Google - who invented the very first duck whistles and when was it made?

Duck Calls have been used as far back as 1678 it has been thought that they were first used in the far east.

The first non-patented duck calls were made during the 1850s, the first patent was awarded to a man called Elam Fisher in 1870. Fred Allen had created the first external duck calls but was never awarded a patent.

In 1972 Phil Robertson created the famous Duck Commander call and built his own company in 1973.

This information was found on Wikipedia. Just search "duck call"