Critically endangered Galapagos tortoises become first time parents at nearly 100 years old

A pair of critically endangered, nearly 100-year-old Galapagos tortoises at the Philadelphia Zoo have just become first-time parents.

In an announcement last week, the zoo said it is “overjoyed” at the arrival of the four hatchlings, a first in its more than 150-year history. The babies are the offspring of female Mommy and male Abrazzo, the zoo's two oldest residents.

The quartet is being kept behind the scenes inside the Reptile and Amphibian House for now, “eating and growing appropriately,” the zoo said. They weigh between 70 and 80 grams, about the weight of a chicken egg.

The first egg hatched on 27 February, and more that still could hatch are being monitored by the zoo's animal care team.

“This is a significant milestone in the history of Philadelphia Zoo, and we couldn’t be more excited to share this news with our city, region and the world,” President and CEO Jo-Elle Mogerman said in a statement.

“Mommy arrived at the Zoo in 1932, meaning anyone that has visited the Zoo for the last 92 years has likely seen her," she added.

"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.”

Mommy is considered one of the most genetically valuable Galapagos tortoises in the Association of Zoos and Aquariums' species survival plan (AZA SPP). This programme aims to ensure the survival of the Western Santa Cruz Galapagos tortoise and maintain a genetically diverse population.

The species is listed as critically endangered by the International Union for Conservation of Nature (IUCN) with threats including human-wildlife conflict, the introduction of invasive species, and habitat loss.

"At one point, each of the Galapagos Islands had