Tortoise is a broad name and with a great number of overly general and imprecise definitions. They result in numerous feeding and care mistakes made by inexperienced breeders. These in turn directly affect tortoises’ health and condition. In this post you will find basic information about the maintenance of herbivorous tortoises from subtropical climates.
Habitats of herbivorous tortoises
It is important to realize that tortoises inhabit a variety of environments, characterized by different climatic conditions, land type, vegetation or terrain. This directly affects breeding conditions and diet you must ensure for tortoises kept in your home terrarium.
In a way of simplification, tortoises can be divided into three basic categories:
- tortoises from subtropical climate areas: e.g. Testudo hermanni – Hermann’s tortoise
- tortoises from tropical climate areas: e.g. Centrochelys sulcata – African spurred tortoise
- tortoises from equatorial climates: e.g. Chelonoidis carbonaria – red-footed tortoise
Herbivorous tortoises of subtropical climates
The most popular species found in hobby breeding are those from subtropical climates. One type of such climate is the Mediterranean climate. The most common commercial species from this zone include: Hermann’s tortoise (Testudo hermanni), Russian tortoise (Testudo horsfieldii), Kleinmann’s tortoise (Testudo kleinmanni), Greek tortoise (Testudo graeca) and Marginated tortoise (Testudo marginata). These herbivorous tortoises kept and bred in captivity are still challenging and there is little scientific data available on their nutritional requirements.
According to reports from veterinarians working in zoos, it is important to be aware that the major risk are developmental diseases. The rapid growth of herbivorous tortoises must be controlled and inhibited by reducing the amount of protein, carbohydrates and fats in a diet rich in dietary fiber. Because of the shell special attention must be paid to mineral-vitamin supplementation and an appropriate light source.
How to prepare a terrarium for herbivorous tortoises from subtropical climates?
The terrarium for breeding tortoises should be spacious and well ventilated, so a typical fish aquarium will not work well here. It is better to use a wooden box or a sufficiently large plastic container instead. Transparent walls are not recommended. Tortoises seeing free space outside the terrarium from all sides, will constantly try to get out, which can cause unnecessary stress.
For a young tortoise with a carapace of 5 cm in length the bottom area of the tank should be min. 50 x 50 cm and this is no exaggeration. This dimension should be sufficient for 1.5-2 years of life. For a tortoise with a 10 cm carapace length, the terrarium area should cover min. 80 x 60 cm. Healthy and properly maintained tortoises are active and wandering animals. They require much more space than most reptiles. Such area will provide the space for the animal to move around and allow for appropriate tank arrangement. Remember that tortoises don’t feel good in small spaces.
What substrate to use in a terrarium for tortoises?
As a substrate, you can use clay mixed with finely ground coconut fiber, such as Tropical Bioterra, and very fine sand with rounded grains. When such a substrate dries, it will bind and will not be friable. This will prevent the tortoises’ limbs getting stuck in it, making it easier for them to move around and preventing joint deformity at the same time. It will also make it easier to keep the terrarium clean. In addition, it does not dust but absorbs water and gives it back slowly, maintaining the right degree of moisture. This is important to ensure clean and unobstructed airways in tortoises. Although native to arid areas, tortoise are not desert dwellers. Fot their night shelter they often choose deep burrows with relatively high humidity, usually abandoned by other animals. Therefore, in the cooler part of the terrarium, you can put turf of grass. By watering it, you will constantly supply moisture to the deeper layers of the substrate.
Avoid thicker sand, gravel and small stones as they can be swallowed by tortoises and end with intestinal obstruction. You can use larger, flat stones of sandstone, limestone, dolomite or basalt instead. They will allow tortoises to rub their claws. In addition, if a tortoise tips over and lies on its back, such stones can provide a support point for the limb to help the animal turn back to the correct position. You can also scatter some pine bark and good quality hay on the surface, to make the life and diet of your pet more diverse.
Light and heat source in a terrarium for tortoises
All tortoises require appropriate sources of light and heat to function normally and keep their bodies in good shape. Therefore, this issue must not be neglected under any circumstances. Remember that overheating is also dangerous. Therefore, you need to carefully plan heating and lighting systems. And be extra cautions when installing and monitoring them.
Create a heat spot in one corner of the terrarium. For this purpose, install a heating bulb or radiant heater that will ensure a temperature of around 35°C directly under the radiator. In addition to the heat source, it is also necessary to provide the tortoise with UV radiation in the form of a suitable terrarium compact fluorescent tube or a highly efficient metal halide lamps. Remember that metal halide lamps need a special ignition system, which may affect the final cost of the lighting set. These lamps, however, have the highest efficiency in UV radiation emission. In addition, they give off strong, bright, sun-like light and warmth. But use only specialized terrarium lamp holders. Those intended for everyday use in households may not be resistant to high temperatures and may even cause a fire.
On the opposite side of the terrarium, maintain lower temperature (20-25°C), closer to room temperature. The tortoise will be able to lower its body temperature. The presence of a cooler space will also protect the tortoise from overheating. In this area, you can place the turf dug out together with the grass and herbs that grew on it. If wateref moderately, it will keep fresh in the terrarium for a long time. This will be an excellent variety in the diet of the tortoise, as it can constantly nibble on the plants growing on it.
Ensure that the substrate (apart from turf and a cooler area) is not constantly wet, as this leads to fungal, shell or respiratory infections. Create a hiding place in the cooler zone of the terrarium and make sure that the tortoise can freely enter and turn around in it. To do it, you can use a half-clay pot, a cork oak bark tube or other safe material. Gently wet the hiding place from time to time, never allowing it to dry completely. It will perfectly simulate the specific microclimate of underground burrows, which in nature serve as a hideout for these reptiles.
How to provide turtles with water and food?
Don’t forget about a shallow, very stable water bowl that should be washed and refilled with fresh water every day. It is important that it is a bowl with low edges, because tortoises have limited climbing capabilities, especially the small ones. The bowl must not be placed in the immediate vicinity of a radiant heater, as hot water spoils more quickly and does not provide an opportunity to cool down. Prepare a separate bowl for food. Find out what to feed herbivorous tortoises.
In our climate, which is of the temperate type, it is a good idea to arrange an outdoor paddock for tortoises. They can hang out there from the beginning of June until the end of August. If the weather in a given year allows it, this period can be extended slightly. It all depend on the night temperature, which should not fall below 15°C. The paddock should be properly arranged and equipped with shady places and hiding places, so that the tortoises can take shelter from excessive sun or bad weather.
The walls of the paddock should be dug min. 40 cm into the ground, as tortoises are good diggers and can create subterranean pit and use it to run away. Contrary to popular beliefs, tortoises can also climb quite well, so the height of the barrier should be two lengths of the shell of the largest animal on the paddock. Pay attention to corners, which they also often use to escape. It is also a good idea to protect such paddock against cats, martens or birds with a strong netting. Young tortoises in particular are vulnerable to attacks. Therefore, always make sure that no potential predator will have access to the tortoise.
Remember that access to natural sunlight is the best source of UV radiation, which – combined with proper diet and supplementation – is a guarantee of proper development of tortoises and their excellent skeletal, shell and overall condition.
Herbivorous tortoises hibernation
In the wild, most tortoises from subtropical climates, especially European ones, have a winter rest, that is, they hibernate. This does not apply to North African populations. Tortoises usually spend the winter in underground burrows, often those abandoned by other animals. As they prepare for the season, they slow down their metabolism and become less active. They begin to look for a suitable shelter where they will get their winter “sleep”. At that time they use the minimum amount of energy for their metabolic processes, which they draw on from the previously accumulated stocks. Overwintering is essential to keep the tortoise in excellent condition. At this time the kidneys and liver are relieved. Becasue it is a natural part of turtoises’ life cycle, their organisms are programmed to go into a dormant period of several months once a year. Overwintering is essential if you consider reproduction. Breeding takes place in spring after the animals wake up from hibernation. It is important to remember that only tortoises that are well nourished and in top condition should be allowed to overwinter. Since the topic of winter hibernation is very extensive, I will discuss it in my next post.
de Boer, M., Jansen, L. & Stumpel, J. (2019) Best Practice Guidelines for the Egyptian tortoise (Testudo kleinmanni), EAZA Reptile Taxon Advisory Group
Hatt, J M (2008). Raising giant tortoises. In: Fowler, M E; Miller, R E. Zoo and Wild Animal Medicine Current Therapy Ed. 6. St. Louis, 144-153
Jill Martin Fund, A. C., Highfield, N. (2008) Taking Care of Pet Tortoises, The Tortoise Trust