Recently a researcher, Carel ten Cate of the Netherlands' Institute of Biology Leiden of Leiden University, found audio from 1987 of an Australian musk duck speaking.
Ripper, the duck says: "You bloody fool!"
Ten Cate stated:
"This came as a big surprise. Because even though the bird was recorded 35 years ago, it remained unnoticed by researchers in the vocal learning field until now. That makes it a very special rediscovery."
Ripper was also recorded making noises mimicking a pony, the cough of a caretaker and a squeaking door.
It is unclear why this particular species of ducks is capable of "vocal learning".