Karmactive Staff
The Philadelphia Zoo recently announced the birth of nine more Western Santa Cruz Galapagos tortoises, bringing the total number of hatchlings from their nearly 100-year-old tortoise pair to 16 this year. The new arrivals mark a significant milestone for both the zoo and global conservation efforts for this critically endangered species.
The nine hatchlings – six males and three females – hatched between May and July 2025. They join seven siblings that hatched earlier this year, all parented by Mommy and Abrazzo, both estimated to be nearly a century old. The births made Mommy the oldest known first-time mother of her species.
“The story of Mommy, Abrazzo and their now 16 babies has captured the imaginations of people around the world,” said Dr. Jo-Elle Mogerman, the zoo’s president and CEO. “It’s made us all think about what legacy means when it comes to conservation and protecting what is precious.”
The breeding success represents years of careful planning. Abrazzo arrived at the Philadelphia Zoo in October 2020 from Riverbanks Zoo in South Carolina based on a breeding recommendation from the Association of Zoos and Aquariums (AZA) Species Survival Plan. Introductions between Mommy and Abrazzo began in 2022. Though Mommy has laid five clutches since 2023, only two produced viable eggs – one in November 2024 and another in January 2025.
The hatchlings significantly boost the managed population of Western Santa Cruz Galapagos tortoises. Before these births, only 44 existed in U.S. zoos. With the addition of these 16 babies, the population has increased by about 36%, with 60 tortoises now in the AZA managed population.
“In less than a year, our animal care team has done what was considered nearly impossible twice,” said Lauren Augustine, the zoo’s director of herpetology. “This success is also not possible without the collaboration of the entire Zoo, including our veterinary, facilities, conservation education and fundraising teams.”
The sex of Galapagos tortoises is determined by incubation temperature. Eggs kept below 82.4°F produce males, while those above 85.1°F produce females. The November 2024 clutch resulted in four females and three males, while the January 2025 clutch produced three females and six males.
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Western Santa Cruz Galapagos tortoises face multiple threats in the wild, including human-wildlife conflict, invasive species, and habitat loss. They are listed as critically endangered by the International Union for Conservation of Nature (IUCN).
The hatchlings are currently splitting their time between their habitat inside the Reptile and Amphibian House, an outdoor habitat near the building, and behind-the-scenes areas. They will remain at the Philadelphia Zoo for at least one year, with potential transfers to other facilities to be determined in fall 2026.
Seven of the tortoises have already been named by animal care staff, including names that honor important figures in herpetology and conservation. The zoo is also running a fundraising campaign giving supporters a chance to name one of the male tortoises. For each $25 donation, participants receive one entry in the naming contest, with proceeds supporting the zoo’s conservation efforts.
Galapagos tortoises are the largest living tortoise species, with males growing up to 500 pounds and females averaging around 250 pounds. Scientists estimate they can live between 100-200 years, making these hatchlings potentially the start of a century-long legacy for conservation.
As Augustine noted, “Now this animal, who’s been in Philadelphia since 1932, will be represented here for, hopefully, another 100 years because her offspring are now part of our collection.”
