In the latest in a string of great Galapagos news, saddleback giant tortoises, Chelonoidis ephippium, appear to be recovering on Pinzón Island in the Ecuadorian archipelago for the first time in the past century and a half. Only 100 of these tortoises were left in 1959 by the time the national park was established, but it looks like they’re finally able to stabilize themselves.
“We found ten tiny, newly hatched saddleback tortoises on the island early last month,” Galapagos Conservancy’s Washington Tapia Aguilera, Jeffreys Málaga of Galapagos National Park, and James Gibbs of SUNY in Syracuse write in a Nature correspondence from last week. “There could be many more, because their size and camouflage makes them hard to spot. Our discovery indicates that the giant tortoise is once again able to reproduce on its own in the wild.”
It took 50 years of conservation work to begin undoing the damage caused by rats, whalers, and pirates. This included collecting eggs and raising hatchlings in captivity until they reach a “rat-proof” size after four to five years, as well as rat eradication measures. Poisoned rat bait was delivered from helicopters, the Guardian reports. In a recent survey trip to Pinzón Island, Gibbs and colleagues encountered 300 tortoises, resulting in an overall population estimate of well over 500. He describes the trip in a Galapagos Conservancy blog post.
In a PLOS ONE study published this past fall, Gibbs and colleagues described how 1,000 Chelonoidis hoodensis tortoises are breeding on their own on the isle of Española, where their numbers had dwindled down to just 15 by the 1960s. But sadly, Lonesome George, the last Pinta Island tortoise (Chelonoidis abingdoni), died in 2012 after multiple failed attempts to mate him with females from closely related species. But there's still some hope: Pinta tortoise hybrids were recently discovered on another island, where researchers are hoping to replicate these recent restoration successes.
3