This week let’s learn about giant tortoises! What’s the difference between a turtle and a tortoise? The most basic difference is that the turtle lives in water and the tortoise lives on land. And there are some really, really big tortoises in the world!

A Galapagos tortoise:



Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This episode was supposed to be about strange reptiles, with more awesome suggestions from listeners. I was going to include some information about a couple of giant tortoises…but the more I researched, the longer that part of the episode became, until it just took over. So here’s an episode about giant tortoises, and we’ll have the strange reptiles episode in a couple of weeks instead. I’m going to give a shout-out to listeners Leo and Finn, who have been waiting patiently to hear their suggestions. Sorry you’ll have to wait a little bit longer.

The biggest tortoise in the world is the Galapagos Tortoise, which as you probably know, or can guess from the name, lives in the Galapagos Islands off the coast of Ecuador. In fact, the islands were named after the tortoises. Galapago means tortoise in Old Spanish. There are eleven species of Galapagos tortoise alive today, but there used to be 15. The others were mostly eaten to extinction by sailors who would stop by the Galapagos Islands, capture tortoises, and sail away with them to eat later.

The biggest individual Galapagos tortoise ever measured was a male named Goliath. When he died in 2002, Goliath was 4.5 feet long, or 1.36 meters, 2 feet three inches high, or 68.5 cm, and weighed 919 pounds, or 417 kg. He was only 42 years old when he died, but Galapagos tortoises frequently live for more than 150 years. Adult tortoises have no predators except humans. They’re just too big, too heavy, too strong, and have too tough a shell for other predators to bother with.

The Galapagos tortoise eats plants, including grass, leaves, fruit, and even cacti. Its neck is long, which allows it to reach plants that are farther away, since it can’t exactly climb trees. It can survive up to six months without water, getting most of its moisture from the plants it eats, but some tortoises on more arid islands will lick dew from rocks to get moisture. Some of the boulders have been licked by tortoises so much over the centuries that they have deep grooves worn in the surface from turtle tongues.

As I’ve mentioned before in other episodes, sometimes herbivores will eat meat when they can get it. The Galapagos tortoise does this too on occasion. There’s a type of finch on the Galapagos that cleans parasites off the tortoises, and to help the finch reach as much of its skin as possible, the tortoise will stand up straight with its legs extended. The finches hop underneath and clean ticks and other parasites from the tortoise’s legs, neck, and the skin between the carapace, or upper shell, and the plastron, the lower shell. But occasionally a tortoise will suddenly pull its legs into its shell and drop, smashing the finches flat. Then it stands up and eats the squashed birds. This is not cool, tortoise. Those birds are trying to help you.

Galapagos tortoises lay round, hard-shelled eggs. The female digs a hole in the dirt that’s about a foot deep, or 30 cm, and lays about a dozen eggs in it. She covers the eggs with dirt, tamps it down with her plastron, and leaves. When the babies hatch, they have to dig their way out of the hole. This can take weeks, but fortunately the babies still have yolk sacs attached that keep them from starving.

One of the Galapagos tortoise species that went extinct recently was the Pinta Island tortoise. The last known individual was called Lonesome George. He was found in 1971 on Pinta Island and taken to the Charles Darwin Research Station on Santa Cruz Island. Although researchers tried to find more Pinta Island tortoises, even offering $10,000 if someone found a female,