Turtles and tortoises are some of the oldest living reptiles, having roamed the earth for more than 200 million years. Many people call tortoises turtles, and that’s not wrong. Tortoises are, in fact, turtles, but not all turtles are tortoises. Both are encased in bony or cartilaginous shells, and both belong to the taxonomic order called Testudines.
Differences Between Turtles and Tortoises
The main difference between turtles and tortoises comes down to where they live. Tortoises are exclusively land dwellers, while turtles spend most of their time in the water, either in oceans or freshwater bodies around the world, only coming to land to lay eggs.
This adaptation to their respective habitats is reflected in their bodies. Turtles have a more streamlined shell—flatter and thinner than a tortoise shell—that helps reduce drag while swimming underwater. Their legs are similar to flippers, with webbed feet that allow them to swim with ease. Tortoises, on the other hand, have a domed shell and thick limbs, which help them navigate their terrestrial habitats, such as the mountains of Santa Cruz in the Galapagos. Tortoises are easily recognizable by their hind-limb anatomy, which is elephantine (or columnar).
There are seven different types of sea turtles: hawksbill, loggerhead, leatherback, olive ridley, green, flatback and Kemp’s ridley. The largest marine turtle is the leatherback, which can grow up to six feet long and weigh 2,000 pounds.
There are 49 different species of tortoises, which vary in size. Similar to turtles, tortoises can grow large, with the giant tortoises of the Galapagos and the Aldabra giant tortoise of the Indian Ocean being among the greatest, featuring shells of up to four feet long and weighing 700 pounds.
Marine turtles are migratory, swimming thousands of miles. Interestingly, they return to the same beach on which they were hatched when they’re ready to lay their own eggs. Tortoises tend to migrate on a smaller scale, moving from the highlands to the coastal lowlands to lay their eggs.
Another major difference between turtles and tortoises is their diet. Tortoises are mainly herbivorous, chomping on cacti, grass, fruit, weeds and other vegetation, while turtles consume everything in their path, including fish, small invertebrates, seaweed or aquatic algae.
Small-shelled reptiles living in freshwaters and brackish waters are called terrapins, and they are often found in local ponds and lakes. Terrapins have sharp claws and a snapping jaw, and they won’t hesitate to bite!
Where to See Sea Turtles and Giant Tortoises
When people think of turtles, the Galapagos Islands often come to mind, and rightfully so. The word “Galapagos” in Spanish means “shape of a saddle,” which a tortoise shell resembles. The islands of the Galapagos, located in the Pacific Ocean about 600 miles from continental Ecuador, are home to Pacific green sea turtles and giant tortoises.
The giant Galapagos tortoise is only found on the enchanted isles. One of the most iconic giant tortoises to ever grace the islands was Lonesome George, who was thought to be the last surviving tortoise from Pinta Island. It was estimated that he lived to be 100 years old. Scientists predict that giant tortoises can live up to 150 years. It’s humbling to think that some of the giant tortoises roaming the islands today lived relatively peaceful lives, through the invention of electricity, the industrial revolution, several world wars and the advent of the Internet. Their ability to sleep for nearly 16 hours per day and bask in the sun grazing on grass probably helps them lead such peaceful lives.
Lonesome George belonged to one of the fourteen subspecies of giant Galapagos tortoises inhabiting the archipelago. He lived at the Charles Darwin Research Station, based in Puerto Ayora, Santa Cruz, from 1971, until his death in 2012. Despite efforts by the Galapagos National Park to save the Pinta subspecies by finding George a mate, it wasn’t a success. Two other subspecies have also become extinct.
The giant tortoise subspecies can be identified by the shape of its shell, a evolutionary distinction caused by their geographic locations on the islands. Those visiting the island of Santa Cruz are likely to see the giant tortoise with the “dome-shaped” shell, which is often found on larger tortoises that feed on grass in lush vegetation. The “saddleback” shell, found on tortoises from Española, makes it easier for the animal’s long neck to emerge and feed on difficult-to-reach vegetation such as cacti on drier islands.
Green sea turtles are highly migratory creatures, making their way from Baja California in Mexico south to Costa Rica, the Galapagos and Peru. They can go as far west as Hawaii and the Marshall Islands. Their carapace (the upper side of the shell) comes in colors ranging from olive to brown, and even black, depending on the location of their habitat. Visitors to the Galapagos Islands can see them on snorkeling excursions.
Those wishing to get up close to these shelled reptiles can choose from a variety of small-group Galapagos trips offered through Natural Habitat Adventures. Our Classic Galapagos trip offers an immersive travel experience in the Galapagos, with a full week aboard a privately chartered yacht carrying just 14 to 16 guests. The expedition is led by highly trained naturalist guides and includes opportunities to swim with sea lions and turtles, spot whales and spend a night at Tortoise Camp, a private camp located in the highlands of Santa Cruz. Here, wild tortoises roam freely across land overlooking the Pacific Ocean and guests can stay in raised canvas tents or even treehouses.
Turtles and Tortoises Under Threat
Nearly all seven sea turtle species are endangered. Climate change, water pollution, habitat loss, fisheries bycatch and human activities such as egg stealing and hunting for skin and food are some of the primary causes for concern when it comes to the potential demise of sea turtles.
Green sea turtles are unable to pull their heads and limbs inside, making them more vulnerable to predators. Their eggs are often in danger of being stolen from the nest by humans and predators. Additionally, since turtle hatchlings move towards moonlight when finding their way to the ocean, light pollution from human establishments veers them off course. Even if a hatchling makes it into the ocean, its chances of survival are one in a thousand, as they are still tiny (only around two inches long) and vulnerable. Green sea turtles benefit from having very few light sources in many of the inhabited Galapagos Islands, where they are relatively safe.
Giant tortoises are threatened because they have historically been exploited as a meat source, a practice that they need protection from even today. They face further threats by introduced species such as dogs and cats that prey on the young, and cattle that competes for vegetation. A tortoise-breeding project at the Charles Darwin Research Station is helping increase the depleted population of these long-living reptiles.
Guests on a Nat Hab Galapagos trip have the opportunity to visit a sustainable farm, Montemar, run by Roberto Plaza. The farm started with the growing of Arabic coffee plants on abandoned pasture land, and a portion of the proceeds from coffee purchases go towards funding the restoration of tortoise ecosystems, as the area serves as an important migration route for these rare creatures. The funds are allocated for research to study giant tortoise behavior, food preferences and resting places and to track these gentle giants to monitor their movements.