Kenneth Allen (February 13, 1971 – December 1, 2000) was a Bornean orangutan at the San Diego Zoo. He became one of the most popular animals in the zoo's history because of his many successful escapes from his enclosures. He was nicknamed "The Hairy Houdini". Ken Allen was born in captivity at the San Diego Zoo in 1971. In 1985, he gained worldwide attention for a series of escapes from his enclosure, which had been thought to be escape-proof. During some of his escapes, his female companions joined him. Ken Allen's ability to outwit his keepers and his docile demeanor during his escapes resulted in fame. He had his own fan club, and was the subject of T-shirts and bumper stickers (most reading "Free Ken Allen"). A song about his escapades, "The Ballad of Ken Allen", was written by David Gersten. Ken Allen developed B-cell lymphoma and was euthanized on December 1, 2000. He was 29 years old.

Escapes

In his book about animal resistance, author Jason Hribal writes that Ken Allen "would unscrew every nut that he could find and remove the bolts" in his zoo nursery. In 1985, during his escapes on June 13, July 29, and August 13, Ken Allen peacefully strolled around the zoo looking at other animals. Ken never acted violently or aggressively towards zoo patrons or animals except for another orangutan called Otis, whom he despised. During his second escape, he was caught stoning Otis and he had to be led back to his enclosure. This attack is what led him to be put in solitary confinement. Zookeepers were initially stumped over how he had managed to escape. Staff began surveillance of his enclosure to try to catch him in the act, only to find that he seemed to be aware that he was being watched. (Prior to the August 13 escape, he was seen with a crowbar in his enclosure but tossed it aside -- as if uninterested -- when a staff member walked by. ) This forced zookeepers to go "undercover", posing as tourists to learn Ken Allen's escape route, but the ape was not fooled and continued to evolve his tactics. In April 1986, he escaped when the moat inside his enclosure was being repaired. After each escape, Ken Allen would be placed in solitary confinement until zoo staff figured out ways to prevent future escapes. Yet Ken Allen persisted, despite consequences -- including encountering electrical fencing on an escape attempt in 1986. Moreover, other orangutans followed Ken Allen's lead, escaping from their enclosure. In 1987, zoo officials hired experienced rock climbers to find every finger-, toe- and foothold within the enclosure, spending $40,000 to eliminate the identified holds. "Time" in 2011 listed Ken Allen's story as one of the Top Eleven Zoo Escapes.