Pinta Island Tortoises

Giant tortoises are thought to have numbered in the tens of thousands before pirates and whalers began removing them for food. As a result of the over-exploitation in past centuries, tortoises were believed to be extinct on Pinta during much of the past century.  The discovery of a tortoise called Lonesome George on Pinta in 1971 surprised scientists and park managers alike. George was transported to the Tortoise Center on Santa Cruz Island in the spring of 1972 to ensure his safety. While park rangers, scientists and the thousands of tourists who have visited George hope that one day a mate will be discovered - on Pinta, in a zoo, or a private collection - no female Pinta tortoise has been found.

 

In addition to the removal of giant tortoises, which are known to play an important role as ecosystem engineers through movement patterns, herbivory, and seed dispersal, Pinta also suffered large-scale degradation by introduced goats. Three goats released onto Pinta in 1959 eventually resulted in a population of more than 40,000 animals, which destroyed much of the island’s native vegetation. Goats were eradicated from the island in 2003, after which, the vegetation recovered rapidly. However, full and balanced island restoration requires the presence of Galapagos giant tortoises, the natural ecosystem engineers of the Archipelago.

 

While ongoing genetics studies have yet to determine the best species to repopulate the island, it wass important that tortoises be released onto Pinta as soon as possible.   The decision was made to use the hybrid tortoises held in corrals of the GNP on Santa Cruz and Floreana for this purpose.  These tortoises are the offspring of tortoises of unknown origin held in captivity during the early years of the GNP.  Given that one of the main goals of the GNP is to conserve the ecological integrity and biodiversity of the island ecosystems, release of hybrid tortoises into the wild is unacceptable.  Therefore, these tortoises were destined to spend their entire lives—as much as 150 years or more--in captivity.  By sterilizing these tortoises, they were fine to be released into the wild on Pinta, where they will contribute to the restoration of the island’s ecosystem.

The Houston zoos, Dr. Joe Flanagan, along with other veterinarians from the United States worked with the GNP to sterilize the tortoises in November 2009. Since that time, the tortoises have been held in quarantine in a corral separate from all other captive tortoises.  During the last two months, the corral was examined regularly to remove any seeds. Their health was monitored and their feces was also inspected to determine if they had consumed any seeds. It was essential to ensure that the tortoises do not introduce any plant species to the nearly pristine island.  The tortoises were also fitted with satellite and telemetry tags so that scientists can monitor their movements on Pinta.

 

In May 2010, 39 tortoises were released into the wilds of Pinta Island.  They were carried to a mid elevation that provided good tortoise habitat.  This is the first time that tortoises have inhabited the island since the removal of Lonesome George, in 1972. The return of tortoises to Pinta was carried out by a team consisting of the Houston zoo’s Dr Joe Flannegan, park rangers, herpetologists, botanists, and veterinarians, from the Galapagos National Park, Galapagos Conservancy, and the State University of New York at Syracuse. SUNY students have been monitoring the movements, habitat use, and activity of the tortoises since the release.

Dr. Joe Flanagan describing the preparation for the journey to Pinta: 

“Any equipment or supplies going to the outer, unpopulated islands is inspected for seeds and insects, sprayed with insecticide, and then placed into a freezer for 3 days to kill off anything that may have been missed.  The goal is to avoid spreading any plant or animal life from one island to the next, so that each island stays as close to its pristine state as possible.  Everything that goes to the island goes through the quarantine process.  All the food that the students will use in the next 2.5 months, all camping gear, all clothes, everything.

After getting our gear into quarantine, we had a meeting in the Park conference room.  All the park rangers (Guardaparques) who will be going were there to get a briefing on the project.  This is a “big” project, so people were brought in from offices on all the other populated islands (Floreana, San Cristobal, Isabela) as well as from here on Santa Cruz Island.”