The contents of the series are focussed chiefly on the years 1961-1967 and 1970 and are concentrated in files SZ/WWF/2 Correspondence, 1961-1971, 1975, 1981, and SZ/WWF/6, Now or Never, 1970.
File SZ/WWF/1, Minutes and Documents, 1962, 1965, consists only of the Fund's balance sheet and accounts for 1962, and minutes of the meeting of the Fund's Council, 14 October 1965.
File SZ/WWF/4, Elsa Appeal, and Joy Adamson, 1962, relates to a tour of Britain in 1962 by Joy Adamson. Her Elsa Appeal operated under the auspices of WWF, and Zuckerman chaired her lecture and film show in Birmingham on 12 October 1962.
File SZ/WWF/6 relates to the premiere of the film Now or Never at the National Film Theatre on 28 October 1970. This was a major fund-raising event in support of WWF's campaign to save the white rhinoceros, and Zuckerman was one of the organisers.
File SZ/WWF/7 is a slight file relating to a symposium and dinner on 8 May 1971 organised by an offshoot of WWF, the 1001. Zuckerman summed up the proceedings and the file contains a programme; typescript summaries of papers by W.G. Conway of New York Zoological Society and various senior members of the Zoological Society of London's scientific staff; and Zuckerman's MS speaking notes.