December 1, 2017
On the morning of Thursday, November 30, the first eggs of tortoises with partial ancestry of Chelonoidis niger — the tortoise species from Floreana island — began to hatch at the Fausto Llerena Tortoise Center on Santa Cruz Island.
The captive breeding program for Floreana tortoises began in March as part of the Giant Tortoise Restoration Initiative (GTRI), jointly developed by the Galapagos National Park Directorate and Galapagos Conservancy. Since nesting began in the summer, 124 eggs have been collected and placed in incubators.
The program began with 20 breeding adults (12 females and 8 males), most of them transported from Wolf Volcano on the northern end of Isabela Island in November 2015. The offspring from the four breeding groups established this past March, after the genetics of the individual tortoises had been determined, will eventually repopulate Floreana with giant tortoises with partial ancestry of the species of that island — which went extinct approximately 150 years ago.
Park ranger Christian Sevilla, who is responsible for the Conservation and Restoration of Island Ecosystems, reported that egg collection began in mid-July. After weighing and measuring the eggs, they were placed in incubators where they remained for four months until the hatching began. Two-thirds of the eggs were placed in the incubator that maintains a temperature of 85.1° F (29.5° C), which allows for the development of females, and one-third of the eggs went to the incubator with a temperature of 82.4° F (28° C), which produces males — as the sex of giant tortoises is determined by incubation temperature.
These results mark the beginning of what will be a long-term process for the ecological restoration of Floreana Island, as giant tortoises were the only large herbivores and constitute an ecosystem engineer, vital to the island and its native flora and fauna.
Content based on a press release from the Galapagos National Park Directorate, translated with their permission.