Turtles
There are many species of turtles living all over the world, both on land and sea. Sea turtles prefer shallow, warm water and mainly live in lagoons or bays though some are found in the deep areas of the oceans and seas. They are not found in very cold places like the Arctic and the Antarctic.
Turtles are one of the oldest reptilian groups in the world. They are older than snakes, crocodiles and alligators and go back over 200 million years, in fact, the era of the dinosaurs. They can live for a long time.
They have a hard shell which protects them from enemies and this outer shell is called a carapace. The inner shell is called the plashtron. The carapace differs in size from one species to another. The carapaces differ in shape. Some are oval in shape while others are more heart shaped. The Leatherback, the Hawksbill, Loggerhead, Green, Olive Ridley, Kemps Ridley and the Flatback are all species of sea turtles.
The largest is the Leatherback sea turtle. It can weigh over a 1,000 pounds and grow to around six feet in length. The smallest are the Olive Ridley and the Kemp’s Ridley species. They grow to around two feet in length and weigh around 100 pounds. A turtle’s shell has 60 interconnected bones.
They have flippers which help them swim well. They also propel them on land but not very well. This makes the sea turtle easy prey to enemies.
Sea turtles generally come to land, actually onto the beaches to lay their eggs. With the help of their back flippers the female turtles dig a hole in the sand and lay their eggs in it. They then cover it with sand. Some turtles leave the eggs to hatch by themselves. When the hatchlings come out they head straight for the ocean but fall prey to predators along the way. Turtle eggs are considered to be a delicacy by some people and therefore people steal them to either eat or sell. Rekawa, in southern Sri Lanka is a popular nesting place for sea turtles.
Sea grass and sea weed, crabs, shrimps and jelly fish are some food varieties that the sea turtles eat. The food they eat depends on their age and the environment they live in. Sometimes, sea turtles look as if they are crying. These tears are from their special glands which allow them to get rid of the extra salt they get living in salt water. Turtles do not need fresh water as they get their water from the food they eat.
Many sea turtles can hold their breath for over 30 minutes and leatherback turtles can dive to a depth of a 1,000 feet. They are also the fastest among the sea turtles and are able to swim at over 20 miles per hour.
Predators, poaching, loss of habitat and getting entangled in fishing gear are some of the factors which endanger sea turtles.
Today, most sea turtle species are endangered and three species are listed as extremely endangered.
Tortoises
Like the turtles, tortoises too have been around for a very long time, in fact, for over 200 million years. This makes them older than other ancient species such as snakes, lizards, crocodiles and alligators. A tortoise named Harriet died at a Zoo in Australia in 2006 and her estimated age was 175 years old. She is supposed to be born around 1830 and is said to have been found by Charles Darwin in the Galapagos Islands, a place famed for tortoises. Tu’i Malila who died in the Tonga islands in 1965 aged 188 was said to have been gifted to the Royal Family of Tonga by Captain James Cook.
Tortises are found everywhere in the world excepting the Antartica. They need a warm climate to breed. A group of tortoises are known as a ‘creep’. But most tortoises are ‘loners’. Tortoises are generally vegetarian but sometimes will eat meat if given or they come across it.
The scales on a tortoise’s outer shell or carapaces are called scutes. They are made of a substance called Keratin which is also found in human finger nails.
An extraordinary fact about tortoises is that they smell with their throats.
The colour of a tortoise’s shell will tell you where they originally came from. Alight shade indicates that they came from a warm country. Tortoises are different from turtles because they live on land and have their toes fused together like in an elephant’s foot.
The Galapagos Islands in the eastern Pacific Ocean are famed for tortoises. They live on around seven of the islands . These tortoises are the world’s largest and oldest tortoises.
(Sources: National Geographic for kids, Kiddle Encyclopaedia for kids, Science facts for kids, Wikipedia, Wikidata)
Sri Lankan Star Tortoise
Sri Lankan star tortoises are on the small to medium sized in range of the star tortoises. When mature, Sri Lankan star tortoises reach the sizes of 7-9″ on average, with a small percentage reaching 10-12″. They are listed as a threatened species and are found mainly in Sri Lanka, India and Pakistan in dry zones and scrub forests up to about 300 metres above sea level. The Sri Lankan star tortoise is considered to be the most beautiful star tortoise in the region.
Star tortoises are herbivores, meaning they are plant eaters. Their food includes mixed grasses, dark greens, weeds, coarse leaves and succulents. Star tortoises like broadleaf weeds better than grasses.
They have a dome shaped hard shell which has beautiful white and yellow markings in the shape of stars. Hence, the name ‘star tortoise’. The spiny and scaly body of the star tortoise is protected by this hard shell. The upper part of the shell is called the ‘carapace’ and the underside is known as the ‘plastron’.
The scaly and spiny body of the tortoise is protected by this hard, outer shell.
Tortoises are considered great pets and are very much in demand in the global pet trade thus endangering them.
The Loggerhead Turtle
These enormous reptiles get their name from their oversized head shaped some what like a big log. Their shells are hard and reddish – brown in colour. Their underbelly or the ‘plastron’ is pale yellow. They are the most common turtle species found in the Mediterranean sea and the coastal waters off the United States of America (USA). They also have four flippers with two or sometimes, three claws each. They are omnivores and mostly eat other marine creatures such as clams, crabs, mussels and sea urchins by crushing and crunching in their powerful jaws.
The life span of a loggerhead turtle in the wild is generally around 50+ years. They weigh around 115 kgs and body length averages around 90 cm.
The IUCN has listed them as vulnerable.
The Leopard Tortoise
The leopard tortoise is found in the savannas of eastern and southern Africa, from Sudan to the southern Cape. It is very attractively marked and are well adapted to semi- arid climate of the African savannahs and do not like damp or cold conditions. They find it difficult to kive in these conditions. The leopard tortoises belong to a family of land tortoises called Testudinae.
Leopard tortoises graze on mixed grasses and they do this during most of their waking hours. Like all other turtles and tortoises they have no ears but can sense vibrations that help them navigate and live in their environment. They have a keen sense of smell which helps them to find food. Again, like all other turtles and tortoises the leopard tortoise has no teeth. They eat by biting and ripping at food with their hard, sharp, beak-like mouths. Leopard tortoises get the water they need by eating the fruit and pads of prickly pear cactus and other succulents that give them water.
They are very active early in the morning and just before the sun goes down, when it is not too hard. They look for shelter during the hottest part of the day and sleep early to avoid the cold
The Leatherback Turtle
Adult leatherback turtles average 1–1.75 metres (3.3–5.7 ft) in shell length, 1.83–2.2 metres (6.0–7.2 ft) in total length and weigh 250 to 700 kilograms (550 to 1,540 lb). The largest ever leatherback found was over 3 metres (9.8 ft) from head to tail and weighed 916 kilograms (2,019 lb). It was found on a beach on the west coast of Wales. Leather back turtles are the fourth largest living reptiles.
These large marine creatures live almost entirely on jellyfish. Due to this, leatherback turtles help control jellyfish populations. They also feed on other soft-bodied organisms, such as tunicates and cephalopods.
Pacific leatherbacks migrate about 9,700 km across the Pacific from their nesting areas in Indonesia to eat California jellyfish. A major cause for Pacific leatherback sea turtles to be endangered is because they mistake floating plastic bags in the ocean for and eat them.