The British Library of Wildlife Sounds (BLOWS) collects and preserves recordings of all kinds of animal sounds for research and education. Established in 1969, it has the foremost collection of its kind in Europe, with recordings of 7,000 species of birds, mammals, amphibians, reptiles, fish and insects. The collection is worldwide in scope but is particularly strong on the fauna of western Europe. Many recordings are accompanied by detailed behavioural notes and they are invaluable in ethological and taxonomic research. By agreement with contributors, copies of most recordings and sonograms can be supplied for research. BLOWS also gives advice on recording techniques and on the availability of recordings worldwide, and maintains strong links with other major bioacoustic archives. Thanks to the generosity of many contributing recordists and scientists, BLOWS collections are expanding rapidly, but more recordists are urged to deposit copies or their original recordings for safe storage and to make them more widely available to the scientific community.