert spec) UV lighting
• Arid style substrate of a minimum depth 4”
• Dry hay bedding
• Decorations and enrichment
• A “bedroom” or an area to escape heat and light
This is the basic equipment that you need to maintain a horsefield tortoise in an indoor enclosure. The placement of the heat source and the UV lighting is crucial in the building of the tortoise’s environment as this will dictate how well the animal can thermoregulate and its exposure to the UV lighting.
As with all reptiles, horsfield tortoises are ectothermic and cannot generate their own metabolic energy, they rely on external heat sources. Horsfields are a diurnal species and are active during the day, in the wild they use the sun as their primary source of heat, occasionally using large flat rocks to absorb residual heat through their plastron. Once the tortoise has reached its optimum temperature it will begin searching for food. As previously stated, horsfield tortoises will roam several miles a day grazing constantly on one small patch of vegetation before moving on to the next. This is why we recommend a light emitting heat source for horsfield tortoises, they naturally look for bright light as a method to warm themselves up. The placement of the basking lamp should be on one side of the enclosure (preferably the opposite side to the bedroom/shaded area) to allow for a temperature gradient. A temperature gradient is created by localising the hotspot and allowing the temperature to drop the further you move away from it. This allows the tortoise to thermoregulate by moving from warmer to cooler parts of the table.
UV lighting is essential for almost all species of reptile, it is particularly important for all captive species of tortoise. UV lighting (of the correct intensity and frequency) aids in the synthesis of vitamin D3. The tortoises shell produces a cholesterol called previtamin D, when the animal is exposed to UVB radiation and heat the previtamin D is isomerised (transformed by a re-arrangement of atoms in the molecule). The result of this isomerisation is vitamin D3. D3 plays an essential role in calcium metabolism by controlling blood calcium levels, allowing the animal to use the calcium in its diet to maintain strong bones, healthy skin, shell, beak and claws. Vitamin D3 also plays vital roles in the tortoises immune and cardiovascular systems, helping to fight off bacterial and parasitical infection and keeping the animal at peak health. The placement of the UV bulb should cover the entirety of the unshaded area of the table (approximately 2/3rds of the total size of the table) for example, a 36” table will require a UV bulb of 24”. Horsfield tortoises enjoy a high percentage of UV radiation measuring between 2.9 – 7.4 on the UVI (ultraviolet index). The distance from the UV light to the top of the tortoise’s shell should be between 3-10”. The shaded area of the table should be devoid of both heat and light so that the tortoise has somewhere to retreat and feel secure.
Substrate choice is important for horsfield tortoises as is the depth of the chosen substrate. We recommend more natural substrates such as ProRep tortoise life or desert life. These are dense particle substrates that produce very little dust but are excellent for digging. These should be used at a depth of at least 4” to allow for natural burrowing behaviours. The deeper parts of the substrate will also allow for pockets of higher humidity that the tortoise can dig down to as they would in the wild. Enrichment such as leaf litter, dried grasses, branches, stones and rocks will also be of a benefit to the tortoise, allowing the animal to trample over and dig under different items in its enclosure.
Outdoor enclosure
A Horsfield tortoise will benefit immensely from a natural outdoor enclosure during the warmer months. On our soggy little island of the United Kingdom, we cannot (as recent history in the pet trade has shown) house any species of tortoise outside all year round. A large outside run will allow the tortoise to roam and feed on grasses and leafy weeds and greens. The run itself should be as large as you can make it. We recommend a size of 6×4’ and upwards. The lower third of the run should be solid wood and anchored into the ground, this gives the tortoise a physical boundary so it will not walk into it constantly risking damaging itself and anchored into the ground so that the tortoise will not be able to move it. A wire covered frame (so allowing for unfiltered sunlight for the tortoise) should be used with a tight-fitting lid. Horsefields are climbers and can scale almost vertically if they are determined enough. A lid will also prevent large birds, cats, dogs and foxes entering the enclosure and possibly predating upon the tortoise. There should be an area of the run that is shaded, so that the tortoise can escape the heat and light if it should choose to. A large shallow water bowl should be provided so the tortoise can bathe and drink when it chooses and enrichment can be used outside as well, rocks, branches, leaf litter and dried grasses to name a few. Horsfields should not be left outside overnight, night-time temperatures on average do not stay high enough in the UK to support these animals and the risk of predation increases during the night. We would like to stress that sunshine does not necessarily mean warmth and the temperature should be closely monitored before the tortoise is placed in the outside enclosure. Humidity and moisture levels should also be taken into consideration before allowing the tortoise access to outside. Excessive humidity and constantly damp conditions can cause bacterial and/or fungal issues that can damage a tortoise’s shell and cause respiratory problems.
The best pet reptile?
Horsfield tortoises have been in the pet trade for more than 50 years, thankfully, husbandry techniques, technology and the welfare of the animals has become priority. This means that a lot more horsefield tortoises are being kept responsibly, given the correct heat and light, experience a rich, natural and varied diet and are having long and healthy lives. Horsfields are more complicated to keep correctly and should not be underestimated when it comes to maintenance. They require a lot of time, effort and attention to maintain in a captive environment. If you wish to purchase a tortoise, you should first research as much as you can about the animal and consider very carefully if you can provide a home and the correct care for the duration of its long life. They can be very enriching as a pet, as we can attest, but they are a lot more trouble than you realise!

Not sure about keeping a Horsefield Tortoise? Contact us and a member of our friendly reptile team will happily answer all of your questions.

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