Turtles are among the most fascinating and emblematic creatures in the natural world. Belonging to the order Testudines, they are instantly recognisable by their bony shell, a feature shared by no other living reptile in quite the same way.
Turtles first appeared on Earth roughly 200 million years ago and have survived several major ecological crises since. Today they are found across an extraordinary range of habitats, from arid deserts to the open ocean. As grazers, seed dispersers and prey, they play a quiet but important part in keeping many ecosystems in balance.
Physical characteristics of turtles
The shell is what truly sets the turtle apart from every other reptile. It is made up of two main parts: the carapace, the domed upper section that covers the back, and the plastron, the flatter lower section that protects the chest and belly. Together they form a single protective structure that the animal carries for its entire life.
The carapace is built from flattened bones fused together and sheathed in keratin, the very same substance that forms human nails and hair. Its shape varies enormously from one species to the next, ranging from high and rounded to low and streamlined, with edges that may be smooth or finely serrated. The plastron, also bony and keratin-covered, is joined to the carapace by ligaments and the bones of the pelvic girdle.
Beyond protection from predators and injury, the shell provides structural support and even assists breathing, expanding and contracting subtly as the animal inhales and exhales. In some species the plastron is partially hinged, allowing the turtle to seal itself almost completely inside its shell when threatened.
Size, weight and lifespan differ widely between species. The smallest turtles measure only a few centimetres, while the largest exceed a metre in length. Weights span an equally vast range, from under 100 grams to more than 500 kilograms in the leatherback sea turtle.
Longevity is one of the most remarkable traits of the group. Some species live well beyond a century: the giant Galapagos tortoise can reach 150 years in captivity, and the eastern box turtle has been recorded living to 138 years in the wild. This long life owes much to a slow metabolism and the ability to lower the heart rate, conserving energy over decades.
Colour and pattern are equally varied. Some turtles are uniform shades of brown, green or black, while others display intricate stripes, spots and geometric markings that help them blend into their surroundings or signal to one another. Aquatic turtles tend to have flatter, smoother shells that ease movement through water, while hatchlings often show lighter tones that darken and sharpen as they mature.
The main types of turtle
Turtles are commonly grouped by where they live: on land, in fresh water or in the sea. Land tortoises are built for terra firma, with high, domed shells and sturdy, clawed legs that let them dig burrows and cross rough ground. Many are long-lived herbivores, grazing on grasses, leaves, fruit and flowers, with familiar species including Hermann's tortoise and the Russian steppe tortoise.
Freshwater turtles inhabit lakes, ponds, rivers and marshes. Their shells are flatter and smoother, and their webbed feet make them strong swimmers able to remain submerged for long periods by slowing their metabolism. Painted turtles and snapping turtles are well-known examples, often spotted basking on logs before slipping back into the water.
Sea turtles are the great wanderers of the group. There are seven species, among them the green, hawksbill, loggerhead and leatherback. Their flippers and hydrodynamic shells allow them to glide effortlessly through the ocean, feeding on jellyfish, algae and crustaceans, and migrating thousands of kilometres each year to return to the very beaches where they hatched.
Where turtles live
Turtles occupy a striking variety of environments across tropical, subtropical, temperate and even cooler regions. Their habitats stretch from humid rainforests and arid deserts to coastlines and mountain slopes, with each species finely tuned to its own corner of the world.
Land tortoises generally favour warm, dry settings such as deserts, grasslands, woodlands and steppes. Hermann's tortoise, for instance, thrives in the Mediterranean garrigue, preferring warm temperatures and low humidity. Freshwater species settle in lakes, ponds, rivers, marshes and wetlands, some seeking calm shallow water and others tolerating faster currents.
Sea turtles roam oceanic and coastal waters worldwide, their range shaped by species and water temperature. Green turtles favour the warm seas of the tropics, while others venture into temperate and subtropical zones, often associating with seagrass meadows, coral reefs and estuaries that supply both food and shelter.
What turtles eat
Diet depends heavily on species and habitat. Most land tortoises are herbivores, browsing on grasses, leaves, fruit and flowers, though a few supplement this with insects and small invertebrates. Freshwater turtles are typically omnivores, taking plants, fish, crustaceans, molluscs and insects as opportunity allows.
Sea turtles vary too: many graze on algae and seagrass, while the leatherback specialises in jellyfish. Younger turtles often eat a more protein-rich diet to fuel rapid growth, gradually shifting towards plants as they mature. To find food, land tortoises forage slowly across their range, freshwater turtles hunt and graze as they swim, and sea turtles dive in search of their prey.
Turtle behaviour
Movement reflects each turtle's home. Land tortoises plod steadily on four legs and withdraw into the shell when danger looms. Freshwater turtles paddle with their feet and surface to breathe, while sea turtles use their forelimbs as oars and their hind limbs to steer, capable of long dives in search of food or safety.
Some species cover astonishing distances. Green sea turtles may travel across open ocean for months at a time, navigating by the Earth's magnetic field to find their way back to familiar feeding and nesting grounds. This sense of orientation is one of nature's most impressive feats of natural navigation.
Turtles also communicate and form simple social structures. Some produce sounds, others rely on body posture to signal mood or intent. Males may compete for dominance and access to females, and certain species gather to bask together or congregate in large numbers during the breeding season.
How turtles reproduce
Reproduction follows a broadly shared pattern across species. It begins with courtship, as males attract females through visual displays and behaviours such as head-bobbing, sometimes competing with rivals first. Mating follows, after which the female searches for a suitable nesting site.
Land tortoises dig a chamber in the soil with their hind legs, while sea turtles haul themselves ashore to lay on sandy beaches. Clutches range from a few eggs to several hundred, depending on the species. The eggs then incubate for weeks or months, vulnerable to predators and to extremes of temperature, before the hatchlings break free and dig their way to the surface.
From hatching, the life cycle moves slowly through growth, maturity and reproduction. Sexual maturity can take many years to reach, and once attained, turtles may continue breeding for decades. Throughout their long lives they move at their own unhurried pace, a rhythm that has served the group well for millions of years.
Threats facing turtles
Habitat loss is one of the gravest threats to turtle populations worldwide. Turtles depend on specific environments to feed, breed and survive, and the destruction of these spaces can be devastating. Deforestation removes the woodland that land species rely on, road and infrastructure projects fragment ranges, and pollution degrades the water that freshwater and marine turtles need.
Climate change adds further pressure by shifting temperatures and rainfall, even influencing the sex ratio of hatchlings in species whose eggs are temperature-sensitive. Alongside these environmental challenges, illegal collection and trade remain a serious concern, driven by demand for meat, eggs and shell.
Conserving turtles
A wide range of conservation measures helps safeguard turtles for the long term. Protected reserves shield key habitats, regulation limits collection and trade, and the protection of nesting beaches gives the next generation a fighting chance. Public awareness, education and research underpin all of these efforts, building the knowledge needed to act effectively.
Dedicated programmes around the world put these principles into practice. Monitoring teams watch over nesting beaches and guide hatchlings safely to the sea, while habitat restoration projects repair the wetlands and shorelines that turtles call home. In the United Kingdom, organisations such as the Marine Conservation Society work to protect marine wildlife and the coastal waters that visiting turtles depend on. Reducing single-use plastics and supporting reputable wildlife charities are simple ways anyone can help.
The turtle in art and home decor
Few animals carry as much quiet symbolism as the turtle. Across many cultures it stands for patience, longevity, wisdom and steadfast calm, qualities that translate beautifully into the home. A turtle motif brings a sense of grounded serenity to a room, a gentle reminder to slow down and move at one's own pace.
In wall art, turtles work across many styles. A flowing watercolour of a sea turtle suits a coastal or nautical scheme, lending a soft, airy feel to a bathroom or bedroom. A bold, colourful aboriginal-inspired design becomes a striking focal point in a living room or hallway, while a realistic study of a tortoise adds character to a study or reading nook. The natural greens, blues and earthy tones of turtle artwork blend easily with botanical and ocean-themed interiors. To explore more wildlife pieces, browse our animal paintings, or for a coastal mood discover our sea paintings.
