Turtles are some of the most adorable sea creatures. With their unique shells, these amazing creatures stand out from other sea and land reptiles. We bet there's a lot you don't know about turtles, and for the turtle-curious, we have put together 21 interesting turtle facts.
Did you know that all tortoises are turtles, but not all turtles are tortoises? Turtles have existed for a very long time, since the age of dinosaurs. Sea turtles have been around since over 100 million years ago1. Some people keep small turtles and tortoises as pets. Read on for more turtle facts.
Related: For more turtle inspiration, check out our compilation of the best turtle quotes from conservationists, turtle fans, and others reflecting on the turtle’s pace of life.
General turtle facts
1. There are over 350 species of turtles
There are about 356 species of turtles in the world4. There are so many different types of turtles. Popular species include hawksbill turtles, leatherback turtles, flatback turtles, loggerheads, red-eared sliders, western painted turtles, and African side-necked turtles, amongst others.
We can find a variety of turtle species widely distributed all over the world. We can find turtles in shallow coastal waters, bays, lagoons, estuaries, and even the ocean and open sea. Turtles live on land and in freshwater and saltwater.
They exist in all continents except Antarctica. Southeastern North America and South Asia have the highest number of native species. Only five species of turtle can be found natively in Europe. You can only find the flatback as a sea turtle in Australian waters.
2. Turtles can’t leave their shell
Turtles are reptiles of the order Testudines. All turtles have their bodies enclosed in bony shells. The top shell is called the carapace, and the bottom is called the plastron. The bony shells develop from their rib and vertebral column. The upper and lower shells join together to form a skeletal box.
A turtle can't leave its shell, ever. The turtle's shell is made of bones and cartilage that are an integral part of its body.
3. Sea turtles can’t retract their head
Some turtles can retract their limbs and head into their shell when facing danger. However, sea turtles cannot retract their heads or flippers into their shells. This inability may have developed because they do not have to protect themselves from predators on water.
Turtle species that can retract their heads are divided into two major groups: the 'side-necked turtles' and the 'hidden neck turtles.’ This categorization is based on the way the head retracts. The hidden neck turtle retracts its head straight back into its shell, while the side-necked turtle folds its neck to one side while retracting it.
4. Turtles have a varied diet
Turtles are primarily omnivores, but some species, like tortoises, are predominantly herbivores. Omnivorous turtles that live in water eat jellyfish, squid, mollusks, and sea vegetation. The green sea turtle eats jellyfish primarily. Tortoises eat only plants or invertebrates and carrion.
Turtles have keratin beaks, which they use to grasp food. Hawksbills have a strong hawk-like beak, which they use to cut through sea sponges, anemones, and coral. Turtles have no teeth, but loggerheads and alligator snapping turtles (also one of the largest freshwater turtles) have powerful jaws that allow them to feed on fish, shellfish, mollusks, and lobsters.
5. Tortoises are a kind of turtles
Tortoises are a species of land turtle that live exclusively on land. They share similar exo-skeletal shells with other turtles but have columnar feet instead of the flipper-like limbs common to turtles. They live in habitats ranging from forests to deserts.
Note that not every turtle that lives on land is a tortoise. The box turtle and wood turtle are not tortoises. Read more in our article exploring the differences between turtles and tortoises.
6. Turtles have a long lifespan
Many turtles face so many threats as hatchlings that just one in a thousand survive into adulthood. But the turtles that survive live very long; they live comfortably up to 50 years or more. In the wild, box turtles live for about 30 years.
Some sea turtles do not reach sexual maturity until they are 50 and typically live for 70 years or more.
7. Turtles can weigh up to a thousand pounds
Turtles vary significantly in size5, ranging up to 2 to 7 feet and weighing from 70 to over 1,500 pounds.
The leatherback sea turtle is the largest sea turtle species. It can weigh up to 2,000 pounds. The largest leatherback ever recorded measured 9 feet and weighed 970kg2. They discovered it on the Welsh coast in 1987.
The largest turtle in history lived more than 100 million years ago. We call it the Archelon; it was 21 feet long.
8. Turtles hold their breath
Turtles don’t have gills, so they need oxygen as humans do. But they hold their breath for an extraordinary length of time. Sea turtles spend up to 4-7 hours sleeping in water, and some turtles even hibernate in water. Turtles can dive long distances, up to 3,000 feet, in search of jellyfish. Turtles come up to the water surface for air between lengthy dives to forage for food.
Turtles can drown even with their amazing breath-holding capacity. Drowning usually occurs when turtles get entangled with fishing gear and cannot come up for air. Since the level of activity a turtle engages in determines how quickly it uses up stored oxygen, it loses oxygen quickly from the stress of trying to untangle itself.
9. Turtles cry
If you ever get the opportunity to observe a sea turtle out of the water, you may observe that tears are pouring out of its eyes. The sea turtle cries not because it is hurt or sad but to get rid of excess salt in the body.
The lacrimal glands of the turtle are located behind the eyes. They excrete a saline solution that is twice as salty as seawater3. These salty tears mix up with water immediately in water, but on land, we can see them. The turtle’s tears keep out sand from its eyes and prevent dehydration while nesting.
10. Green turtles don’t have green shells
One would easily assume that green turtles are so-called because they have green shells, but in actual fact, these turtles have brownish shells and green skin.
The greenish skin color that gives them their name acquires this color due to their primarily vegetarian diet. They eat a lot of seagrass and algae.
11. The leatherback sea turtle travels a lot
Leatherback sea turtles are unique because, unlike other turtles, they don’t have a hard shell. Instead, they possess a leather-like back. They travel a migratory distance of over 10,000 miles a year between their nesting and foraging grounds6.
The leatherback turtle is also a deep-diving marine animal. They can dive to 4,000 feet, far more than most marine animals can dive.
12. June 16 is World Sea Turtle Day
Sea turtles have June 16 set aside as a day where they are honored and celebrated. These beautiful creatures have been a part of the earth’s existence, going back to the age of dinosaurs. They appear in many traditions as symbols of wisdom or trickery.
13. Temperature determines a turtle’s sex
Whether a turtle emerges from the nest as male or female depends solely on the nest's temperature. All the turtle hatchlings will be male if the sandy nest is cool throughout incubation. If the temperature is warm, the nest will produce female hatchlings. When there is a fluctuation of warm and cool temperatures, the turtle offspring will be a mixture of males and females.
Global warming is also affecting turtles. Warmer temperatures mean that fewer male turtles are hatching. This will adversely affect the continued existence of turtles.
14. Turtles love lights
Sea turtles are phototactic; they are attracted to light. It is this attraction that guides them home to the sea. The light that guides them is the big bright moonlight reflecting alluringly on the water.
This attraction is becoming fatal, thanks to humans. Human encroachment on habitats where sea turtles lay eggs introduces artificial lights that confuse turtles.
15. Some turtles practice arribada nesting
The olive ridley and kemp’s ridley turtles display a nesting behavior called the arribada. Arribada is the Spanish word for arrival, and during nesting season, these two species of turtles arrive at the shore in large groups called arribadas. They stay for several hours at a time.
There are many theories as to why the olive ridley and Kemp’s ridley turtles nest together like that. However, the practice reduces the rate at which predators consume their eggs and allows many eggs to become hatchlings.
16. Turtles lay eggs
Turtles are oviparous; that is, they reproduce by laying eggs. Female sea turtles mate at sea and come to land to lay eggs on what we call the nesting ground. They dig holes to lay their eggs, called a clutch, and fertilize them with sperm stored from mating earlier. They dig these holes, which are about 2 feet deep, with their hind flippers. Sea turtles nest at night, but Kemp's ridley turtle is the only turtle that nests during the day.
Female turtles lay multiple clutches per nesting season, laying about 100-125 eggs per nest. The eggs mature within two months, and the sea turtle hatchlings dig out of the nest and go to the sea.
17. Sea turtles are not very social
Apart from the group nesting behavior that some species exhibit, breaking out of the nest in large groups is something turtles do. Once baby turtles break out of their shells, they stimulate others to do the same. This strength in numbers makes it possible for them to climb out of the deep nest and overpower certain predators on their way to the sea.
Turtles do not care much for social life; after hatchlings reach the water, they generally remain solitary until they mate.
Turtles do not have much in the way of maternal nurturing instincts. The female turtle takes care to protect her eggs by camouflaging the nest. But beyond that, they offer no special care for their hatchlings. After nesting, the turtles never return to check on their baby turtles.
18. Turtles take care of the sea bed grasses
Turtles are one of the few animals that eat seagrass. The turtles that graze on seagrasses help to maintain the sea bed. Like regular grass, seagrass needs to be kept short, so it can grow healthily and spread across the sea bed. Seagrass is not just food for turtles and other animals but also a breeding ground for many fish species.
Also, turtles promote vegetation on beaches and dunes. When turtles nest, not every clutch or single egg will hatch. The unhatched eggs and discarded eggshells provide nutrients needed for dune vegetation. As dune vegetation grows, it stabilizes dune structure and prevents beach erosion.
19. Turtles bring tourists
Watching turtles on land and in the deep sea is awe-inspiring and exciting. Turtle-watching is a tourist attraction that brings economic development to many areas. It serves as a source of income for coastal residents.
20. Some people eat turtles and their eggs
Turtle eggs serve as a traditional source of food within local communities. It could be used as meat and leather, amongst others. Turtles and their eggs have long been eaten in many parts of the world, and they continue to be in great demand commercially. In some areas, local populations and entire species have been hunted to extinction.
21. The turtle’s existence is threatened
Turtles face many dangers in their lifetime. While very young, predators like fish, birds, snakes, and humans prey on young turtles. As adults, they are still in danger from human predators. As eggs, hatchlings, or adults, climate change and plastic pollution endanger turtles.
On the dark side, the consumption of these turtles and the dumping of wastes and toxins in water bodies and other environments adaptive to the turtles threaten their existence. Further, poachers catch them to service the pet turtle trade.
Out of the seven species of sea turtles, six are endangered by human activities.
Wrapping up our list of turtle facts
Our list of turtle facts shows you how vital turtles are. These cold-blooded reptiles warm the hearts of many. Many turtle species are critically endangered, and there’s a lot you can do to save turtles. You can save turtles by educating yourself about climate change and plastic pollution.
Related: To further explore the animal kingdom, check out some other animals that start with T.
Top 10 facts about marine turtles. World Wildlife Fund
Information about sea turtles. Sea Turtle Conservancy
Mariluz Parga (2021) Why do sea turtles cry? Submon
George R. Zug. Turtle. Encyclopaedia Britannica
Sea turtles (2019) National Geographic.
10 tremendous turtle facts (2020) National Oceanic and Atmospheric Administration.