The following is a news release from the City of Idaho Falls.
IDAHO FALLS, Idaho (News Release) The Idaho Falls Zoo is deeply saddened to announce the passing of Sid, the zoo’s male gray gibbon. Sid’s story has long been a special one, and his loss is felt profoundly by zoo staff, volunteers and visitors who came to know and love him.
Sid was born at the Idaho Falls Zoo under unique circumstances. His mother, Shannon, refused to care for him and ultimately abandoned him. After repeated attempts to encourage maternal bonding, the zoo’s animal care team stepped in to provide round-the-clock care, ensuring Sid received the nourishment and attention he needed to survive.
As Sid matured, reintroducing him to his gibbon family was initially successful, but over time he faced social challenges that made it unsafe for him to remain with the other gibbons. Zoo staff created a separate habitat designed for Sid’s safety and comfort, with enrichment and continuous care.
Over the past two years, Sid exhibited physical indicators of a gastrointestinal medical condition. Despite multiple treatments, sedated procedures and ongoing monitoring by the zoo’s veterinary team and external primate experts, his condition worsened. While he received constant attention, it is believed that the stress of living apart from his family may have exacerbated his medical condition. After extensive consultation, it became clear that his suffering could not be alleviated, and the difficult decision was made to humanely euthanize him to prevent further suffering.
“Sid’s lack of response to all therapies and treatment was disheartening, to say the least,” said Dr. Kasey Lucore, veterinarian for the Idaho Falls Zoo. “However, our keepers and vet team couldn’t allow any more suffering, and while euthanasia was the hardest choice for us, it was the kindest choice available for Sid.”
Sid received extensive care from medical professionals and was deeply cherished by the zoo staff, who supported him every day and are heartbroken by his loss.
“This decision was not made lightly,” said David Pennock, Executive Director for the Zoo. “Sid’s care team loved him deeply—they’ve been part of his story since the day he was born—and saying goodbye was incredibly hard for everyone who knew him.”
Sid was known for his playful curiosity and frequent interactions with guests near the viewing glass. He brought joy and laughter to countless visitors over the years and will be greatly missed by his keepers, volunteers and the entire zoo community.
A video memorial celebrating Sid’s life can be viewed on the Idaho Falls Zoo’s Facebook page.
