Bray completed his bachelor's degree in botany at the University of Illinois in 1950, after three years of study.
Bray began working toward a doctorate under John Thomas Curtis at the University of Wisconsin–Madison in August 1950.
In 1955, Bray began teaching ecology at the University of Minnesota while working with Don Lawrence.
Bray resigned from his position at the University of Toronto in 1962, to protest the Canadian government placing nuclear weapons at present-day Iqaluit.
Soon after the Cuban Missile Crisis, both relocated to New Zealand in 1963, and began working for the Department of Scientific and Industrial Research.