Radiated Tortoise

Radiated Tortoise, a species belonging to the family of “Testudinidae,” is a native of southern Madagascar. It is recognized by its distinct carapace which is covered by yellow lines emanating from the center of the dark plates on the shell. The lines make a star-like pattern. It is considered to be one of the finest looking tortoises in the world.

Description

Radiated tortoises have the standard tortoise-like body shape. They have a high dome-shaped carapace with a blunt head and large, mammoth-like feet. The head, legs and feet are yellow in color. The upper portion of the head has a black patch which is of variable size.

The carapace is designed with bright yellow lines which emerge from the center of the dark plates in the shell. These intricate lines form a star-like pattern and shine brightly under the influence of light. The carapace scutes are very smooth. The dark color of the shell fades as individual tortoise ages. This makes the shell of the older tortoises lighter in color.

There is a little sexual dimorphism between the males and females. The females have shorter tails compared to males. The scutes are more protruding in case of males. The anal notch present in the plastron on the lower portion of the tail is less noticeable in females than in males.

Picture 1 – Radiated Tortoise
Source – captivebredreptileforums.co.uk

The young ones are off-white and black as they hatch but soon develop the striking coloration that is found in adults. The adults can grow up to a length of 16 inches and weigh almost 35 pounds.

Behavior

Radiated tortoises have some very interesting behavior patterns. Read on to find out what they are:

• Radiated tortoises like to drink a lot of water.
• They are not fond of warmth and will aestivate during hot weather to avoid dehydration.
• These tortoises are diurnal and are active during daytime.
• They are prone to be solitary and mostly live alone.
• They are slow movers.
• While communicating, they use hissing and grunting sounds.
• Capturing these tortoises will lead them to make high-pitched crying sounds. This can last for about an hour after they are captured.

Diet

Radiated tortoises are herbivores and mostly feed on fruits, vegetables, grasses and herbs. Their diet, however, is somewhat different in captivity rather than when they are in the wild.

• Diet in the Wild: These tortoises mostly like to graze and feed on succulent plants, grasses, flowers and fruits. This diet forms almost 90% of their daily dietary requirements. The Opuntia cactus or prickly-pear cactus as they are called is one of their favorite food items. They habitually graze in the same locations thus keeping the local vegetation trimmed and under control. Due to their love for food with low fiber and high protein content, they tend to feed mostly on younger plants.

• Diet in Captivity: Radiated tortoises should be offered a healthy diet of grasses, alfalfa sprouts, ground alfalfa pellets as well as green vegetables like turnip greens and collard greens. They are also known to have chicory, kale, carrots, sweet potatoes, bananas, apples, yam and melons. They also have a special affinity for red foods.

Distribution

These tortoises are mostly found in southern Madagascar. They have also been introduced to places such as Mauritius and Réunion.

Habitat

The Radiated Tortoises mostly like to reside in dry forests and especially in woodlands and Diderae (thorn) forests of southern Madagascar.

Predators

In the wild, they are often attacked by predators like various snakes and birds of prey. However, humans pose as the biggest threat to their survival both through exploitation and habitat destruction.

Adaptations

While attacked by predators, they cannot escape quickly. However, when they are threatened they tend to make a high-pitched noise that scare off their predators. This adaptation helps them to survive from predators.

Reproduction

Male radiated tortoises start mating after they have reached half the size of an adult tortoise, which is almost 12 inches. The females need to be somewhat longer than the males. The males may fight among themselves for the females and roll each other on their backs and ram each other using their shells.

As an initial courtship ritual, the males bob their heads up and down, encircle the females and sniff the females’ legs and cloaca. The male may try to lift the female while copulating so as to prevent the female from moving away. The male mounts the female from behind after she has stopped moving. The male makes grunting and hissing sounds while mating.

Picture 2 – Radiated Tortoise Picture
Source – hoglezoo.org

After mating, the female tortoise will dig a hole 6 to 8 inches deep to form a nest and lay anywhere around 3 to 12 eggs. Incubation period for the eggs may last from 145 to 231 days. The hatchlings measure between 3 to 4 cm in length and they develop their carapace quickly after hatching.

Life Span

Radiated tortoises normally live for around 40 to 50 years but specimens living for more than 100 years have also been found.

As Pets

The Radiated tortoises are considered to be one of the most beautiful tortoises in the world. It is also very rare. Due to such reasons, these tortoises are highly valued as pets. They are costly and hard to get. Since it is considered to be an endangered species, it is now the most protected tortoise in the world. There is an aura of mystery associated with this animal since it comes from Madagascar, an island of strange and exotic birds and animal species. Due to the mystique associated with this animal, people having these tortoises as pets consider themselves lucky to have a great addition to their collection of pets.

Indoor Housing: While keeping them as pets, an indoor accommodation in the form of a turtle table should be provided. A turtle table appears like an upside down bookshelf unit. The size of the table should be increased as the tortoise grows in size. Accommodation for an adult tortoise should have the minimum dimensions of 8 feet by 4 feet. The bottom of the turtle table should be provided with holes to allow sinking of food and water.

A watery area should also be provided for the tortoise. It should be large enough for the tortoise to completely immerse itself if it so wishes. The water area should be shallow enough to prevent drowning.

A small box should be located at the corner of the housing area to provide the tortoise with a cool retreating spot.

Food: Radiated tortoises should be fed cypress mulch that has humidity retention properties. Cypress mulch contributes in developing good skin and scute health.

Lighting Requirements: A 100 Watts lamp should be provided in the tanking environment for aiding artificial basking. The light should be positioned in such a way so as to provide a basking area having a temperature of 32 degree Celsius.

A full spectrum fluorescent light for generating UVB should be provided in the housing area. A UVB source is important for the syntheses of Vitamin D3. Vitamin D3 helps in calcium metabolism.

A mercury vapor bulb can fulfill both the UVB and heat requirements.

Outdoor Housing: An outdoor habitat for a radiated tortoise has got many advantages over an indoor habitat. Outdoor accommodations are especially useful during summer. Some portions of the outdoor home should have a lot of vegetation to provide for a cool relaxing area. These tortoises are also fond of wallowing in muddy areas. Doghouses or hutches can be used as a home for these tortoises. In areas with cold nights, the temperature of the home should be maintained below 16 degrees Celsius with the help of a thermostatic ceramic heater.

Conservation Status

Radiated tortoises are listed as critically endangered by IUCN. Loss of habitat has been the primary reason for their decreased numbers. They have also been overexploited as pets and killed for food. These tortoises are listed in Appendix I of CITES. They are now highly protected and any import or export of these tortoises is strictly prohibited under most conditions. These laws are however largely ignored in Madagascar due to poor economic situations. Although there are no such estimations of the number of tortoises in the wild, their numbers are decreasing at a rapid rate. To curb this tendency, captive breeding programs have been adopted which is now showing some signs of improving their numbers.

Interesting Facts

• An alternate name for this tortoise is Sokake.
• Radiated tortoises make dancing movements in the rain which seemingly looks as an attempt to remove debris from their backs.
• The tortoise named Tu’i Malila lived for 188 years and was the longest living radiated tortoise in recorded history.
• These tortoises are mostly herbivores, although from time to time they will consume small animals as a nutritive supplement to their regular diet.
• Although these tortoises are often hunted for their meat, touching or eating this tortoise is a taboo to the local tribes.
• They are mostly diurnal, although they can also be seen roaming at night.
• The radiated tortoise is not much fond of the cold weather and they cannot stand night temperature falling below 60 degrees Fahrenheit.
• The shell of the tortoise contains nerves and blood vessels and so can feel when it is touched.

Images

Here are some images showing radiated tortoises in all their attractive glory.

Picture 3 – Radiated Tortoise Image
Source – thumbs.dreamstime.com

Picture 4 – Radiated Tortoise Photo
Source – startortoises.net

The radiated tortoises form an essential part of the ecosystem in Madagascar. They are known for their beautiful looks and are often termed as the most beautiful species of tortoises in the world. It is thus important for us to save and cherish this wonder of nature.