Letter from the 5th Earl of Cranbrook to Prof Andrew J. Berger informing him the scientific name for the Guam swiftlet was Aerodramus vanikorensis bartschi. He also requested Berger to send him information on swiftlets in Hawaii

Letter from the 5th Earl of Cranbrook to Prof David Norman on nest material of swiftlets, Aerodramus (syn. Collocalia)

Letter from the 5th Earl of Cranbrook to Prof J. David Pye inviting him to co-write a paper in memory of D. Lack

Letter from the 5th Earl of Cranbrook to Prof R. L. Usinger informing him he was sending to him three bug-ridden nests of Collocalia esculenta

Letter from the 5th Earl of Cranbrook to R. de Naurois on swiftlets of New Caledonia

Letter from the 5th Earl of Cranbrook to R. Kreuger concerning exhange of eggs

Letter from the 5th Earl of Cranbrook to Richard K. Brooke commenting on his work. He also discussed the Salanga swiftlet

Letter from the 5th Earl of Cranbrook to Richard K. Brooke concerning how the Australians classify swiftlets. He also discussed a document by Streubel

Letter from the 5th Earl of Cranbrook to Robin concerning Dr Stanley A. Temple

Letter from the 5th Earl of Cranbrook to Roger Perry saying he did not want to be obligated to produce tapes that were of high quality for permanancy. However he would take his recordings to B. B. C. when he returned to England and let them decide whether to purchase them or not