Gus was a male De Brazza's monkey born at the Bronx Zoo in 2000, and came to the Oregon Zoo in 2008 based on a recommendation from the Association of Zoos and Aquariums' species survival plan for De Brazza's monkeys. He was a favorite among the zoo's primate and Africa keepers, many of whom had worked with him for five years. Gus passed away in 2013, shortly before the birth of is only offspring, Augustus, who was named in his honor.