Gibbon Uses Slamming Door In Her Singing...
Tool use in apes is not unheard of, but this gibbon has taken it to a whole new level by enhancing her singing with the sound of an enclosure door slamming:Each time her song reached its natural climax, the gibbon slamme...
https://www.neatorama.com/2009/07/16/gibbon-uses-slamming-door-in-her-singing/
