Miss Kay' Robertson appears in an early episode of 'Duck Dynasty: The Revival,' but health issues have kept her from filming more episodes.

WEST MONROE, La. (AP) — Phil Robertson, who turned his small duck calling interest in the sportsman's paradise of northern Louisiana into a big business and conservative cultural phenomenon, died May 25, according to his family. He was 79.

Phil Robertson, the bearded patriarch of "Duck Dynasty" and a former starting quarterback at Louisiana Tech, died, his family announced Sunday. He was 79. No cause of death was given, though his son Jase Robertson revealed in December on the family podcast that his father was in the early stages of Alzheimer's disease.