Scientific Facts
| Common Name: | Radiated Tortoise |
| Scientific Name: | Astrochelys Radiata |
| Life Span: | Average of 50 years |
| Weight: | Up to 35 lbs. (16 kg) |
| Length: | Up to 16 inches (41 cm) |
| Habitat: | Dry regions, brush and thorn forests, woodlands |
| Country of Origin: | Southern Madagascar |
Physical Description
A radiated tortoise can grow up to a length of 16 inches (41 cm), with a weight of up to 35 lbs. (16 kg). In terms of appearance, radiated tortoises are considered as one of the most beautiful tortoises in the world. It features a basic bod shape of a tortoise, consisting of the high-domed carapace, elephantine feet, and a blunt head. Their heads, feet, and legs are yellow in color, except for a noticeable size of black patch located on top of their heads.
The carapace of radiated tortoises is marked brilliantly with some yellow lines that radiate from the middle of every dark plate of their shell, thus the name. This pattern of “star” is intricately detailed compared to the normal pattern of other species having the star pattern, including India’s Geochelone elegans.
Other differences include the size, as radiated tortoises are relatively bigger, while the scutes of their carapace are noticeably smoother, not even raised up into a pyramidal, bumpy shape which is common among other similar species. This species has a slight sexual dimorphism. Male radiated tortoises typically have longer tails compared to female tortoises, with notches below their tails that are fairly noticeable.
Reproduction and Development
Male radiated tortoises mate first upon reaching about 12 inches (31 centimeters) in length. The females, on the other hand, may require to be a few inches longer. Males start a noisy process of bobbing their head, smelling the hind legs and cloaca of females. Male tortoises also tend to lift the females up to ensure that they do not move away.
Afterward, the male will mount the female from the back, striking his anal plastron region against the carapace of the female. Grunting and hissing by the male is common during mating. Female radiated tortoises lay from 3 to 12 eggs, usually doing so in a pre-excavated hole with a depth of 6 to 8 inches (15 to 20 centimeters). They depart afterward.
For this species, incubation is quite long, usually lasting between 5 and 8 months. The juvenile tortoises are usually around 1.25 to 1.6 inches (3.2 to 4 cm) upon hatching. They get their high-domed carapace right after hatching.
Native Habitat
The radiated tortoises are endemic to Madagascar, though they only live in the Southern part of the island. They have also been introduced to other places, such as Réunion and Mauritius. They thrive really well in dry forests, particularly thorn forests and woodlands in Southern Madagascar.
Threats and Conservation Status
Radiated tortoises are labeled as critically endangered, being considered as one of the most sought-after tortoises all over the world. The pet trade, as well as human consumption, has eliminated a huge number of radiated tortoises out of the wild, including the population located within their native range in Madagascar.
According to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the radiated tortoise is an Appendix I species, with no legal import or export. Even though this may have helped prevent complete elimination, recovery among wild populations has been relatively slow.
They still appear in the black market trade of pets in most Southeast Asian countries. In Madagascar, human consumption of these tortoises is still a major concern, where tortoise shells are broken open, and the flesh scraped out and left on the sides of roads.
With the efforts of responsible organizations, captive-bred populations among radiated tortoises are doing well, particularly in the United States, as well as in other areas. It is also legal to own one as a pet within the US, though selling and transporting them across state borders require the presentation of a captive-bred wildlife permit from the United States Fish and Wildlife Service. At the same time, captive breeding of this species is also tracked by the North American Studbook.
In March 2016, officials at the Mumbai airport detected 146 tortoises out of a mishandled baggage of a citizen from Nepal. The bag was reported to be owned by a transit passenger, traveling from Madagascar to Kathmandu, leaving the baggage behind. Of the 146 tortoises, 139 were radiated tortoises. Sadly, however, the tortoises were discovered dead with broken shells.
In June 2016, 72 radiated tortoises were reported to be missing from a breeding facility located in Thailand. In April of 2018, over 10,000 radiated tortoises were discovered in residence in Toliara. Out of the complete count, 9,888 live and 180 dead ones were discovered. The live ones were transferred to a private wildlife rehabilitation facility.
Securing a Captive Bred Wildlife Permit
If you are in the United States and are planning to own a radiated tortoise as a pet, some requirements are necessary. As mentioned, a captive-bred wildlife permit is needed. Even though getting one can be quite intimidating to start with, it is relatively easy to secure one.
All you need to do is to print and fill out the registration form and send it to USFWS together with pictures of the intended enclosure that you have prepared for your tortoise. Once the permit is obtained, it is valid for five years, which require annual updating as well.
How to Care for a Radiated Tortoise
In general, radiated tortoises make amazing pets. They have wonderful personalities. One thing to note, however, is that just like other tortoises, radiated tortoises live a long time. Depending on its health, your pet may live with you for up to 60 years or even longer. This factor should be carefully considered before getting one. On the other hand, if you cannot give the commitment of providing long-term care, it is not recommended to get a tortoise.
Radiated tortoises also thrive well in the fresh air and natural sunlight, which is why these pets are commended only by owners who live in locations that allow the tortoises to stay outside in a well-secured enclosure. In a 2 x 3 foot enclosure, up to 4 hatchlings can be kept. Adult tortoises also require a minimum size of around 10 x 15 feet, housing 2 or 3 adults radiated tortoises.
The enclosure can come in different constructions, though some owners prefer constructing the walls of their pets’ enclosures out of wood. This is beneficial as it helps in preserving the tortoise’s shell patterns and colors. If cinderblocks or bricks are used, the shells may become scraped or scratched when they start brushing up against rough surfaces.
Radiated tortoises usually hack up against objects such as the walls of the enclosures. They may also scratch themselves back and forth, which is why it is often recommended for them to do so against wood than cement, rock, or other rough surfaces. The walls of an enclosure need to be at least 1o inches in height for adult tortoises, and around 4 inches in height for hatchlings.
Enclosure Must-Haves
In every enclosure prepared for your tortoise pet, regardless of the size or age of your tortoises, there are items that are considered as must-haves. One is a well-insulated shelter and hide. This allows your pets to avoid the elements of the environment, including wind, rain, and intense heat. Some owners prefer using wood, given that it is a reliable material.
The shelter needs to be built with four walls and a roof, along with an entrance that is easily accessible and can be tightly closed. You would naturally want your pets to easily enter and exit their hide without unnecessarily getting stuck. If you live in a place with frequent rains, you may want to raise the shelter a few inches off the ground. This can be done by attaching legs, or other types of support, along with a ramp that will lead them to the entrance.
The interior part of the hide needs to be insulated well, thus providing a warm and dry environment. This can be done by adding substrates, including cypress mulch and hay. If you are using a heating element, such as a pig blanket, you may no longer need to add bedding. Make sure, however, that there is enough space inside the shelter to allow your pets to escape the heat if necessary. Being exposed to too much heat is dangerous for your tortoises.
Temperature
At daytime, radiated tortoises are comfortable in temperatures ranging within 70 to 95 degrees Fahrenheit. They tend to conserve the heat that they have acquired throughout the entire day, and the heat dissipates slowly during the evening.
If the surrounding temperature suddenly drops below 55 degrees at night, it is very important to provide supplemental heat. Other essential items that should be included in an outdoor enclosure are a food plate, abundant plant life, and a water source. The plants that you will add should be safe for your pets to eat.
Plantlife offers benefits to the enclosure. Aside from being a source of food, live plants will also serve as a shade and a secure place for your pets to hide and feel safe. These hiding areas will also offer additional places for your pets to regulate their body temperatures.
When providing supplemental food, they should be placed on a plate that is clean and easily accessible for your tortoises. This will help in making sure that they do not consume debris or rocks accidentally, as it could be dangerous to them, and could cause intestinal impaction.
Water
Even though radiated tortoises get moisture through the food that they eat, there might not be enough water for them. This is particularly true during the hotter days, which is why a water source should be prepared accordingly. You may want to prepare a simple source, such as a dish or a saucer sunk into the substrate of the enclosure, making it flush along with the ground.
Your pets will drink from the water source, and may even walk in it as well. They may make the water dirty, defecate on it, which means that you need to keep the water clean all the time. You may also want to create a permanent pool by digging a shallow into the ground, coating it using a thin concrete layer. When the concrete dries up, you can start applying a thin layer of water-proof mortar, sealing the pool, making it watertight. This water source can be cleaned up easily. All you need to do is to sweep the basin using a broom, and then filling it up with water.
Behavior in Captivity
Radiated tortoises in captivity are creatures of habit in general. They will stick to a routine daily, which includes eating, basking, drinking, and exploring. By observing and understanding the routine of your tortoise, you can tell whether your pet is suffering from a health problem since this is a common cause for your tortoise to alter its daily routine.
Tortoise care is not that complicated. Similar to other pets; however, it is important to pay attention to detail when it comes to caring for your radiated tortoises. This will ensure that your pets become healthy and happy. Note that hatchlings require more attention than mature ones.
Just like other tortoise species, radiated tortoises live a solitary life. It is not really uncommon to observe a number of them grouped together while grazing. They typically do so in the same area, keeping vegetation trimmed closely. They are also referred to as diurnal, which means that they love warmth, drinking a lot of water whenever possible. They can, however, go for a long period of time without water.
During the hottest time of the year, these tortoises usually burrow in order to escape dehydration and excessive heat. They are also adaptable to the changing of the seasons from dry and arid to heavy monsoon rains when they are observed as enjoying the rain, shaking the waters off. They also screech loudly when they are started as if trying to scare off and intimidate a predator.
Generally speaking, radiated tortoises are peaceful animals, but they can still become highly aggressive towards people whom they perceive a threat.
Hatchling Care
Since hatchlings are so small and are generally kept in housing with temperatures of up to 95 degrees, they may become dehydrated easily. To ensure enough hydration, it is recommended to soak hatchlings once every two days. This can be done by filling a shallow dish with lukewarm water, placing the hatchlings in the dish.
The water level needs to reach just enough below the chin of the hatchlings. The tortoise will then drink the water, with its skin also absorbing the moisture. Most radiated tortoises reserve their resources of water until they locate another source. As such, you do not need to be surprised if your pet defecates while being soaked. In turn, this will make your tortoise hungry. Make sure that you prepare food to give to your pet after soaking.
Note that proper hydration is a very important factor that will ensure smooth shell growth. Together with proper diet, exposure to ultraviolet (UV) light, and enough exercise, your pets will grow healthy.
Food and Diet
Your pet tortoises will surely love it when they are given a wide variety of food options on top of the live plants placed in their enclosure. Their usual diet consists of succulents, grasses, flower blossoms, vegetables, and fruits.
There are also some commercial food options that are available, including the Mazuri Tortoise Diet. This will allow your tortoise to enjoy a varied diet. Be careful, however, when giving them fruits. Too much fruit intake may cause diarrhea, which may, in turn, result in dehydration.
Cuttlebone is also recommended in the enclosure. Sprinkle some supplemental calcium powder occasionally into their greens. Through time, your tortoises will associate their owners with food. This means that they will approach you when it’s already feeding time, filled with anticipation of receiving a treat.
Breeding
Radiated tortoises are observed to be both polygynous (one male mating with multiple females), and polyandrous (one female mating with multiple males). During courtship, the males compete for the females’ attention, trying to roll each other on their backs, ramming one another using the front of their shells. The courtship is usually initiated by the smelling of the hind area of a female and head bobbing among male tortoises.
Radiated tortoises can be sexed accurately the moment they develop a shell of 11 to 12 inches in length. This is about the size when they also attain sexual maturity. It has been observed that radiated tortoises are among the most difficult species to sex visibly. All the usual gender characteristics, including anal and gular scutes, tail length, anal openings, and plastron shape, can all help in determining gender. These traits, however, may still change until they reach 12 inches in length. Thus, it may be challenging to sex them before that, frustrating some owners.
Female radiated tortoises, on the average, are capable of reproducing the moment they reach 12 to 14 inches. Egg-laying, however, has also been documented among turtles as small as 11 inches. Unlike other species of tortoises, radiated tortoises do not hibernate, which means that females can reproduce all year round, depending on their environment in captivity.
In Madagascar, in particular, the start of the breeding season is signaled by the rainy season. This is why a great way to encourage breeding in captivity is to use a misting or sprinkler system in the enclosure. During warmer days, when the sprinklers and misters are operating, it is common to observe mating activities going on.
Usually, male tortoises initiate mating by circling a female tortoise, usually giving her a nudge or two. Then, the male will mount the female tortoise from behind. Similar to other species, the male usually makes a grunting sound during mating.
It is a common observation that most male radiated tortoises are, at times, lazy when showing sexual interest to female tortoises. In these cases, separating males and females for just a few days may work in sparking interest again before reintroducing them again. Also, introducing another male to the enclosure may result in a competition, thus leading to the more dominant male mating with the female.
The usual clutch size is three to six eggs. The production of eggs increases when the tortoises reach 15 to 20 years of age. Another characteristic of this species which may be annoying to breeders is that the females will usually produce a few clutches when they reach maturity first, but slow down, or eventually stop producing eggs for a while, until they become older by a few years.
At times, females urinate on their substrate to soften it or use their hind legs in order to dig a nest measuring around 5 inches in diameter and 6 inches in depth where they can lay their eggs. As you remove eggs from the nest and transferring them to an egg box that contains the incubation medium, make sure that they are oriented in the same position in which they were laid. Making the mistake of turning them may end up in the death of the developing embryos inside. Some breeders bury the eggs to a 3 to 4-inch layer of moist vermiculite as incubation.
In the wild, radiated tortoise eggs often go through diapause, which means that they go through a period of cooling before they start developing. From laying to hatching, this process takes up to 120 days. During the first 30 days, the eggs need to be incubated, increasing temperature along the way. It is usually recommended to keep the eggs incubated at cooler temperatures, and raising the temperature of incubation again to 86 degrees. This helps in tempering the transition in-between temperatures.
Humidity is another important factor that needs to be considered during the incubation process. Having the right humidity level is more crucial a few weeks before and during the actual hatching. A 50% humidity at incubation is the recommended level, with a 75% increase by the time that the eggs hatch around 120 days after being laid.
With the efforts of those who are in favor of captive breeding, the population of radiated tortoises is hoped to continue and thrive even in captive environments, and in nature again.
Where to Get One?
You can get radiated tortoises from a pet store specializing in tortoises. They will require; however, you to present the needed authorization to have one as a pet. You may also get them directly from breeders. They are available in different ages and sizes, from hatchlings to adults.
Interesting Facts about Radiated Tortoises
Here are some interesting facts about radiated tortoises:
- A radiated tortoise that is captured will produce a high-pitched cry, which continues for around an hour.
- They usually “dance” in the rain, trying to remove debris from their backs.
- They have several methods of defending themselves, such as loud screeching sounds, and pulling their head and soft legs inside their shells.
- The oldest recorded radiated tortoise was named Tu’i Malila, living to a ripe, old age of 188 years. Another tortoise named Adwaita is also believed to have been older until the time of death in 2006.
- Even though radiated tortoises are usually hunted for their meat, eating it or even touching it is still considered taboo for some local tribes.
- Radiated tortoises cannot tolerate colder temperatures at night, especially when temperatures go below 60 degrees Fahrenheit.
- These tortoises can feel when you touch their shell, as the shell contains nerves and blood vessels.
FAQ Section
Why are radiated tortoises endangered?
The main reason why radiated tortoises are endangered is because of habitat loss. They are also being poached for food, and even overexploited in the pet trade.
Is it possible to own a radiated tortoise?
In the United States, it is legal to own a radiated tortoise. Selling and transporting them across state borders require presenting a captive-bred wildlife permit. This permit is released by the U.S. Fish and Wildlife Service.
What do radiated tortoises eat?
Radiated tortoises are herbivores. In fact, grazing makes up about 80 to 90 percent of their diet. They usually feed at daytime, eating fruits, grasses, and succulent plants. Their favorite food in the wild is the Opuntia cactus.
Do radiated tortoises like being touched?
In general, tortoises can feel when their shells are being touched. This touch is usually experienced as a different sensation than when their body is being petted. It is also worth noting that tortoises love their necks being petted and scratched.
Do radiated tortoises get lonely?
These tortoises are not likely to get lonely. In fact, they are solitary reptiles. As such, it is recommended to have one tortoise per household only.
