Giant tortoises once occurred on all continents, except Antarctica. However, competition with other species, climate change, and the arrival of human beings and their rapid colonization of the earth meant that the giant tortoises, large, tasty, and easy to kill, were quickly hunted to extinction anywhere where people lived. Oceanic islands provided safe refuges until the golden age of sail brought traders and whalers who learned that giant tortoises could live for months with no food or water, and thus provide fresh meat during long voyages. Holds were filled, sailors gorged, and in a few decades the last of the world’s giant tortoises were all but exterminated. By the turn of the 20th century just two groups remained; on Aldabra Atoll in the Seychelles and on the Galapagos Archipelago, 1000km off the west coast of Ecuador.
Galapagos was discovered accidentally in 1535 by the Bishop of Panama, Frey Tomás de Berlanga, when his ship was blown off course on its way to Peru from Panama. The islands were not made famous until over 300 years later, in 1859, when Charles Darwin published his revolutionary hypothesis on the “Origin of Species by Natural Selection”. Darwin’s observations of the various forms of Galapagos tortoises, each found on a different island, were central to the development of his theory.
Galapagos tortoises (Chelonoidis species) are the largest terrestrial reptiles on earth. Like Frey Berlanga, they arrived accidentally by floating on strong ocean currents from the South American mainland after being swept into the sea. Unlike Frey Berlanga, they arrived between 2 and 3 million years ago. A single fertile adult female may have founded the entire Galapagos tortoise lineage. Once a small breeding population was established on one island, subsequent accidents (tortoises falling or being washed into the sea) led to the colonisation of at least 9, possibly 10 islands on the archipelago. When Tomas de Berlanga arrived on Galapagos, some 15 races of tortoises existed; by the time of Darwin’s death only 12 had survived the onslaught of human need and greed. Today, with the death of Lonesome George in 2012, the last of the Pinta Island tortoises, just 10 living species remain for certain, though there is an interesting twist. Genetic evidence collected recently indicates that the very sailors who caused the demise of the giant tortoises, may have inadvertently also saved them! Amazingly, hybrids of Floreana and Pinta tortoises are alive and well on Wolf Volcano in northern Isabela Island.
As direct threats from whalers and buccaneers drew to a close, the surviving Galapagos tortoises faced new dangers from colonization, agriculture, and introduced species including goats, rats, and pigs. In 1959 the Galapagos National Park and Charles Darwin Foundation (CDF) were formed to restore Galapagos as one of the world’s great ecological spectacles, including conserving its best-known species, the giant Galapagos tortoise. Today, thanks to the efforts of these institutions Galapagos tortoises and their environment have a promising future, but multiple threats remain. We hope to assist conservation by providing scientific answers to some of the following questions:
• What are the spatial needs of tortoises?
• How, when, where and why do Galapagos tortoises migrate?
• What factors disrupt movement?
• What habitat resources are critical for survival?
• What are the ecological roles of Galapagos tortoises?
• How are tortoise populations changing over time, particularly in response to management threats and interventions?
Our goal is to assist the Galapagos National Park (GNP) to effectively conserve giant Galapagos tortoises by conducting cutting edge applied science, and developing an inspirational tortoise-based outreach and education programme.
We achieve this through a research programme which uses both traditional techniques, such as direct observations of tortoise behaviour, and high-tech tools including Global Positioning System (GPS) tracking of tortoise movements. We are building partnerships with educators both locally on Galapagos and internationally to translate the results of our research into meaningful products for outreach and education to inspire the next generation of conservation scientists.
Factsheet in English
Ficha técnica en español