The Center had connections to Johns Hopkins University, and Olson was encouraged to enroll there for graduate school. He would matriculate at the School of Hygiene and Public Health in the Department of Pathobiology under Bernhard Bang. With the Smithsonian's backing, Olson went to Ascension Island and Saint Helena in 1970 and 1971, where he discovered the Saint Helena hoopoe and the Saint Helena crake. This work was the basis of his dissertation on the evolution of rails. Johns Hopkins would award Olson an Sc. D. in 1972.