Land of Giants

Land of Giants

Perhaps the most well‑known species of the Galápagos Islands is the giant tortoise. In Darwin’s time, some 15 species existed. Today, 11 species remain.

A giant tortoise can weigh as much as a piano, has leathery skin, and a hard, thick shell. As you might expect, each species of giant tortoise is suited for survival on its particular island. For example, those with domed shells can be found living in highlands with fertile pastures. The shape of their shells keeps them from raising their heads very far. So, they needed to find food close to the ground.

Those with saddleback shells—or shells with an upward curve at the front—can more freely stretch their necks. These tortoises can be found on islands with sparse vegetation. Their shell shape gives them flexibility to reach for food that’s higher off the ground, such as bushes and tall cacti.

Galápagos giant tortoise

giant tortoise with saddleback shell

giant tortoise with domed shell

At Risk

Unfortunately, one of the tortoise’s greatest adaptations became the indirect cause of its steady demise. Giant tortoises have the ability to survive for nearly a year without food or water. This made them valuable to sailors and whalers who would collect tortoises from the islands so that they could have fresh meat to eat on long voyages. Tortoises were also exploited for their fat, which was used in lamps. As many as 200,000 tortoises were killed for these purposes for more than two centuries.

Those that survived on the islands were subject to invasive species and predators. Their eggs and hatchlings were often preyed upon by rats, hawks, and pigs. They also had to compete for food with hungry goats.

In 1959, the Galápagos National Park and the Charles Darwin Foundation were established. Soon after, the Tortoise Center on Santa Cruz was created to protect the tortoises.

Tortoises Today

Today, there are two other giant tortoise breeding centers, one on Isabela and the other on San Cristóbal. To slow the loss of giant tortoises, the Tortoise Breeding Centers began raising captive tortoises. Once a tortoise has grown to a size large enough that predators won’t pose a danger, the center introduces them into the wild. By the end of 2017, more than 7,000 young tortoises were released to their island of origin.

Repopulating the islands where tortoises have gone extinct is a priority. This happened on Floreana and Santa Fe in the mid‑1800s and on Pinta Island in 2012, with the death of Lonesome George. Currently, the Santa Cruz highlands and Isabela’s Alcedo Volcano have the largest populations of giant tortoises. Tortoise populations can also be found on Santiago, San Cristóbal, Pinzón, and Española. Their numbers continue to grow.

Who Was Lonesome George?

The Pinta Island tortoise was extinct. That was a fact. No one had seen one on the island since 1906. Until a scientist discovered one by accident in 1971. That tortoise was Lonesome George, and from that moment on, he became one of the rarest creatures in the world. George was moved to the Charles Darwin Research Station on Santa Cruz and lived there for 40 years. He was about 100 years old when he died. The world felt his loss. George had become an important symbol for conservation efforts in the Galápagos Islands and throughout the world.

Life Science

Human Impact, Protecting, the Environment