Marginated Tortoise Information and Care
T. marginata is hardy, and its small to medium adult size (12 to 15 inches) is manageable for most enthusiasts.
The marginated tortoise (Testudo marginata) is a beautiful species of tortoise that occurs primarily in the southern parts of Greece and Italy, with a few isolated populations on islands in those areas. Its range overlaps with that of the Hermann’s tortoise (T. hermanni) in some areas, but wild specimens of the two are not known to hybridize to any major extent (unlike in captivity, where marginated tortoises have been known to hybridize with various other species, including Hermann’s, Russian [T. horsfieldii] and Greek [T. graeca] tortoises).
Marginated tortoises are quite prolific in captivity and captive-bred babies are commonly available in the U.S. They are also produced in large numbers in Europe.
Adult marginated tortoises are recognized most easily by the intense flaring of the rear of their shells, somewhat resembling a skirt. Juvenile shell coloration is contrasting black and pearly white; the intensity of this coloration fades over time, sometimes to a nearly universal dark gray. The skin of babies and adults is primarily black, sometimes with pearly white highlights on top of their heads.
The species’ wild habitat is mostly arid, and marginated tortoises can be found at elevations up to 5,000 feet, and in some very cold areas. The dark shell color helps individuals to warm up in the sun during the morning hours, and they will retreat to shade and shelter during the hottest parts of the day.
Marginated Tortoises Indoors
Marginated tortoises are quite prolific in captivity and captive-bred babies are commonly available in the U.S. They are also produced in large numbers in Europe, and occasionally 4-inch imports are shipped to the U.S. In our experience, these imports have generally done well, compared to other imported tortoises that often struggle after importation.
A first tortoise for many keepers, T. marginata is hardy, and its small to medium adult size (12 to 15 inches) is manageable for most enthusiasts. In an indoor setting, we start babies in low-sided plastic tubs measuring about 3 square feet, minimum (smaller enclosures would not allow proper temperature gradients and room to explore). We start them on coco coir or peat moss, sometimes with a handful of cypress mulch or grass/hay placed on the top of it, or in certain areas. The substrate should be at least 2 inches deep to allow for burrowing and some microclimates; we also keep it moist to maintain some humidity in the enclosure.
A few hiding areas are provided, using items such as ceramic reptile caves; magnolia leaves; flat rocks that are stacked, leaving a tight spot underneath; or similar cage furniture (make sure anything you use, especially if you’re stacking rocks, can’t fall and crush a tortoise). Marginated tortoises like tight hiding places, so half-log hides don’t work as well as smaller, tighter hides.
As young tortoises grow, they can be moved to thicker substrates such as cypress mulch if they are kept indoors. We never use sand for indoor tortoises because it sticks to their food and can irritate eyeballs. Sand/dirt in their wild habitat is very hard packed, and the tortoises aren’t eating directly from the substrate like they often end up doing in captivity (we offer food on a slate tile or plastic feeding tray).
Marginated tortoises that are kept indoors require intense lighting to grow normally and remain healthy and active. Our favorite lights for marginateds are 100-watt Zoo Med Powersun mercury vapor bulbs, which provide heat, light, UVA and UVB all in a single bulb. Position one to maintain a temperature directly beneath the bulb of 95 to 100 degrees Fahrenheit. Temps should taper down to room temperature in the other parts of the enclosure.
We have also raised marginated tortoises successfully with strip UVB lights, such as Reptisun 10.0 bulbs, though these will need a secondary heat source, such as a spot bulb or ceramic heat emitter. (There has been mixed results with the coil-type UVB bulbs, and many people have blamed them for eye issues and overall problems with baby tortoises, so we don’t use or recommend them.)
Marginated tortoises don’t need a heat source at night under normal conditions; they will be fine at 65 to 70 degrees during the night. If humidity is artificially high (above 60 percent), I would keep them above 80 degrees at all times, as cool and humid can be a bad combination that causes respiratory issues. A day/night cycle is good for tortoises; we generally run lights 12 to 14 hours per day.
Keeping Marginated Tortoises Outdoors
Once juvenile marginated tortoises reach about 4 inches in length, they are very much capable of living outside, even in relatively harsh conditions. We much prefer outdoor housing because it allows our tortoises more space, requires less maintenance, and you can plant many foods and seeds that will provide a nonstop food source. Adult tortoises kept in a well-planned outdoor enclosure in most climates become essentially zero maintenance to their keepers, and they much prefer the fresh air! Shallow water dishes can be topped off with drip systems and only cleaned out as needed.
We have raised marginated tortoises outdoors here in Las Vegas from essentially 1 month of age. In addition to plantings that provide an ongoing food source and a small dripper that keeps a quarter of an inch of water in a flat dish, small sprinklers keep things cool in the hottest months, and shade cover is provided overhead. It’s true the tortoises have grown slower under these outdoor conditions than they would have if they were spoiled indoors, mostly because they are on a lean diet, but marginateds are strong, hardy tortoises, and given the right conditions and options, they can handle it.
The substrate in our outdoor enclosures is mostly natural dirt. We try to get all the rocks out that seem to “grow” here in Las Vegas (as tortoises dig around, rocks will keep emerging). We have constructed walls using 2 x 6s, 2 x 12s and concrete blocks. We sink the walls down 6 inches or more, and we also cap the corners with an overhang to prevent any tortoises from climbing out; particularly when a few “stack up” in the corners, they can help each other try and climb out. Walls should extend 12 to 18 inches above the ground.
The larger you can make the enclosure, the better. Our adult marginated enclosures are 15 by 25 feet, which can handle up to about a dozen adults pretty well. Try and plan for the sun exposure and the different seasons. We use trees in the enclosures that drop leaves during the winter, so the ground gets a little more sun during the cooler months, and then the leaves come back to provide summer shade. Mesquite and mulberry trees are over most of our enclosures, with many smaller bushes in the bare areas. The tallest bushes and trees are on the west and central end of the enclosures to help shade the overall area during the summer afternoons. The eastern side is kept more open to let in summer sun and get the tortoises warmed up in the morning. Try and plan ahead to account for tree growth, too; make sure that sunny areas will still be available in future years as the trees grow, particularly in cooler climates.
Planting an outdoor tortoise enclosure is fun. We have made the mistake of buying plants online that weren’t necessarily great for our climate, and then we fought to keep them alive in the heat and the cold. Make it easy on yourself: find non-toxic, tortoise-friendly plants that will do well in your area, and just run with those. We end up using a lot of sage, clump grasses, desert trees and cactus, all of which can be munched on by the tortoises—if the wind breaks off a branch, the tortoises clean up most of that mess.
Hibernating Marginated Tortoises
For hide areas, dense vegetation can be provided; the tortoises will carve their own hideouts into it. We build wooden boxes with small doors that allow the tortoises to enter but keep winter drafts out. Most tortoises will hibernate within these boxes. During the fall, once the tortoises aren’t moving around much—they’re usually in the hide boxes at this point—we will cover them with straw or cypress mulch to help insulate them a little better from the cold-snap nights. The marginated tortoise hibernates in the wild, after all, and, if housed outdoors, it will hibernate in captivity in areas that experience temperatures that are at or below freezing during the winter.
Although the marginated tortoise is one of the most cold-tolerant tortoises, care should be taken to not allow hibernating tortoises to fall below a 33-degree body temperature. If you are concerned about this, you can monitor their actual temperature by placing a temperature probe against them as they hibernate and monitor it during the winter.
In some cases when outdoor temps became too extreme, we have boxed hibernating tortoises in simple cardboard boxes packed with straw and kept them in a spare refrigerator set to about 38 degrees. Once it was warming up outside, we buried them loosely in the ground and covered them with straw. A few weeks later, they were up and active and never skipped a beat.
If outdoor tortoises in very cold climates are going to be artificially hibernated for safety (in a fridge, etc.), leave them outside until they go down naturally, generally when nighttime lows are nearing freezing. At that point, they should have transitioned their bodies and emptied their digestive systems to prepare for hibernation.
Marginated Tortoise Diet
We generally don’t give our marginated tortoises any fruit at all, but almost anything leafy, green or veggie is fair game. It’s really all about variety. We like to use commercial diets such as Mazuri LS tortoise food and Zoo Med grassland (or Gourmet) tortoise foods. These commercial diets contain calcium/D3 and multivitamins which can eliminate the guesswork from your supplementation routine if they are used several times a week. We mix them with other leafy green foods.
Spring mix is a big part of our baby tortoise diet, and we move them on to more roughage as they grow. Our previously mentioned mulberry trees are a great food source, as are many of the desert-type plants we harvest, including sage, globe mallow and prickly pear cactus. Tough foods are good for tortoises, so don’t feel like you need to chop everything into a mush. It’s good for them to have to fight for a bite every now and then, so we leave most foods in their natural raw form.
Are Marginated Tortoises Good In Groups?
Marginated tortoises should be housed only with other marginateds to prevent hybridization. Tortoises raised alone will be increasingly difficult to place into a group or with another tortoise. Tortoises raised in a group will generally get along in a group, and for this reason, we don’t house any tortoises of any species singly.
There are rare occasions where particular tortoises won’t stop pestering others—those, unfortunately, are best housed alone. Otherwise, minor bumping and seasonal fighting shouldn’t be interpreted as a problem. Once a pecking order has been established, such altercations don’t usually become a problem. All of our marginateds and similar species are housed in groups and have very few aggression problems.
Hydrating Marginated Tortoises
Hydration is hugely important when raising baby tortoises. We firmly believe that the biggest killer of baby tortoises is dehydration, whether they aren’t getting enough physical water, or they aren’t kept with a humid microclimate. Heat and dryness together can kill a baby tortoise within hours (this is what can kill a tortoise that gets flipped over—death from overheating, not just from being upside-down).
We keep our baby tortoises of all species on moistened substrate, and all have access to hide boxes maintained with extremely high humidity of more than 80 percent. That said, they always have the option to leave this microclimate, too. In our opinion, the need to provide this microclimate need is the least understood part of tortoise-keeping, and leads to many problems and tortoise deaths.
We soak all baby tortoises in a quarter of an inch of warm water for 10 to 20 minutes almost every day. Juveniles and adults are able to maintain the moisture in their bodies much more effectively, so soaking them is much less critical. We don’t generally keep standing water in the enclosures with baby tortoises because multiple times in the past we have had babies flip over and drown in even a half-inch of water. We have since stopped trying to make that work and just soak them outside the enclosure, where you can easily “force hydrate” them.
As mentioned at the beginning of this article, the marginated tortoise is a great beginner species, but experts love them, as well. Their tolerance for cold and heat makes keeping them very easy in many climates. Their mid size is easy to manage in space-limited areas, and their friendly nature cements their ranking as one of the most popular pet tortoises.
Tyler Stewart is a tortoise keeper/breeder in Las Vegas, Nevada. He and his wife, Sarah, operate Tortoise Supply, an online retailer of tortoises and tortoise-specific supplies. See their site at TortoiseSupply.com.