Letter from the 5th Earl of Cranbrook to Joe T. Marshall on recording of swiftlets clicking echo-location calls

Letter from the 5th Earl of Cranbrook to Leslie Kay informimg Kay he was sending over the original tapes of recordings of birds. He described the two tapes

Letter from the 5th Earl of Cranbrook to Lim Chan Koon commenting on Lim's draft on the taxonomic status of the glossy blue white-bellied swiftlets. Attached are two pages of a write-up with title "Introduction"

Letter from the 5th Earl of Cranbrook to Lim Chan Koon concerning Lim's draft application. He suggested some referees for Lim. Attached: part of Lim's manuscript: Section 6.3 Swiftlet nesting caves

Letter from the 5th Earl of Cranbrook to Lim Chan Koon discussing Lim's PhD programme

Letter from the 5th Earl of Cranbrook to Lim Chan Koon discussing Lim's PhD programme and the cost involved for his projects

Letter from the 5th Earl of Cranbrook to Lim Chan Koon suggesting that he observed swiftlets feeding their young and writing an article on it for Bulletin of the British Ornithologists' Club

Letter from the 5th Earl of Cranbrook to Ljubo Pecotich commenting on the nests of grey-rumped swiftlets and egg shell Pecotich sent to him

Letter from the 5th Earl of Cranbrook to Ljubo Pecotich concerning his observations of swiftlets in New Hebrides. He also mentioned about clutch-size of swiftlets of New Caledonia

Letter from the 5th Earl of Cranbrook to Ljubo Pecotich on swiftlets of Australia and New Hebrides