In 1949 he oversaw Part 3 of The National Parks and Access to the Countryside Act 1949 which established the Nature Conservancy, a British state research council for natural sciences and 'biological service', and allowed for the legal protection of National Nature Reserves and Sites of Special Scientific Interest (SSSI).
From 1951 to 1960 he was the senior editor of "British Birds" and was the chief editor of The Birds of the Western Palearctic ("BWP", 1977-1994, OUP) from 1965-1992.