Mommy the Western Santa Cruz Galápagos tortoise. (Philadelphia Zoo)
A rare Western Santa Cruz Galápagos tortoise who is estimated to be 97 has become the oldest known first-time mother of her species, according to officials at Philadelphia Zoo.
Mommy, who has lived most of her life at the Pennsylvania institution, and Abrazzo, a roughly 96-year-old of the same reptilian stripe, are the new parents to four hatchlings. The newborns bumped the population of Western Santa Cruz Galápagos tortoises in U.S. facilities to 48. In addition to the family of six, Philadelphia Zoo also has Little Girl, who was born at a Bermuda facility in 1940 and moved north in 1956.
The offspring, the first of their kind for the 150-year-old zoo, are a major boon for the future of the critically endangered species. The zoo will debut the currently nameless babies — the staff differentiates them by a dab of nontoxic nail polish on their shells — on April 23. Their introduction to the public will coincide with the 93rd anniversary of Mommy’s arrival at the zoo. They will reside at the popular Philly attraction for at least five years.
Because of their young age and diminutive size, they will live in a protected habitat in the Reptile and Amphibian House, separate from the hulking adults, who can weigh up to 500 pounds.
“They will not be in yard yet because they’re far too small,” said Rachel Metz, the zoo’s vice president of animal well-being and conservation. “The yard is obviously designed for 300- or 400-pound animals, not half-a-pound animals.”
Mommy (her given name, not just her job title) is also a critical member of the Association of Zoos and Aquariums’ Species Survival Plan, a program dedicated to protecting endangered species and maintaining a genetically diverse population through breeding and conservation projects in human care and the wild.
“With their ages and the fact that Mommy is so genetically valuable being a wild animal, this is such a huge success and accomplishment,” said Lauren Augustine, the zoo’s director of herpetology and birds.
Neither the zoo nor the tortoises rushed the mating. Mommy arrived in Philadelphia in 1932, straight from the wilds of the Galápagos. She had had flings with other species, but Abrazzo, whose records go back to a Texas zoo in 1929, was her first Western Santa Cruz.
Specialists, not Cupid, orchestrated the coupling.
“It’s a very fancy matchmaking service that involves a team of geneticists, population biologists, animal-care and husbandry specialists and veterinarians,” Metz said. “They look at the genetic makeup of each individual and the representation of those specific genetics.”
In 2020, the zoo received Abrazzo from the Riverbanks Zoo and Garden in South Carolina. The staff introduced the two in 2022. Sparks didn’t immediately fly.
“At first, it was clear that he didn’t quite know what he was doing,” Metz said. “He was backward.”
The staff tweaked their habitat, swapping out the ground material and providing better digging spots for egg laying. The renovations worked. In November, Mommy buried a clutch of 16 eggs the size of billiard balls. On Feb. 27, the first baby hatched. Three siblings followed. Incubated at a minimum of 85.1 degrees, the hatchlings are most likely females. Temperatures below 82.4 degrees produce males.
“I always refer to it as cool dudes and hot chicks,” Metz said.
Visitors can watch the adults poke around a large outdoor space with two swimming holes. They are most active on sunny, warm days.
“They’re using their pools, and they’re in the mud wallows, and they are out moving around,” Augustine said.
For a closer encounter, the zoo offers a behind-the-scenes experience three times a week with the Galápagos and Aldabra tortoises. Tickets are $65, plus zoo admission.
Thirteen tortoise species are native to seven Galápagos Islands off the coast of Ecuador. In 2012, Lonesome George died in his home at the Tortoise Breeding and Rearing Center on Santa Cruz Island in the Galápagos. The centenarian was the last of the Pinta Island tortoises.
Tortoises typically reach their reproductive age at about 25 years old, so Mommy and Abrazzo won’t become grandparents anytime soon. But with a lifespan of 100 years or longer, they could become parents again.