Nine Aldabra giant tortoises have hatched at Tulsa Zoo in Oklahoma! The hatchlings started to pip, or cut through their shells, on February 9. Several of the tortoise hatchlings are on now exhibit at the zoo. 

The hatchlings started out weighing a tiny 50 grams each, but they will get much bigger. Aldabra tortoises are the world's second largest tortoise species. The zoo has three adult males and two adult females. The adult male tortoises weigh nearly 400 pounds (181 kg), while the adult female tortoises weigh around 175 pounds (79 kg). Their ages range from 31 to more than 100 years old.

Photo credits: Tulsa Zoo / Sarah Floyd (1, 2, 4); Aaron Goodwin (3, 5)

The incubation period for these tortoises lasts from 95 to 120 days. Once the tortoises pip, it can take up to five days to fully emerge from the shell, and usually two to three more days before they are ready to be taken out of the incubator and placed on a substrate on exhibit. 

Aldabra tortoises live on the islands of the Aldabra atoll in the Seychelles. They are classified as Vulnerable on the International Union for Conservation of Nature's Red List of Threatened Species. 

Tulsa Zoo has now successfully hatched 109 Aldabra tortoises since it began its breeding program in 1999. The Tulsa Zoo is the only Association of Zoos and Aquariums-accredited institution that has an Aldabra tortoise breeding program, and the zoo is one of only two U.S. institutions to currently breed this species. Their first Aldabra tortoise hatchling emerged from its egg in the winter of 1999 and they have continued to collect fertile eggs every two to three years since that time.