The giant tortoise is an ancient and iconic species of reptile that specifically characterizes the Galapagos islands. However, thanks to overhunting, shrinking habitats, and the introduction of new species to the islands, the tortoise has remained a threatened species. Now researchers are saying that the species as a whole is finally on its way to a slow-and-steady recovery.

That's at least according to a new study published in the journal PLOS One which details how Galapagos tortoises on the island of Espanola have gained so strong a foothold in their native environment that they no longer require human intervention to maintain a steady population of about 1,000.

And while saving one subspecies of the giant tortoise on one island doesn't sound like much, it's actually an incredible story of recovery and an encouraging accomplishment for conservationists.

That's because while the overall giant tortoise population is only classified as "threatened" by the International Union for Conservation of Nature (IUCN), the Espanola giant Galapagos tortoise (Chelonoidis hoodensis) is currently listed as critically endangered on the IUCN Red List.

"We saved a species from the brink of extinction and now can step back out of the process. The tortoises can care for themselves," study leader James Gibbs at the State University of New York told the Sydney Morning Herald.

This serves as an encouraging reminder that the tortoises can recover back to stable, self-sustaining numbers. A good number of the remaining populations across the island are not doing as well, and are highly dependent on breeding programs and captivity to survive. Only 11 of the original 14 Galapagos populations even lasted long enough to be rescued by the Galapagos National Park breeding program and the Charles Darwin Foundation in 1959. Since then, another subspecies has been lost, with the last Geochelone abingdoni named Lonesome George dying 2012.

The Espanola tortoise once apparently numbered between 5,000 and 10,000. However, with the arrival of people in Galapagos waters, the slow-moving, meter-long saddlebacks quickly dropped to a population of just 15 by the 1960s.

"They were so rare at that point, they couldn't find one another. Many of the females had lichens growing on their backs, and fungi, that indicated they hadn't been mated in a very long time," Gibbs told the BBC.

However, according to the study, the appropriately "slow and steady" efforts to restore natural habitats and encourage breeding has left the Espanola tortoise in a good place. Gibbs and his colleagues believe that humans can step back now and let the animals run their own show.