A nearly century-old Galápagos tortoise at the Philadelphia Zoo just achieved something extraordinary – she became a mom for the first time and broke records doing it.
4 Facts That Make This Tortoise Birth Remarkable
- The Age Factor: At 97 years old, “Mommy” is now recognized as the oldest first-time mother of her species.
- The Population Impact: Before these babies hatched, only 44 Western Santa Cruz Giant tortoises lived in US zoos.
- The Genetic Significance: Mommy’s genes weren’t previously part of the breeding population, making her babies incredibly valuable for conservation.
- The Long Wait: She arrived at the Philadelphia Zoo in 1932 – that’s 92 years of visitors who might have seen her before this milestone.
“Mommy arrived at the Zoo in 1932, meaning anyone that has visited the Zoo for the last 92 years has likely seen her,” said Philadelphia Zoo President and CEO Jo-Elle Mogerman. “Philadelphia Zoo’s vision is that those hatchlings will be a part of a thriving population of Galapagos tortoises on our healthy planet 100 years from now.”
A Story of Persistence
Getting to this moment wasn’t easy. Mommy laid three clutches since 2023, but none produced viable eggs. In November 2024, she laid 16 eggs about the size of billiard balls and buried them in sand.
What’s fascinating about these tortoises? The temperature during incubation determines their sex:
- Below 82.4°F = males
- Above 85.1°F = females
The zoo’s reptile team wanted to boost genetic diversity, so they carefully arranged the eggs so half would become males and half females. The first baby tortoise poked its head out on February 27.
Why This Matters for Conservation
The Galápagos islands once had 15 different tortoise species across seven islands. After humans got involved, two species went extinct, and the rest range from critically endangered to vulnerable.
These giant tortoises are the largest of their kind worldwide:
- Males often weigh 500 pounds
- Females typically weigh about half that
Their relaxed lifestyle contributes to their incredible longevity:
- 2 hours daily sunbathing
- 8-9 hours eating or moving slowly
- Typical lifespan of 100-200 years
“This is a monumental achievement for our animal care team that worked diligently to provide the right conditions for Mommy to lay her eggs and for the eggs to incubate and successfully hatch,” said Lauren Augustine, the Philadelphia Zoo’s director of herpetology and birds. “Until now, Mommy’s genes were not represented in the AZA population, making these offspring extremely important in the protection of this species.”
When Can You See Them?
The four baby tortoises will stay under expert care for a few weeks. Visitors can come see the new arrivals starting April 23.
You’ll have at least five years to visit them before they might move to other facilities to continue the conservation breeding program and help create more generations of these amazing animals.
