February 25, 2015
The Galapagos National Park Directorate reported that 159 giant tortoises hatched from the most recent nesting season at the Arnaldo Tupiza Giant Tortoise Breeding Center on Isabela Island. The species of tortoise hatchlings are from Cerro Azul volcano (Chelonoidis guntheri) and Sierra Negra volcano (Chelonoidis vicina).
Between May and September 2014, park rangers reviewed the tortoise corrals daily to locate nests and eventually collected eggs from 27 nests. Each egg is immediately marked with an “X” at the top to indicate its position in the nest, as well as the egg number, the nest number, and the number of the female that laid the nest. Then they are transferred to the incubation room to begin the process.
For incubation, the eggs are placed in one of two incubators with the “X” facing up to ensure they remain in the same position as in the nest. Seventy percent of the eggs are placed at a temperature of 85.1°F (29.5°C), which favors the production of females, and the other 30% are placed at 82.4°F (28°C) to produce males. Producing more females is important to ensure a more rapid population growth once they are returned to the wild. The eggs remain under the watchful eye of park rangers at the Center for up to 120 days.
Once the tortoises have hatched, the hatchlings are placed in a dark box for 30 days to give time for any remaining yolk sac to be completely absorbed. This period in the dark box replicates the weeks to a month that the hatchlings remain in their underground nest in the wild, before digging an exit hole and emerging.
At the end of the 30 days, the young tortoises are removed from the dark box and transferred to hatchling corrals outdoors, where they are provided with constant care to ensure normal development. Each tortoise is regularly measured and weighed, and the data is recorded to provide an assessment of its growth over time.
Tortoises spend approximately six years at the Breeding Center, after which they are ready to be returned to their natural habitat. Conditions at the center are similar to what the tortoises will encounter in the wild, but by providing them with a head-start, they are better able to survive eventual seasonal shortages of water and food — conditions they may find in the wild.
Currently, the Arnaldo Tupiza Giant Tortoise Breeding Center is home to 1,066 tortoises, which will eventually be repatriated to their place of origin.
Translated with permission from the Galapagos National Park Directorate. Please contact Galapagos Conservancy with inquiries.