Galápagos Tortoise Sex‍ Linked to Incubation Temperature

Updated June 18, 2025

The sex of a ⁣Galápagos tortoise is not resolute⁢ at ‌fertilization but rather by the temperature at ​which ⁣its egg incubates. According to the Philadelphia Zoo, cooler temperatures yield females, while warmer temperatures produce⁣ males.

specifically, ‌eggs incubated at ⁤or below 82.4​ degrees Fahrenheit tend to hatch as ⁤female tortoises. Conversely, temperatures exceeding 85.1 degrees Fahrenheit typically result in male offspring.

These giant herbivores, ⁤native to the Galápagos Islands off Ecuador, lay up to ⁢20 eggs at a​ time. The⁣ eggs, roughly the size of billiard balls, take⁢ four⁣ to eight months to hatch.

Galápagos tortoises are ⁤known for thier​ impressive size and longevity. Males can reach an average weight​ of ⁣500 pounds, while females typically weigh around ‌250 pounds. In both zoos and their natural habitat, these reptiles can live for 100 to 200 years.