Scientific name: Chelonoidis nigra
Galapagos tortoises have a large bony shell that is a dull brown colour. Their shells are not solid however they are made up of honeycomb structures that enclose small air chambers. This is important because otherwise the tortoise would not be able to walk with the weight of their shell. The tortoises shell is attached to its ribs, so the turtle can not get out of its shell. Under the dome of the their shell the tortoise has its lungs which means if the tortoise gets turned over the weight of its body could crush its lungs. The tortoise has a characteristic shell pattern on their shell for their life, even though the outer layers of the shell get worn off over time. They have large and stumpy legs, dry scaly skin and hard scales. They have four claws on their back legs and five on their front ones. A tortoise is able to pull its neck, head and forelimbs into its shell for protection from predators.
Galapagos tortoises can be up to 1.8 metres (6 feet) from their head to their tail, and 1.2 to 1.5 metres (4 t0 5 feet) across their shell. The females are generally a bit smaller than the males. Male tortoises can weigh up to about 260 kilograms (573 pounds) and females up to about 136 kilograms (300 pounds).
The life expectancy of the Galapagos tortoise is thought to be over 100 years in the wild, and about 150 years in captivity, although one tortoise had an estimated age of 170 years before it died in an Australian Zoo.
Tortoises are herbivores which means that they eat plants. They eat things like cacti, grasses, leaves, lichens and berries. They can eat an average of 32-36 kilograms (70-80 lb). They get most of their moisture from the sap in the vegetation and dew from the ground, therefore they can spend a lot of time without drinking, and when they get water they can store it in their bladders and the bottom of their neck for long periods of time. They can even go 18 months without having food and water because they can break down their body fat to produce water as a by-product.
The Galapagos tortoises are native to seven of the Galapagos islands west of the Ecuadorian mainland. The shell shapes and sizes of the tortoises vary between populations depending on the islands that they live on. On the islands with humid highlands the tortoises have a dome shaped shell, they have shorted necks and they are larger. On islands with dry lowlands the tortoises have “saddleback” shells (looking a bit like a horse saddle), long necks and they are smaller.
Before conservation efforts started in the 20th century their numbers had declined quite dramatically due to habitat clearance for agriculture, the introduction of non-native animals like pigs, rats and goats and the hunting of the tortoises for their meat and oil. They also have to compete with animals such as cattle and goats for food which often results in food shortages.
Tortoises don’t reach sexual maturity until about 20-25 years in captivity and about 40 years in the wild. They usually mate between about January and June in the rainy season. The female tortoise will then travel up to several kilometres (miles) during July to November to get to nesting areas of dry, sandy coast. The female will then dig a hole about 30cms (12 inches) deep to lay the eggs in. There she will lay between 2 and 16 eggs and then cover them with sand and leave them to hatch in the sun, this process takes between four and eight months. Once the tortoises have hatched they have to dig their way up to the surface which can take about a month. The temperature determines what sex the hatchling will be, if the nest is colder there will be more males, and if it is hotter there will be more females. When they are born the hatchlings are between about 50 – 80 grams and about 6cms long (2.4 inches).
Galapago is one of the Spanish words for tortoise
Tortoises really are a slow animal. They only walk at .26 kilometres an hour (0.16 miles) while humans walk at about 4.5 kilometres an hour (2.8 miles).
The oldest life span on record belongs to an adult tortoise in an Australian zoo that was documented to be at least 171 years old.