The papers contain biographical and autobiographical material, records of Elton's expeditions, fieldwork and surveys including photographs, his natural history notebooks, and correspondence. During his later years Elton devoted much time and effort to autobiographical writing and, although he did not produce a full-scale autobiography, he did prepare narratives of his family background, school, military training, student days, and notes on his books, geological, meteorological and ecological interests, and on his brother Geoffrey. Amongst the material he assembled in connection with this activity are records relating to the Bureau of Animal Population (BAP), his university teaching and his work for the Nature Conservancy.
There are records, principally diaries and photographs, of the four Arctic expeditions, 1921-1930, three visits to Denmark, 1953-1962, and four visits to tropical America, 1965-1973. As Elton had no contemporary diary in respect of the 1921 Spitsbergen expedition, he prepared, 1978-1983, a general account with photographs specifically for archival deposit. There are notebooks used by Elton for his natural history notes, 1914-1987, records of an ecological survey at Leckford, Hampshire, 1938-1939, and of ash bark beetle research carried out in Wytham Woods, Oxfordshire and at the BAP, 1948-1964, and photograph albums covering a wide range of locations and habitats including Leckford, Wytham and Nature Conservancy areas, 1927-1963. Also of interest is the notebook kept by Elton to record his Garden Mastership of Corpus Christi College, Oxford, 1938-1945. There is substantial correspondence with colleagues who began their research careers at the BAP including R.S. Miller, C. Overgaard Nielsen and P.W. Crowcroft, the author of a history of the BAP Elton's Ecologists (Chicago University Press, 1991). Other correspondents include the Russian ecologist N.I. Kalabukhov and colleagues with whom he established contact in connection with the later interest in the ecology of the tropical rainforest.