NEW YORK (AP) _ Ersel Hickey, a rockabilly singer best known for ``Bluebirds Over The Mountain,'' has died at age 70, according to a longtime friend. Hickey had been hospitalized at NYU Medical Center after surgery to have his bladder removed because of a tumor, according to Johnny Vallis, a friend and sometime publicist for the singer. He died after coming down with an infection, Vallis said. Hickey, a native of Brighton, N.Y., started singing in his teens, as a solo act and also with R&B groups. His first record, released in the late 1950s, was ``Then I'll Be Happy/Baby You're No Good.'' But he is best known for his 1958 hit ``Bluebirds Over The Mountain,'' which he also co-wrote. It was re-recorded by The Beach Boys a decade later. He also wrote songs for other artists, including Jackie Wilson's ``The Millionaire'' and LaVern Baker's ``A Little Bird Told Me So.'' Hickey had no survivors, according to Vallis.