Conservation In Action, The Revival of a Species

During our decades exploring Galápagos, our travellers have made a significant impact on local conservation and sustainability efforts, in part through contributions to the Lindblad Expeditions-National Geographic Fund. One such initiative is the local captive breeding program run by the Galápagos National Park Directorate on Santa Cruz Island. This is the remarkable story of an iconic species that was saved by nurturing one truly exceptional giant tortoise.

Saving a Keystone Species

As the sole megaherbivores in the Galápagos, giant tortoises play a significant role in shaping vegetation throughout the archipelago, scattering a variety of seeds—packaged in fresh fertiliser—across island habitats. A critical keystone species, if the giant tortoise disappeared, the interdependent ecosystems of the Galápagos would soon follow.

This was nearly their fate, after 18th-century buccaneers and whalers plundered an estimated 200,000 tortoises for fresh meat at sea. Early settlers dealt two more destructive blows in the forms of habitat loss and invasive species. When conservation efforts began in the 1960s, only a few thousand giant tortoises remained, including just two males and 12 females of Chelonoidis hoodensis ancestry. They were brought to the Charles Darwin Research Station as a hopeful breeding colony, and researchers began searching zoos around the world for DNA matches.

The Making of a ‘Conservation Hero’

In 1977, they found their tortoise: a male at the San Diego Zoo, hence the name Diego. He became an extremely active contributor—where the “Super” comes in—ultimately fathering some 900 offspring, or about 40 percent of the repopulation efforts. Lindblad Expeditions-National Geographic Galápagos field manager and expedition leader Emma Ridley, who has worked in the Galápagos since 1995, reflected on her encounters with Diego: “Most of the time, you could see him either chasing a female or actually catch him in the act.”

Over five decades, the colony helped to repatriate 2,000 tortoise toddlers to Española Island and reached a state of natural recruitment, meaning enough native-born tortoises made it to reproductive age to sustain the species. In 2020, it was time for Super Diego to join his plentiful progeny. With the research station shut down due to the COVID-19 pandemic, it was an unceremonious journey home. Ridley and her team didn’t even get a chance to say, “adios.”

“We felt a bit bereft,” she says, “and were left to wonder how he would like the wild after spending so long in captivity.”

“We were all a bit teary-eyed on board, all the naturalists looking at the screen,” Ridley recalls. “We got some closure seeing him back in his real habitat… after over a hundred years away from home.”

A Well-Earned Retirement

Nearly two years later, in February 2022, they got their answer when the Good Morning America crew joined a voyage aboard National Geographic Endeavour II as part of their “Extraordinary Earth” series. Equipped with a special drone permit and tracking coordinates provided by the Galápagos Conservancy, the ship sailed to Española Island in search of Diego. After five hours, he was spied sleeping peacefully beneath a prickly pear tree, looking just as he had back at the research station. “We were all a bit teary-eyed on board, all the naturalists looking at the screen,” Ridley recalls. “We got some closure seeing him back in his real habitat… after over a hundred years away from home.”

Learn more about Super Diego on Good Morning America expeditions.com/gmagala

SCIENCE AT SEA: Through a formal agreement with Galápagos National Park Directorate, our expedition ships host researchers, facilitate projects, and assist with the training of young local scientists.