See inside an endangered California condor egg just before it hatches

A scan of a California condor (Gymnogyps californianus) egg has revealed a rarely seen embryonic world. The chick is the 250th condor hatched at a facility helping to bring back the threatened birds from the brink of extinction.

Like each condor egg laid in the San Diego Zoo Wildlife Alliance’s breeding program, this one was closely monitored by veterinary staff to ensure it was growing normally. As part of these regular check-ups, experts “candle” the developing eggs by placing a light against the shell to check the position of the chick inside.

All eggs have an air pocket inside, but this one was in an unusual position, which suggested the chick was contorted. Such a position can harm its chance of hatching successfully. The team decided to do a computed tomography (CT) scan to peek inside the shell – something they have had to do for previous eggs, too.

“We can see the skeleton and air pockets in the egg,” says Nora Willis at the San Diego Zoo Wildlife Alliance. “I’m still blown away by it.”

To their relief, the scan revealed that the chick inside was doing just fine. The condor chick even started “pipping” – one of the early stages of breaking through the shell. The team returned the egg to its nest, where its parents helped the young bird hatch on the morning of March 16. The team named the chick Emaay (pronounced “eh-my”), a word for “sky” from the language of the Kumeyaay, an Indigenous people of California.

The hatch of the new chick, whose sex is not yet determined, marks a notable milestone for the species, which narrowly evaded extinction. The chick’s father, Xol-Xol (pronounced “hole-hole”), was one of just 22 condors surviving in the 1980s that was brought into the breeding program. “It’s kind of like a full circle moment,” says Willis.