The Giant Galapagos Tortoise is
the classic Galapagos Islands animal. They gave the islands
their name after the old Spanish word Galapago for saddle
which the shape of the shell of some varieties resembles. The tortoises
on the islands are all part of the same species, Geochelone nigra,
sometimes called Geochelone elephantophus, they can vary
considerably however and there are 14 recognised varieties. Galapagos
tortoises are found nowhere else in the world other than these islands.
state that they can distinguish the tortoise from different islands;
and that they differ not only in size, but in other characters.
Captain Porter has described those from Charles and from the nearest
island to it, namely Hood Island, as having their shells in front
thick and turned up like a Spanish saddle, whilst the tortoises
from James Island are rounder, blacker, and have a better taste
when cooked." Charles Darwin, The Voyage of the Beagle-
There is only one other species of
giant tortoise found in the world, the Aldabra tortoise which lives
on islands in the Indian Ocean.
Galapagos Giant Tortoises can measure
up to 1.5m (nearly 5ft) long from one end of the shell (carapace)
to the other and weigh up to 250kg (550lbs.). It is not known exactly
how long they can live, but it is thought to be at least 150 years,
their growth is determined directly by the availability of food.
They have rings on the individual segments of the shell (correctly
called scutes) which act like the rings on a tree, years
of rapid growth being wide and poor years being narrow. It is not
possible to use these rings to correctly age an animal as a new
and larger layer is added to the plates each year with the old one
remaining above it, older layers can become rubbed off.
The current population of Giant Tortoises
is estimated at around 15,000, there may have been 200,000 to 300,000
originally before they were taken for food by passing ships in the
18th and 19th centuries. Unfortunately for them, a giant tortoise
made an excellent living larder on a sailing ship far from land.
they were stored upside down and would stay alive for months without
water or food. Fortunately such a fate does not await Galapagos
They have also suffered from predation
on the eggs and young tortoises by feral animals such as pigs and
dogs and by competition for food by large feral goat populations
on some islands.