Born in 1969, Dan is the first gorilla to have had a special kind of knee surgery. The surgery relieved the pain that Dan felt from arthritis in his knee. Dan's eyes are close-set, and he has the reddest hair of the three males. He's not as big as Zuri, but he has a larger, long oval-shaped head.

Dan left the Bronx Zoo in early 2001 and now lives in Omaha's Henry Doorly Zoo.

The bridge of Dan's nose is very narrow.