Columbus Zoo and Aquarium finds out male gorilla is female when she gave birth.Photo:Columbus zoo/Facebook

Columbus zoo finds out male gorilla is female when she gave birth

Columbus zoo/Facebook

It’s a girl! And it’s also another girl!

Columbus zoo finds out male gorilla is female when she gave birth

According to thezoo’s official blog, such a situation occurs because it can be difficult to tell the sex of a gorilla when they are young.

“Until about age 8, males and females are about the same size, and they don’t have prominent sex organs,” the blog stated. “As gorillas age, they become sexually dimorphic, meaning males and females look very different. However, males don’t develop their characteristic large size, silver backs, and large head bumps (called sagittal crests) until age 12 or later.”

Sully was not born at Columbus Zoo, and her original carers maintained a “hands-off approach in their care,” which may explain why her previous home thought the new mom was a male.

“Upon arriving at the Columbus Zoo,” the blog explained, “Sully was a young and healthy animal and did not need any procedures requiring immobilization that would have led to this discovery sooner.”

Additionally, female gorillas tend to have large and distended bellies, making identifying a pregnancy challenging. Typically,female gorillasreach sexual maturity between eight to 10 years of age.

“The infant appears to be healthy, and first-time mom Sully is taking good care of her,” the zoo posted to its blog. “The veterinary and animal care teams have not yet approached the infant, giving them time to bond with one another and with the rest of the troop, but will conduct a wellness exam soon.”

Columbus zoo finds out male gorilla is female when she gave birth

Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories

source: people.com