Letter from Roger Perry to the 5th Earl of Cranbrook concerning provision of tapes to the Earl to record animal sounds and the copyright of those recordings

Letter from Ronald Angus Macdonald to the 5th Earl of Cranbrook asking him if he had received Macdonald's draft paper on the Seychelles cave swiftlets

Letter from Ronald Angus Macdonald to the 5th Earl of Cranbrook informing of his intention of studying the Seychelles cave swiftlets, Aerodramus elaphra. He asked the Earl for advice

Letter from Roy Andries de Groot to the 5th Earl of Cranbrook requesting for personal information concerning his work with swiftlets

Letter from S. Coffin to the 5th Earl of Cranbrook concerning the invitation to tender for research contract relating to edible nest swiftlets. A draft specification of the proposed project was enclosed

Letter from S. Coffin to the 5th Earl of Cranbrook enclosing one copy of a signed contract between the Earl's organisation and the department covering the programme of research on edible nest swiftlets

Letter from S. Coffin to the 5th Earl of Cranbrook enclosing two copies of a contract between the Earl's organisation and the department covering the programme of research on edible nest swiftlets

Letter from S. Dillon Ripley to the 5th Earl of Cranbrook on identity of Philipines swiftlets

Letter from Sampurno Kadarsan to the 5th Earl of Cranbrook on considerations on swiftlet taxonomy

Letter from Sampurno Kadarsan to the 5th Earl of Cranbrook thanking Lord Medway for reports on swiftlets in Java. Attached: "Swiftlets collected in Java 1960-61"