Beethoven joined the study community in December, 1973 at the age of four. He arrived with Harmony, who was probably his older sister. It seems likely that their mother had recently died, and 9 year-old Harmony "adopted" her younger brother. Beethoven was a serious little chimp and didn’t play much. He interfered desperately whenever he saw males mating. He remained small and took a long time to reach adult size. Interestingly, Beethoven "adopted" a young female chimp later in his life. He formed a close bond with a young orphan named Dilly, whose mother had disappeared. As Dilly grew up, she and Beethoven spent a great deal of time together, travelling as a pair, grooming frequently, and nesting near each other at night. For years, we wondered why these two had such a close relationship. Did Beethoven remember what it was like to be an orphan, taking pity on this young chimp, or was something else going on? In 1999, we learned something that may explain this unusual bond. DNA analysis showed that Beethoven is probably Dilly's father. While this is the first known father-daughter "adoption", perhaps it indicates that male chimps are indeed able to sense who their children are.

Beethoven is one of my favorite chimps. He has a very unusual face (I think he looks a lot like his namesake!), and has some great facial expressions. This is very obvious when he is begging for meat. He rarely catches his own prey, and is extremely persistent in his efforts to get some meat from those that do. He sits very close to the meat possessor, grinning and grimacing as he tugs on the carcass and clasps his hands over the possessor’s mouth. He never gives up, always returning after he is chased away. Because of this, he is very successful in persuading higher-ranking males to give him a piece of their catch.