Cheyenne Mountain Zoo celebrates first birthday of baby gorilla Sully

COLORADO SPRINGS, Colo. (KRDO) -- A baby gorilla at the Cheyenne Mountain Zoo has officially turned one after the zoo celebrated his birthday with guests and zoo staff.

Sully, a western lowland gorilla, has been with the zoo since he was born on July 21, 2025, and is now celebrating his first birthday. The zoo worked with Children's Hospital Colorado on organizing events for visitors throughout the morning.

Guests were able to watch Sully receive a special birthday treat and hear all about gorillas from the experts.

Six-year-old Emilia, who was visiting the zoo with her family, says she even got the chance to feed Sully some greens and birthday "cake." She's a frequent visitor to the zoo, and says her favorite exhibits are the tiger and apes.

"It was really exciting. I was tossing greens, and they made a little birthday cake out of gorilla food. They were slimy, though," Emilia said.

On top of learning about the gorillas, attendees were able to take part in the celebration, including making birthday cards and singing "Happy Birthday" for Sully.

According to the zoo, Sully has made major milestones over the last year, including trying solid foods, playing with members of the troop and working with his care team. One of the team members says this first year of Sully's life has been one of the best of her own.

"Seeing him interact with the troop and getting to know keepers and starting to see and recognize guests," Ashton Asbury, lead animal keeper in Primate World, where Sully lives, said. "You can always tell when he recognizes you because he'll make a beeline over to the glass, and he likes to hit it with both of his hands. He'll do little spins to initiate play. That probably has been my favorite part of getting to know him and see him grow up over the past year."

Sully's mom, Asha, and silverback gorilla dad, Goma, have continued to care for him over the year. Sully is Asha's third baby and Goma's first.

Sully was the first gorilla born at the Cheyenne Mountain Zoo in 13 years, according to zoo officials. Western lowland gorillas are listed as critically endangered, according to the World Wildlife Fund.

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