Was there a Buckner(surname ) pirate? Lived in South America?
There is no record of a pirate with the surname, Buckner. Pirates are normally very private and their records are hardly available in the public domain. Pirates were also known as privateer, corsair or buccaneers.
I can't find anything about a pirate called Buckner. Do you perhaps mean buccaneer? The buccaneers were pirates who attacked Spanish shipping in the Caribbean Sea during the 17th century.