Story of the Week: 9 Galápagos Tortoises Born in Philly Zoo

The Philadelphia Zoo welcomed nine more Galápagos tortoises this week, the latest output of  Mommy and Abrazzo, the zoo’s oldest residents. The parents are estimated to be about 100 years old; Mommy has lived at the zoo almost as long, since 1932.

The new offspring join seven others that hatched earlier this year and made Mommy the oldest first-time mom of her species, an event that was reported on Saturday Night Live’s Weekend Update, of all places.

The hatchlings are part of the Association of Zoos and Aquariums (AZA) Species Survival Plan breeding program designed to preserve the genetic diversity of endangered species in captivity. The western Santa Cruz tortoise (Chelonoidis niger porteri) is a subspecies of the iconic Galápagos tortoise from Santa Cruz Island. The nine new arrivals bring the total AZA population in North America up to 60.

Heat is what separates the boys from the girls in this species, as the sex of Galapagos tortoises is determined by incubation temperature. If it’s below 82.4°F, you’ll get males; above 85.1°F produces females. (Left unsaid is what pronouns are applicable for hatchlings cooked in between those ranges.) Eggs typically take four to eight months to hatch, with females hatching first.

The subspecies is listed as critically endangered by the International Union for Conservation of Nature. Even on the protected Galápagos islands, the species is threatened by habitat loss and invasive species.

This week the Philly zoo is collecting names – and cash – for one of the baby males. When you make a $25 donation, you can enter a contest to name one of the new guys. The money will go to the zoo’s conservation programs. See here for more info.

Photo credit: Philadelphia Zoo