Zoo always thought this gorilla was a male — until she gave birth to surprise newborn

It’s always an exciting day for a zoo when a new baby animal is born, especially when it’s a member of an endangered species. But one new birth came as a huge shock to zookeepers for a big reason.

On July 19, the Columbus Zoo and Aquarium announced some inspiring news: a western lowland gorilla was unexpectedly born at the zoo, providing a new addition to their gorilla family and some great news for this critically endangered species.

But the news came as quite a shock to zoo staff: the baby’s mom, an 8-year-old gorilla named Sully, had always been believed to be a male!

“It’s hard to tell the sex of younger gorillas,” the Columbus Zoo explained in a blog post. “Until about age 8, males and females are about the same size, and they don’t have prominent sex organs.” The silver backs and head bumps that distinguish males don’t appear until about age 12.

They also explained that they had taken a hands-off approach in Sully’s upbringing: she was well-cared for by her mother and never required any medical intervention.

And while gorillas have a gestation period of about 8.5 months, they do not show any outward signs of pregnancy due to their large abdomens and small size of their newborns, allowing for quite the shock when the “male” gorilla suddenly gave birth.

In their press release, the zoo said that the newborn was a female (they got a second opinion from a primate expert at another facility, perhaps to avoid any more future surprises) and that the baby was bonding well with Sully, who is “taking good care of her.”

A DNA test will reveal who the baby’s father is, but the whole gorilla troop is reportedly supporting Sully and her baby. The gorilla habitat has reopened to zoo guests, who will be able to spot Sully and her baby, though the gorillas will also have access to behind-the-scenes area for their comfort.

The unusual circumstances aside, the baby’s arrival is great news for the western lowland gorilla, a critically endangered species that has been affected by habitat loss, deforestation and the bushmeat trade.

It marks the 34th gorilla born at the Columbus Zoo, who in 1956 became the first zoo to welcome a newborn gorilla. The zoo has been part of efforts to support gorilla conservation in the wild and they are known for their care of gorillas.

We’re so glad Sully and her newborn are doing so well! What a crazy surprise and such good news for this critically endangered species!

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