October 24, 2016
So far this year, some 313 tortoise nests on Santa Cruz Island have been protected by Galapagos National Park (GNP) rangers, including the species Chelonoidis porteri (on the western side of the island) and Chelonoidis donfaustoi (on the eastern side).
This work, which began in July, seeks to identify a global positioning system (GPS) location of each nest made by giant tortoises in order to protect them from major predators such as feral pigs by using mesh fences. Rangers also conducted control activities for introduced species such as ants that can penetrate the nests and ruin the eggs.
Rangers are also clearing access trails to nesting sites to facilitate the process of releasing baby tortoises as they hatch during the last week of December. Eggs from the nests of the Cerro Fatal area on the eastern side of the island — where the new species of tortoise named in 2015, Chelonoidis donfaustoi, resides — will be extracted from their nests in mid-November, and will be transferred to the island’s breeding center to complete their incubation process and be begin a captive breeding program.
The giant tortoises of Santa Cruz have a domed carapace, and females lay between 16 and 18 eggs each. Hatching success in their natural state depends on weather conditions present during the season, and can reach up to 10% in an area without predators. In captivity at the GNP, where artificial incubators are utilized, hatching success can be up to 75%.
Thanks to these actions, the Santa Cruz Tortoise Center has repopulated the Galapagos Islands with more than 5,000 giant tortoises that now contribute to the ecological restoration of ecosystems.
Content based on a press release from the Galapagos National Park Directorate, translated with their permission.