Syracuse, NY - For 10 weeks this summer, Elizabeth Hunter lived among sea lions, finches and tortoises on the uninhabited island of Pinta, one of the Galapagos Islands.
Hunter, a State University College of Environmental Science and Forestry graduate student, and three field assistants traveled to Pinta Island off the west coast of South America to see if non-native tortoises could help restore the island’s ecosystem.
For centuries, tens of thousands of giant tortoises trampled the woody vegetation and ate the plants on Pinta Island. Then, pirates and whalers hunted them for food, seemingly wiping them out.
The woody plant growth exploded, threatening to crowd out some of the native species that rely on open areas for light, said Hunter, 26, who is from Wisconsin. And now, the growth is so thick that it can be nearly impossible to walk through, she said.
As for the tortoises, three were seen on Pinta Island in 1906. One, nicknamed Lonesome George, was later found in 1972 and taken to the Charles Darwin Research Station on the main island of Santa Cruz.
Researchers have for years tried to find a mate for George — estimated to be 60 to 90 years old — to try to save the tortoise from extinction. So far, not even genetically similar female tortoises have sparked a romance.
Hunter and her team went to the research station where they prepped 39 non-native tortoises to live the rest of their lives on Pinta Island.
The tortoises, all from other islands in the Galapagos, were sterilized because non-native tortoises had never been put on Pinta Island so no one — not even Galapagos National Park officials — knew how many tortoises the island could hold, Hunter explained.
The researchers also strapped Global Positioning System devices to the tortoises that had been living in captivity at the research station.
Once on Pinta Island, 25 park guards carried the tortoises to the middle of the island in an area that provided them with a good habitat.
“We had been thinking the tortoises would be kind of traumatized and hang out in one spot for a couple of weeks after we introduced them to the island,” Hunter said. “They didn’t do that. They started moving long distances right away.”
The tortoises were relatively solitary, but sometimes they’d see another tortoise and stick together for a few days or weeks, Hunter said. And although they were sterile, the male tortoises looked for females and tried to mate.
One type of tortoise — domed-type tortoises — immediately moved to the higher elevations on the island, where they ate leafy green plants.
“When we downloaded the GPS information on the island, we saw that the domed-type tortoises walked in straight lines until they got to where they wanted to go,” Hunter said. “They didn’t wander. When they got to where they wanted to be, then they’d search around for food that they liked.”
Another type — saddleback tortoises — for the most part stayed close to where they were placed on the island. They fed on pads that fell from the arboreal cactus, a prickly pear cactus.
“They loved it,” Hunter said. “It was their favorite food. That was interesting because when in captivity, they were fed non-native plants.”
“It was really fun to observe the tortoises roam around and be free after they spent so much time in captivity,” Hunter said.
Living on the island also was a freeing experience for the researchers.
“For me, it was heaven to be on this place where you don’t have to deal with all the problems with modern society,” Hunter said.
The researchers slept in tents, bathed in the Pacific Ocean and hiked up to 11 hours a day, tracking the tortoises.
In the ocean, Hunter said she had to look out for angry, territorial male sea lions that swam up to her fast. All the other animals Hunter encountered were tame.
“When you’re walking on the island, finches and other birds would follow you around and land on your head and shoulders,” she said. “They were really curious about whatever is new.”
While Hunter said she was surprised the tortoises adapted to their new environment so quickly, she is continuing to analyze all the data collected on the tortoises’ movements and behaviors, as well as the plant community on Pinta Island. Hunter, who returned from the island in August, plans to go back in May to check on the tortoises and see if their presence has changed the plants.
“We’re hoping that the (non-native) tortoises will push back the woody plant invasion, and restore the natural openings,” Hunter said. “From what we’ve initially observed, it looks like the tortoises are doing just that in small areas where they are spending a lot of time.”
In the next few years, the park plans to introduce young tortoises who have not been sterilized on the island.
Hunter said many organizations — including the Galapagos National Park, Charles Darwin Foundation, SUNY-ESF, Galapagos Conservancy and the Houston Zoo — have worked on the project for years. The work was done in a collaboration between the Galapagos National Park and SUNY-ESF, with funding from the Galapagos Conservancy.
Catie O’Toole can be reached at firstname.lastname@example.org or 470-2134.