Galápagos Giant Tortoise: Facts and Where to See It

Galápagos tortoises come in two main shell shapes, and the shape follows the island. Domed tortoises live in the cooler, greener uplands, where grass and leaves grow close to the ground. Saddle-backed tortoises live in dry coastal country, and the front of their shell flares upwards like a saddle, so the neck can stretch high towards the pads of tall prickly pear cactus.

• Domed. The type seen in the Santa Cruz highlands, a rounded shell for grazing at ground level.
• Saddle-backed. A raised front edge that lets the head reach upwards, found where cactus is the main food.
• Built to carry the weight. Small air chambers inside the shell help the thick legs hold up a body of up to 260 kg.

A tortoise moves at about 0.26 km/h (0.16 miles per hour), rests for nearly 16 hours a day and can go up to a year without food or water. That last ability made them a store of fresh meat for passing ships.

On Santa Cruz, adult tortoises migrate. A study by Stephen Blake of the Max Planck Institute for Ornithology and Washington Tapia of the Galápagos National Park fitted 17 adults with GPS loggers and followed them for two years. In June, at the start of the cool dry season, the large adults begin a walk of up to 10 km up the slopes and spend the dry months around 400 metres above sea level, where fog keeps the vegetation growing. When the rains begin, they walk back down to the lowlands, where the plants are then more nutritious. Young tortoises stay in the lowlands all year.

The guide sighting records follow the same rhythm: in the Santa Cruz highlands, wild tortoises are rated Likely from June to December and Possible from January to May, when many are lower down.

Tortoises reach maturity at about 20 to 25 years and mate in the hot season from January to May. The female walks to dry, sandy ground, digs a hole and lays 2 to 16 eggs, which hatch after around 130 days. The temperature of the nest decides the sex: warmer nests produce more females. Females on Santa Cruz stay in the lowlands until they have laid, then follow the males uphill.

Hatchlings face rats, pigs, dogs and fire ants on many islands, so the national park collects eggs and young from wild nests. They grow up in breeding centres on Santa Cruz and Isabela and return to the wild at 4 to 5 years old.

Each species lives on its own island or volcano: Santa Cruz alone has two, and northern and southern Isabela have five between them. Their food is grass, leaves and cactus, and the seeds pass through the gut and grow where the dung lands, which makes the tortoises gardeners of their islands. Darwin's finches hop onto them and pick ticks from the folds of the skin.

In the green highlands of Santa Cruz, tortoises graze in open pasture. At the El Chato reserve a pond is often ringed with tortoises, and sometimes full of them, wallowing in the cool water.

Guide sighting records list giant tortoises at 10 visitor sites on 5 islands. 3 of them are rated Likely, with sightings on most visits: the wild tortoises of the Santa Cruz highlands, the Charles Darwin Station on Santa Cruz and La Galapaguera on San Cristóbal. The other sites are rated Possible or Rare, among them Urbina Bay on Isabela, where wild tortoises appear only occasionally.

The highlands of Santa Cruz are the place to see tortoises living wild. The breeding and rearing centres on Santa Cruz and San Cristóbal show the young ones that will later be released.

Giant tortoises are in Galápagos in all 12 months, and the breeding centres show them at any time of year. The wild tortoises of the Santa Cruz highlands are easiest to find from June to December, after the adults have walked uphill. From January to May many stay lower down, and the guide records rate the highlands Possible for those months. In the next twelve months, 906 departures stop at a site where they are seen.

Yes. Depending on the species, the IUCN lists them as Vulnerable to Critically Endangered; both Santa Cruz species are Critically Endangered. Pirates, whalers and traders took between 100,000 and 200,000 tortoises from the 17th to the 19th century, and introduced pigs, dogs, cats, rats, goats and donkeys still eat eggs and young or compete for food.

Recovery. The Pinta tortoise died out in 2012 with Lonesome George, the last of his kind. On Española, a breeding programme has raised the population from 14 tortoises to more than 1,000, and a tortoise found on Fernandina in 2019 belongs to a species thought extinct for more than a century. Galápagos National Park rules keep visitors at least 2 metres (6 feet) from the animals and on marked trails with a naturalist guide.

1. Counting on a beach landing. Most wild tortoises live inland. A route with a visit to the Santa Cruz highlands decides whether you see them in the wild.
2. Expecting the highlands to be the same all year. From January to May many adults are lower down, and the guide records rate the highlands Possible.
3. Taking a breeding centre for the wild. The centres show young tortoises in pens. Both are worth it, but they are different visits.
4. Getting too close. Park rules set at least 2 metres between visitors and wildlife, even when a tortoise crosses the trail.