He had no regular employment from 1926 until he was appointed superintendent of the Marine Biological Association’s Tees Estuary survey in 1929. Then in 1930 he was appointed Director of the Oxford Bird Census which developed into the Oxford University Research in Economic Ornithology in 1931, then an Institute of Field Ornithology, funded by the newly formed British Trust for Ornithology in 1933. In 1938, it was officially recognized by Oxford University as the Edward Grey Institute of Field Ornithology. In 1945 he retired as director and became the Institute's librarian, remaining so until 1955. The donation of his personal collection of bird books had provided the original nucleus of the library, and it was named after him in 1947.