Bonnie, a 30-year old whistling orangutan

Bonnie, a 30-year-old female orangutan living at the Smithsonian National Zoological Park in Washington, D.C., began whistling a sound that is in a humans, but not an orangutans, repertoire after hearing an animal caretaker make the sound. Bonnie is the first-known orangutan to imitate a sound from a human's vocal repertoire.