IN PARTNERSHIP WITH CHILDREN’S HOSPITAL COLORADO – On the green hills in Primate World, guests can often spot Western lowland gorilla, Sully, exploring alongside his family. As he approaches his first birthday, Sully is becoming more curious and confident every day, spending time with his mom, Asha, his aunt, Kwisha, and his dad, Goma. Whether he’s playing, learning from his family, or keeping a close eye on the world around him, Sully helps teach guests about gorillas through his expressive brown eyes, playful antics, and natural curiosity.
In partnership with Children’s Hospital Colorado, Cheyenne Mountain Zoo is throwing a birthday party for sweet little Sully on Tues., July 21, 2026 – and you’re invited!
Sully’s 1st Birthday Party
Tues., July 21
10 a.m. to noon
Primate World (Outside Gorilla Viewing Area!)
Advance daytime admission to the Zoo is required and limited.
10 a.m. to noon
-Learn about gorillas from our amazing team of docents at booths.
-Make a birthday card for Sully!
-Visit Children’s Hospital’s photo booth – complete with animal props to pose with!
-Participate in healthy activities, led by our partners at Children’s Hospital.
10 a.m.
Watch special enrichment for Sully and the troop.
11:15 a.m.
Get to know Sully and the gorilla troop during a special Western lowland gorilla keeper talk.
11:30 a.m.
Help sing happy birthday to Sully!
“Sully has been an incredible — and adorable — addition to Primate World over the past year, and we’re excited to welcome everyone to the Zoo to celebrate this little one’s growing milestones,” Ashton Asbury, lead keeper in Primate World, says. “Sully is growing up strong and curious, thanks to the patient and attentive care from his mom, Asha. He’s exploring solid foods, picking up important social behaviors from the troop, building trust with keepers, and growing more playful every day. It’s impossible not to love him!”
Sully is reaching key milestones throughout his first year that show he’s growing well, including trying solid foods, curiously exploring his surroundings, playing with members of the troop, and building trust and relationships with his care team. Similar to many animal species, human babies also experience multiple changes in their first year of life. Learn more about a human baby’s first-year milestones and health checks from our partners at Children’s Colorado here.
When Sully was born, it had been nearly 13 years since a gorilla was born at CMZoo. This little one is Asha’s third baby and the first for silverback dad, Goma. Goma moved to CMZoo, in 2016, on a breeding recommendation from the Western Lowland Gorilla Species Survival Plan, supported by Association of Zoos and Aquariums-accredited organizations, including CMZoo.
The birthday party is open to all members and guests with advance tickets to the Zoo, which are available at cmzoo.org. Summer daytime admission sells out fast, so don’t wait long to make your timed ticket reservation!
Western lowland gorillas are critically endangered in the wild, and their numbers continue to decline. Gorilla fans can help preserve wild gorilla habitats by recycling small electronic devices and cell phones at CMZoo.
In addition to disease and poaching, gorillas face habitat loss due to logging for agricultural use, human settlements and mining. Many of the West African lowland forests and swamps that these animals call home are also natural deposits of coltan, a mineral used in cell phones and other electronics. Due to the ever-increasing demand for cell phones across the world, the destruction of these gorillas’ habitats for mining purposes has unfortunately increased.
Coltan is recyclable, and by donating old cell phones, we can help supply valuable coltan for future phone production. Guests can bring electronics to CMZoo admissions or Primate World, where there’s a recycling collection bin near the gorillas’ indoor dens. CMZoo will send them to Eco-Cell, an organization that recycles the phones, as well as tablets, smart watches, Bluetooth devices, GPS devices, e-readers, digital cameras, handheld gaming systems and their accessories.