Columbus, Ohio – A heartwarming surprise unfolded at the Columbus Zoo in Ohio as zookeepers were astonished to learn that Sully, an 8-year-old western lowland gorilla, was, in fact, a female.
The revelation came to light when Sully was found cradling her newborn baby girl in her arms.
Sully had been a resident at the Columbus Zoo since 2019, living alongside her mother and fellow troop members. For five years, zookeepers had believed her to be a male, a common challenge in distinguishing the sexes of young gorillas. Until the age of around 8, male and female gorillas appear similar in size and lack prominent sex organs, making gender identification challenging.
In a statement released by the zoo after Thursday’s birth, they explained the complexities of identifying the sex of young gorillas.
As they mature, males and females undergo sexual dimorphism, leading to distinct differences in appearance. However, male gorillas do not fully develop their characteristic features such as large size, silver backs, and prominent head bumps, known as sagittal crests, until the age of 12 or later.
Sully’s health had been stable, and she had not required any medical procedures or attention that would have led to the earlier discovery of her true gender. The gestation period for gorillas lasts approximately 8 1/2 months, indicating that she became pregnant late in the fall.
“
In December 1956, the Columbus Zoo was the first zoo in the world to welcome the birth of a baby gorilla. For the next 67 years, we have continued to make vital contributions to gorilla conservation. By sharing some additional details about this recent heartwarming news, we hope to inspire you to join us in our mission to protect the future of this amazing species,” the Zoo said in a statement.
Detecting pregnancies in gorillas is challenging as they rarely exhibit outward signs due to the relatively small size of their newborns compared to human babies, and the natural larger size of their abdomens.
“The troop is supportive of Sully and the infant, and they will remain as a social group,” assured the zookeepers. “The infant appears to be healthy, and first-time mom Sully is taking good care of her.”
In order to allow sufficient bonding time between Sully and her baby girl, zookeepers have refrained from approaching the newborn just yet. Eventually, veterinarians will conduct a wellness examination on the infant. Additionally, a DNA test will be performed to determine the identity of the baby’s father.
Sully and her adorable baby girl are part of a troop led by the 39-year-old silverback Mac.
“It’s hard to tell the sex of younger gorillas. Until about age 8, males and females are about the same size, and they don’t have prominent sex organs. 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,” the zoo said of the unexpected birth.
The zookeepers and visitors alike are thrilled by this unexpected development, and the troop’s harmonious support has warmed the hearts of everyone at the Columbus Zoo. The duo is now being closely observed by zoo staff, and visitors are eagerly awaiting a glimpse of the delightful mother-daughter bond.