Appearance : Shape like a saddle, very narrow, compressed, and slightly upturned anteriorly, and wider and lower posteriorly with a rounded margin long neck.Body weight : Males larger than females males weigh 272–317Kg, females 136–181Kg.For quite a long time a single living individual of an 11th subspecies was kept for his safety on the Charles Darwin Research Station on Santa Cruz Island and nicknamed "Lonesome George" Of all 15 different subspecies, which lived originally on the islands, only 10 survive in the wild. One of the most striking animals on the Galapagos Islands is the giant dark tortoise.We anticipate arduous but rewarding times ahead for giant tortoise conservation biologists. Adding them to breeding programs will boost the genetic diversity in the released individuals and calls for a new expedition soon to come. Its appeal is further increased by the fact that our expedition found that many more tortoises with genes from Floreana and Pinta still wander on the slopes of the Volcano Wolf. The repatriated Española population, all derived from 15 captive breeders, now seems well-established.īringing back the Floreana and Pinta species from extinction, something inconceivable not long ago, is now a possibility. The reintroduction of over 1,500 captive-born offspring of the species once found on Española Island is another success story. However, giant Galápagos tortoises can bounce back from major demographic crashes and respond well to reintroduction programs.įor instance, the Volcano Alcedo tortoise population, arguably the largest in the Galápagos, is derived from a single female lineage thought to have survived a catastrophic volcano eruption in pre-historical times. This is a logical concern for reintroduction programs that rely on a small number of captive breeders. Wouldn’t low genetic diversity hinder the long-term persistence of reintroduced populations? These long-lived large herbivores act as “ecosystem engineers”, altering the habitat they live in to the benefit of other species. Reintroduction of these tortoises to the islands where they evolved, together with large-scale habitat restoration efforts, is essential for the restoration of the island ecosystems. Giant tortoises relocated by our expedition from the Volcano Wolf, Isabela Island, to the captive breeding program of the Galápagos National Park, Santa Cruz Island. We airlifted 32 of them to the ship and then to the captive breeding facility of the Galápagos National Park on the island of Santa Cruz. Our teams discovered more than 1,300 tortoises, including nearly 200 that potentially have mixed ancestry from Floreana or Pinta. The precious tortoise would then be moved into the net and airlifted to the ship, which was anchored in Banks Bay. When one of the target tortoises was found, we would contact our mother ship by radio and clear the vegetation of the volcano slopes to make room for the cargo net of our expedition’s helicopter. Added to this ordeal were the frequent encounters with wasps, the equatorial heat, and an El Niño induced six-day period of non-stop rain. The daily mission included patrolling large areas of unstable razor-sharp lava fields and of spiny thick vegetation across Volcano Wolf, the tallest of the Galápagos. Our team of park rangers, scientists, and veterinarians from 10 countries were divided in nine groups of three to four people each. It was ambitious, logistically complex, and very strenuous. Our recent expedition was aimed at finding the animals with a high proportion of ancestors from Floreana or Pinta. ![]() These hybrids include animals whose parents represent purebred individuals of the two extinct species. Many of these tortoises made it to shore and eventually mated with the native Volcano Wolf species, producing hybrids that still maintain the distinctive saddleback shell found in the species from Floreana and Pinta. These animals were collected from lower altitudes islands (Floreana and Pinta) during centuries of exploitation by whalers and pirates, who made the archipelago a regular stop-off for their crews to stock up on these handy living larders. ![]() Old logbooks from the whaling industry indicate that, in order to lighten the burden of their ships, whalers and pirates dropped large numbers of tortoises in Banks Bay, near Volcano Wolf. ![]() It is likely that people have been moving tortoises around the islands. DNA analyses revealed an astonishingly large number of tortoises with mixed genetic ancestry in this sample: 89 with DNA from Floreana and 17 with DNA from Pinta. These exciting discoveries led to an expedition on Volcano Wolf in 2008, where we tagged and sampled over 1,600 tortoises. Volcano Wolf – the highest point of the Galápagos Islands.
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