 John managed, from his prison camp, to get in touch with Erwin Stresemann, who sent him rings to use in the camp and some useful literature, including the scarce first volume of Niethammer's Handbuch der Deutschen Vogelkunde, now in the Alexander Library at Oxford.In 1946 he became vice warden of Skomer Field Study Centre and as a member of West Wales Field Studies Council played a key part in establishing the original Bird Observatory committee.His life to retirement in 1979 was spent as Fellow of New College Oxford and reader in English literature in the university.