Encountering Giant Tortoises On Santa Cruz Island, Galapagos

Giant Tortoise, Santa Cruz Island, Galapagos

Giant Tortoise (Photo Credit: Annie Baggett)

Santa Cruz, the most populated and commercially developed island in the Galapagos, is also the most visited. Near the international airport some 650 miles west of mainland Ecuador, Santa Cruz is the site of the Charles Darwin Research Station and Galapagos National Park, which lead conservation programs in the islands.

While you might spot other forms of wildlife on Santa Cruz – most notably Galapagos sea lions, frigate birds, blue-footed boobies, marine iguanas and Galapagos crabs – the big draws are the giant tortoises. (The name “Galapagos” itself means “islands of the giant tortoises.”)

Once found in many areas of the world, giant tortoises are now extinct in the wild everywhere but in the Galapagos and the Seychelles. Ten subspecies still survive in the Galapagos (the last of one subspecies, known as Lonesome George because of his reluctance to mate, died a few years ago).

While scientists believe the Galapagos may have once harbored up to 400,000 giant tortoises, there are now about 30,000-50,000 in the wild. That’s up from a low of 20,000 some years ago, thanks to a program to build up the species on the islands (an amorous male named Diego, imported from the San Diego Zoo in 1977, helped spur a tortoise population boom on the Galapagos island of Española).

The vast numbers were depleted by sailors collecting the tortoises for food, and by the introduction of non-endemic rats to the islands, who fed on reptile eggs. Goats also competed with the tortoises for the vegetation they eat.

Time is on Their Side

The slow-moving tortoises, who can weigh more than 500 pounds, need days to get from one area of the island to another, but time is something they have in abundance: They can live to be well over 100 years old, and possibly as long as 200 years. It’s said that Charles Darwin himself (whose 1831 visit to the Galapagos inspired his Theory of Evolution) gave a gift of a giant tortoise after he returned from his voyage on the Beagle – and the tortoise lived until the early part of this century.

Charles Darwin Research Station, Galapagos

Charles Darwin Research Station (Photo Credit: Annie Baggett)

Santa Cruz Island has about 3,500 tortoises, but the viewing areas are the best in the Galapagos. You’re virtually guaranteed to see giant tortoises in captivity in the corrals at the Darwin Research Station, which is located in the largest town in the islands, Puerto Ayora. Lonesome George spent his last decades at the research station, as scientists tried unsuccessfully to pair him up with various females.

Viewing Tortoises in the Wild

To view giant tortoises in the wild, tours lead visitors up to the highlands of Santa Cruz, an often foggy and misty area lush with tropical vegetation and pockmarked with huge lava tunnels. Giant tortoises, mostly dome shell males, migrate from the highlands to the lowlands to mate, a three-to-six-mile journey that may take them two months. Most female tortoises remain in the lowlands to lay their eggs – up to 27 at a time, depending on levels of vegetation and other resources – while the males begin the long migration back to the highlands. Most of their travels involve crossing private farmland, where they can find pond water to cool off in dry season and wash off ticks, but the Ecuadorian national park service mandates that farmers allow visitors to enter their land to view the tortoises.

E.T. and Darth Vader

Getting close-up views of the prehistoric-looking tortoises – whose neck and head served as the face model for E.T. the Extra-Terrestrial in the 1982 film – is easy; the tortoises are simply incapable of scampering off. (The sounds made by the tortoises, who emit a kind of low moaning hiss, are reminiscent of Darth Vader from Star Wars.)

The males, twice as large as the females, “fight” over who gets to mate with the female who suits their fancy, but it’s pretty gentle warfare: the male who raises his head higher is the winner. The two main species on Santa Cruz are the dome shells and the saddlebacks. The latter have higher, longer necks so they can reach the higher vegetation common to the lowlands, while the dome shells – more common in the highlands – can eat the grass there and make do with shorter necks.

It’s yet another example of Darwin’s theory of natural selection – resulting in differing evolution of species in different environments — found throughout the Galapagos in birds, reptiles, and other creatures who inhabit these remarkable, remote islands.