The Museum of Life and Science euthanized an 18-year-old black bear last week after discovering an inoperable cancerous mass, the Durham museum announced Monday.

Gus had been part of the museum experience since arriving as a cub in 2006.

Staff had noticed a dramatic change in his behavior, according to a news release. Veterinarians from the N.C. State University College of Veterinary Medicine discovered the mass near his heart and lungs during an examination and, based on his prognosis and age, euthanized him on Wednesday.

“Gus was one of those souls that brought people (and bears) together,” said Sherry Samuels, senior director of Animal Care at the museum. “His behavior with other bears, young and old, as well as what he did on his own, has made many of us smile, laugh, moan, roll our eyes, and just look at him in awe.”

Black bears generally live no more than 10 years in the wild, though the oldest was known to be 26, according to the N.C Wildlife Resources Commission.

Gus’ body and cells will be donated to cancer research organizations, to better understand and treat cancer in both humans and animals, the museum said

Orphaned as a cub

The museum is an Association of Zoos & Aquariums-accredited facility that is home to rescued black bears, lemurs, endangered red wolves, and more than 60 species of live animals.

Gus arrived at the museum from the Virginia Department of Game and Inland Fisheries as an orphaned 5-month-old cub after Wildlife officials determined he could not be released into the wild.

Known to staff as ‘Mama Gus,’ Gus raised several of the museum’s bears as they grew over the years. Little Bear, Murray, and the late Yona learned bear behaviors from Gus thanks to his patient nature, the news release stated.

“While I sit with this huge hole, I also have immense gratitude,” Samuels said. “Gratitude for how Gus impacted so many so positively. Gratitude for the veterinary team who cared for Gus so quickly and thoughtfully in his last days and minutes. I am so appreciative that Gus will live on not just in stories told of him by people I know, but likely hundreds if not thousands of people I don’t.”

For more about Gus and his life at the Museum, check out this tribute on the Museum blog.

About the Museum of Life and Science

The Museum of Life and Science’s 84-acre campus includes a two-story science center, one of the largest butterfly conservatories on the East Coast, and landscaped outdoor exhibits. Last year, the museum celebrated its 75th anniversary.