Giant tortoises that were once driven to the brink of extinction on a tiny Galápagos island have made an amazing comeback, a new study reveals.
The tortoise population on the island of Española dwindled to just 15 animals in the 1960s, because of damage to their habitat caused by feral goats. Then, about 40 years ago, captive-bred tortoises were released on the island, and now there are about 1,000 of them living and breeding in the wild.
"It's one of the greatest conservation success stories," said James Gibbs, a conservation biologist at the SUNY College of Environmental Science and Forestry in Syracuse, New York. Gibbs led the study published today (Oct. 28) in the journal PLOS ONE. [See Images of a Giant Galapagos Tortoise]Giant tortoises used to be found all over the world, but now, in the wild, they're found only in a few places, including the Galápagos Islands, the Seychelles and the Mascarenes. Whalers hunted the tortoises on Española for food. Fishermen later brought goats to the island in the late 1800s, devastating the native ecosystem and the .
The giant tortoises of Galapagos are among the most famous of the unique fauna of the Islands. While giant tortoises once thrived on most of the continents of the world, the Galapagos tortoises now represent one of the remaining two groups of giant tortoises in the entire world — the other group living on Aldabra Atoll in the Indian Ocean. The Galapagos Islands were named for their giant tortoises; the old Spanish word galapago meant saddle, a term early explorers used for the tortoises due to the shape of their shells.
The closest living relative of the Galapagos giant tortoise is the small Chaco tortoise from South America, although it is not a direct ancestor. Scientists believe the first tortoises arrived to Galapagos 2–3 million years ago by drifting 600 miles from the South American coast on vegetation rafts or on their own. They were already large animals before arriving in Galapagos. Colonizing the eastern-most islands of Española and San Cristóbal first, they then dispersed throughout the archipelago, eventually establishing at least 14 separate populations on ten of the largest Galapagos Islands.
The giant tortoise
THE GIANT TORTOISE POPULATION
GIANT TORTOISE HABITAT :
There are many subspecies of giant tortoises that are found on different islands and have different appearances. Those that live on the larger islands where there is more rain have “dome” shaped shells, while those that live in drier conditions are smaller tortoises and have a “saddleback” shell.
