Male and female gibbons sing duets in time with each other
https://www.newscientist.com/article/2354278-male-and-female-gibbons-sing-duets-in-time-with-each-other/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home
Male and female gibbons sing duets in time with each other