The fifth Earl of Cranbrook is a specialist in swiftlet studies. Certain species of swiftlets build edible nests. The Earl worked in Malaya as well as spent time in countries like Indonesia that have swiftlets, especially the species that produce edible nests. The Collection consists of manuscripts, fieldnotes, photos, correspondence, description of swiftlet-related artefacts in various museums, published documents (journal articles, book chapters, books and dissertations, newspapers articles) some of which are authored or co-authored by the Earl.