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The Russian tortoise, Horsfield's tortoise or Central Asian tortoise Agrionemys horsfieldii, is a species of tortoise that is a popular pet. It is named after the American naturalist Thomas Horsfield.
The Russian tortoise is a small tortoise species, ranging from about 13 to 25 cm, that is approximately 5-9 inches(13–20 cm for males, 15–25 cm for females). They are sexually dimorphic in that the females grow slightly larger (to accommodate more eggs), while males stay comparatively small. Males tend to have longer tails generally tucked to the side, and females have a short, fat tail. The shape of the vent is also different: males have a slit-shaped vent near the tip of their tail, while females have an asterisk-shaped cloaca. The mating of these tortoises involves the male courting a female through head bobbing, circling, and biting her forelegs. When she submits, he mounts her from behind, making high-pitched squeaking noises during mating. Coloration varies, but the shell is usually a ruddy brown or black, fading to yellow between the scutes, and the body is straw-yellow and brown. They have four toes. They live such a long time (about 50+ years), people who keep them as pets often leave them in their wills. They can learn to recognize humans and some seem to enjoy interaction with their owner.
A popular pet tortoise, Russian tortoises are one of the most readily available tortoise species in the USA. Currently, they are not classified as endangered, unlike most other tortoise species. Although they are small, horsfields tortoises do need extensive outdoor space and indoor habitat where they can dig and climb safely. A healthy animal is curious, eager to eat, and more active than some other tortoise species. They are also very territorial and can be aggressive towards others of their kind, so Russian tortoises should not be kept in a small space with another tortoise. When allowed to burrow into deep soil, Russian tortoises have one of the highest tolerances for temperature extremes. They are one of the few species that can be kept outdoors all year round in Las Vegas, Nevada and other climates where the temperature overnight stays above 10C. In other climates, they can live outdoors safely during the months where night temperatures do not sink below 58 °F. The above factors make Russian tortoises attractive for new tortoise-keepers as well as a fun tortoise for seasoned veterans. Care must be taken to protect Russian tortoises from dogs, opossums, raccoons, rats, and other predators when they are kept outside. Russian tortoises are avid climbers and fantastic diggers, so an outdoor space needs to be built in an escape-proof manner, with corner caps and a foundation. They also need proper shelter, deep shade, and an area where they can warm up. Russian tortoises benefit enormously from natural sunlight, and so every effort should be made to provide at least several hours of safe (safe from predators and from overheating) outdoor time each week during the warm season.
Most pet Russian tortoises are currently imported into the United States. Compared to the number of imported tortoises, captive production of this species is relatively low. You should assume that most adult or sub-adult Russian tortoises for sale are imported. Babies are however available on tortoise forums and some online websites.
Russian tortoise hatchlings measure about 1 inch in carapace length. As they mature, they reach a maximum length of 8 to 10 inches. Females are normally a little larger than males at full size. When females are about 6 inches long, they are large enough to begin producing eggs. A single pet tortoise will however be fine if it is never bred. A healthy tortoise will have a length\weight proportion roughly in line with the McIntyre growth graph. A less scientific method to check if a tortoise is a healthy weight is to lift it by hand - a healthy tortoise feels heavy, like a rock of approximately the same size.
Russian tortoises are almost always imported into the USA as young adults between 4 and 5 inches in carapace length. These tortoises are large enough to handle sub-prime conditions during shipping but small enough to fit many in a fixed-size shipping crate. Russian tortoises larger than about 6 inches long can be difficult to find in pet stores, are however occasionally available second-hand from other keepers. Russian tortoises can live for a century if given proper care. Raised on a lean, high-fiber diet of dark leafy greens, captive-raised animals in low-stress environments have higher life expectancy.
The preferred method for raising Russian tortoises is an outdoor enclosure in a warmer climate. Pens for 1 or 2 adults should be at least 10 feet by 8 feet. Enclosure walls should be set into the ground 7 to 12 inches to prevent the tortoises from digging under the sides, and they should be 12 inches or higher above ground. Installing caps on each of the corners will also help preventing escape, as Russian tortoises are avid climbers. Russian tortoises are burrowers. They tend to dig into corners and against objects. Placing large rocks under the soil in the corners helps prevent tortoises from digging out. In higher or lower temperatures, they attempt to go underground to insulate themselves from the extremes. Building Russian tortoises underground hide boxes that maintain more stable temperatures helps to keep them from burrowing too much in unwanted spots. Provide fresh water at all times in a shallow dish or saucer that is large enough for the tortoise to sit in but small enough it can get in and out safely. Sheltered areas and opportunities to dig down to help to keep the tortoises cool are vital in an outdoor enclosure.
Russian tortoises are sure to try to eat any plant accessible to them in their pens. They prefer wide-leafed, high-fiber plants and weeds. Care should be taken to provide calcium-rich plants, and feeding a wide variety is key to providing the necessary nutrients. Russian tortoises rarely eat grass unless they are out of options. Check all plants in the enclosure to ensure they are safe. A good database of edible plants for tortoises is The Tortoise Table. A printable booklet of some widely available tortoise-safe plants and weeds is here: http://www.thetortoisetable.org.uk/site/files/Edible%20doc%203rd%20edition_2013_condensed.pdf
Russian tortoises may be kept indoors for part of the year, when weather is severe. They can be caged in large plastic bins, stock tanks, small plastic pools or a custom built "tortoise table". The table can be made from any recycled material and lined with a water-proof, escape-proof material. Russian tortoises require at least 24"x48" of floor space in an indoor enclosure PER ANIMAL, but more space is necessary for them to thrive. They will become lethargic and withdrawn in a small space, or will obsessively pace and dig in the corners. Providing an area that is as large and as interesting as possible is key, and will also result in a happy, healthy tortoise that is more interesting to observe.
An indoor table must provide heat and sunlight replacement for a minimum of 12 hours each day. Specialist UVb lighting is essential, and is discussed in more detail below. One to two adults can be kept in an enclosure measuring at least 12 square feet, although as mentioned above, Russian tortoises are very territorial, and should ideally be kept solo, or in gender balanced groups of 3 or more, in appropriate space, to avoid bullying. More space is always better. Provide sidewalls 10 inches or higher above the substrate line. Mesh covering or a coping\overhang will deter the tortoise from climbing out, and can help protect the tortoise from other household pets.
Many different substrates can be used. Additive free topsoil, or a mix of topsoil and coconut coir is recommended. Sand is not a suitable substrate. It used to be recommended, but has in the meantime been shown to accumulate in a tortoise's gut through accidental or purposeful ingestion, and can cause impaction and even death. The proportions of the soil/coir mix can vary with the age of the tortoise. The substrate should be moist in the underlayers, and deep enough for the tortoise to burrow into.
A shallow planting saucer filled with water should be provided at all times to soak in and to drink. To further ensure good hydration, an adult tortoise should be soaked weekly in chin-deep lukewarm water. Babies should be soaked more frequently.
Large, flat rocks can help file down the tortoises’ nails and give them a clean surface for food. Russian tortoises also enjoy climbing, so try to provide an enclosure that gives them that opportunity. Despite what most tortoises are housed in at pet stores, they need much bigger enclosures. They should also have access to an area heated by an overhead light. This spot should be in the 90 °F to 100-degree range at shell height. This allows them to raise their body temperature high enough to digest their food. An accurate temperature reading should be taken at shell height with an infrared thermometer or a probe thermometer. Wall-mounted thermometers are not sufficient for determining the basking temperature. Russian tortoises need options to move away from that basking temperatures into an area of the enclosure that is room temperature (72 °F) to cool off. Like most diurnal, herbivorous reptiles, they need a proper reptile UVB light in their indoor enclosures to help them properly process the calcium in their diets. These tortoises can handle nighttime temperatures into the low 50Fs without a problem, and a healthy Russian tortoises does not require night-time heat in a heated home.
Lighting and Temperature
Russian tortoises living outdoors and allowed to bask, graze, and dig burrows are very capable of taking care of themselves in temperate climates. However, Russian tortoises can handle high temperatures only if they can get deep enough underground where it’s much cooler (70 °F). Keeping any tortoise on an outdoor patio or anything above ground when it’s over 100 °F degrees is too hot for them. Keep in mind that the ground temperature in the sun is much hotter than the air temperature. Russian tortoises are most active when temperatures are between 60 °F and 90 °F. They remain active during the cooler parts of the day in midsummer, or they sleep underground in a burrow. Russian tortoises hibernate underground during the winter if they are allowed some time to dig a burrow before cold temperatures set in. Allowing a tortoise to hibernate outdoors carries some dangers, however, as they may freeze or flood, or be eaten by vermin. Alternatively, they can be hibernated in a fixed-temperature refrigerator or an insulated double box. A pre-hibernation wind-down is to be expected and encouraged,. Most tortoises bed down at various times during the fall and come out of hibernation in mid-February. Post-hibernation, daily baths are recommended. They should also have access to an area heated by an overhead light. This spot should be in the 90 °F- to 100 °F range. Like most diurnal, herbivorous reptiles, they need a artificial UVB light in their indoor enclosures to help them properly process the calcium in their diets. Different lighting/heat/UVB options are commonly available online and in stores, and can be adjusted according to your set-up needs. These tortoises can handle nighttime temperatures into the low 50°Fs without a problem.
Ideally, all healthy horsefields should be hibernated for a minimum of 4–8 weeks each year, varying with age and health. Please research hibernation thoroughly beforehand. When hibernation is not an option. Russian tortoises can be over-wintered in their indoor enclosure with the normal temperature gradient of 68 °F to 100 °F. Keep lights on 12 to 14 hours a day, and turn off all light and heat sources at night. If the tortoise is kept awake during the winter, soaking should be continued weekly, and food should be offered daily.
Russian tortoises are enthusiastic eaters, and the destruction they wreak on the plants in most outdoor enclosures is proof of this. Planting tortoise-safe seed mixes in designated areas and letting the tortoise graze freely is the most natural way to feed a tortoise. There are many weeds, shrubs, and garden plants that are safe for tortoises and can be planted in a useful and attractive manner in a tortoise's enclosure. Towards the end of the warm season, if the plants are grazed down, it may become necessary to provide a pile of widely varied edible plants each morning.
In a captive indoor environment, restrict feeding to one serving of a healthy variety each morning. The serving should be the amount to cover the carapace. A horsefield given the opportunity will browse to supplement any shortfall.
Russian tortoises prefer broadleaf weeds and eagerly eat almost any leafy greens offered to them. Regularly use tortoise-safe organic weeds, flowers and herbs. Choose high-fiber, low protein plants. Avoid force-grown sources and any food that might have pesticide or preservative residues. Avoid plants that are high in oxalic acid, as these can prevent calcium from absorbing in the totoise's body. If wild-grown weeds and greens are not available, you can supplement with store-bought greens such as kale, collared greens, turnip greens, mustard greens, and any of the darker lettuce types. Be sure always to wash grocery store greens thoroughly, as some of the chemicals they are sprayed with to prolong freshness can bind vitamin A in the tortoise's body, causing vitamin deficiencies. Variety is the key, a selection of 5 or six healthy leaves and flowers each day is optimum.
Vegetables should only be fed very rarely, e.g. a small piece of carrot or pumpkin once monthly or less. Fruit should be avoided altogether, as the high sugar content can cause parasite blooms and other issues in the Russian tortoise's gut. Animal protein should never be fed to a Russian tortoise, as it can cause kidney failure. High starch foods such as corn and potatoes should not be fed, either, as the starch is broken down into sugar, and will cause similar problems to fruit, in addition to causing obesity.
For their size, these tortoises have a large appetite. A rough guideline for a healthy length\weight ratio is the McIntyre chart of development.
It is wise to plant many different types of safe, leafy weeds in their outdoor enclosures . It might also be useful to partition off parts of the enclosure to allow plants to recover, and rotate the tortoises’ access to the separate areas. Grasses, clovers and various other safe plants can be planted throughout the enclosure. If given full access to all available space, they will almost surely eat the plants down to nothing by midsummer. Metal baskets can be installed over top some of the plants using landscaping staples to prevent plants from being grazed down so far it would kill them.
Even when feeding a wide variety of weeds, greens, and flowers, tortoises need access to calcium. This can be provided in the form of cuttlefish bone (available online, as well as in the bird section of pet stores), or limestone. A healthy tortoise will help itself to these. Sometimes it is necessary to sprinkle calcium onto a tortoise's food. When feeding grocery store greens during the winter, it is additionally recommended to provide nutrients and vitamins by sprinkling "TNT" (dried ground-up tortoise-safe weeds) onto the tortoise's food.
Water and Hydration
Russian tortoises need water dishes in their enclosures at all times. Many prefer shallow, low-sided dishes that are glazed to make cleaning easy. A Pyrex pie dish, sunken into the substrate and surrounded by river rock, works well as well. Cleaning needs to be done daily, as most tortoises tend to soak in their dishes and will often defecate in them. It is important to avoid water dishes with steep, high sides, as tortoises are prone to flipping over the edge of such dishes and landing upside-down in their water, in which case they can easily drown.
Soaking is also an important component of hydration. Many tortoises will self-soak in their water dishes as mentioned above, but supplemental soaks should be provided periodically. A newly acquired tortoise, or a tortoise that is in poor health should be soaked more often. Soaks can be provided in a plastic bin or in a sink. Please be sure that the tortoise can't climb out of the soaking bin. The water should be comfortably warm to the touch and the water level should come up to the seam between the top and bottom portions of the shell. If the tortoise seems distressed when placed in the water, it may be too warm or too cold. Try adjusting the temperature until you find what your tortoise seems most comfortable with. Soaks should be supervised, and last 10–20 minutes, and the water should be changed intermittently if the tortoise soils it.
Babies and juveniles tend to dry out much more quickly than larger, more mature tortoises. Baby Russian Tortoises should be soaked in shallow water up to three times a week (daily when they are very small), for 10–15 minutes, whether they’re housed outdoors or indoors. Babies should also be misted several times each day to help their shell to stay well hydrated for smooth, healthy growth.
For best results, purchase an alert, active Russian tortoise with bright, clean eyes, a healthy proportion of length to weight and walking comfortably. Buy one from a reputable source that will guarantee at least a live arrival. These tortoises can suffer from most common reptile health problems, but parasites and respiratory infections are probably the most common. Although one of the more hardy tortoise species, wild-caught Russian tortoises usually have internal parasites. These parasites are not a huge burden on the animals in the wild, but when tortoises are confined to a small area and they endure the additional stresses of importation, the parasites can build up their numbers to levels potentially deadly to the tortoise. Taking a fresh fecal sample to a reptile veterinarian can get you some idea of the types of parasites present, their numbers and the drugs needed to treat them. Russian tortoises can also be prone to respiratory infections if they are kept in cool or wet enclosures. They need to be able to dry out, particularly if temperatures are low. When vet attention is necessary, it is vitally important to find a veterinarian who is familiar with the specific needs and illnesses of Russian tortoises, not just turtles in general.
Handling and Temperament
Contrary to what many sellers tell customers, tortoises generally should not be handled with any regularity. They are easily stressed when overhandled, and children tend to drop them when spooked. These stress factors can lead to a decline in a tortoise’s activity levels and health. Adult Russian tortoises are generally more resistant to handling, but all tortoises should be handled carefully. Avoid pinning them down or restricting them. Allow them to carry on with their intended ways.
This species is traditionally placed in Testudo. Due to distinctly different morphological characteristics, the monotypic genus Agrionemys was proposed for it in 1966. Today, Agrionemys horsfieldii is currently being accepted. DNA sequence analysis generally concurs, but not too robustly so. Some sources also list three separate subspecies of Russian tortoise, but they are not widely accepted by taxonomists:
- T. h. horsfieldii (Gray, 1844) – Afghanistan/Pakistan and southern Central Asia
- T. h. kazachstanica Chkhikvadze, 1988 – Kazakhstan/Karakalpakhstan
- T. h. rustamovi Chkhikvadze, Amiranschwili & Atajew, 1990 – southwestern Turkmenistan
- Fritz Uwe; Peter Havaš (2007). "Checklist of Chelonians of the World". Vertebrate Zoology 57 (2): 301–302. ISSN 18640-5755. Archived from the original on 2010-12-17. Retrieved 29 May 2012.
- Khozatsky & Mlynarski (1966)
- e.g. Fritz et al. (2005)
- da Nóbrega Alves, Rômulo Romeu; da Silva Vieira; Washington Luiz & Gomes Santana, Gindomar (2008): Reptiles used in traditional folk medicine: conservation implications. Biodiversity and Conservation 17(8): 2037–2049. doi:10.1007/s10531-007-9305-0 (HTML abstract, PDF first page)
- Fritz, Uwe; Kiroký, Pavel; Kami, Hajigholi & Wink, Michael (2005): Environmentally caused dwarfism or a valid species - Is Testudo weissingeri Bour, 1996 a distinct evolutionary lineage? New evidence from mitochondrial and nuclear genomic markers. Molecular Phylogenetics and Evolution 37: 389–401. doi:10.1016/j.ympev.2005.03.007
- Khozatsky, L.I. & Mlynarski, M. (1966): Agrionemys - nouveau genre de tortues terrestres (Testudinidae). Bulletin de l'Académie Polonaise des Sciences II - Série des Sciences Biologiques 2: 123-125.
- Tortoise & Freshwater Turtle Specialist Group (TFTSG) (1996). Testudo horsfieldii. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Listed as Vulnerable (VU A2d v2.3)
- Alderton, D.: Turtles and Tortoises of the World. New York, New York: Facts on File, 1988.
- Ernst, C. H. and Barbour, R. W.: Turtles of the World. Washington D.C.: Smithsonian Institution Press, 1989.
- Highfield, A. C.: Keeping and Breeding Tortoises in Captivity. Avon, England: R & A Publishing, 1990.
- Obst, F. J.: Turtles, Tortoises and Terrapins. St. Martin's Press, New York, 1988.
- Pritchard, P. C. H.: Encyclopedia of Turtles. Neptune City, New Jersey: T.F.H. Publications. 1979.
- Pursall, B.: Mediterranean Tortoises. Neptune City, New Jersey: T.F.H. Publications, 1994.
- Wahlquist, H.: Horsfield's tortoise, Agrionemys horsfieldii. Tortuga Gazette 27(6): 1-3, June 1991.