The Jourdain Society is or was a controversial society based in the United Kingdom, its aims being ‘the advancement of the science of oology’, the collection and study of intact birds' eggs. Originally the British Oological Association, it changed its name in 1946 in memory of distinguished ornithologist and oologist Reverend Francis Jourdain (1865–1940). The society was a social gathering that held regular dinners.
Egg-collecting is the removal of intact, unhatched eggs from a birds' nest, followed by drilling out the contents to keep the egg intact. It was considered a respectable leisure pursuit in the nineteenth and early twentieth century, at a time when conservation, study and hunting were not seen as opposed activities. However the activity became extremely controversial after conservation groups concluded that the taking of rare birds' eggs was a major factor in the extinction and endangerment of rare species, and that the activity was without any real scientific value. The collection of new eggs was made illegal in 1954 by the Protection of Birds Act, and from this point the society was widely believed to act as an information exchange for a hard core of egg-takers and their customers. Its gatherings of often wealthy collectors were several times raided by police, one raid in 1994 leading to six convictions. The society at one stage held charitable status but later ceased holding this. A spokesman claimed in 1994 that it expelled members with convictions and in 1998 that the society was composed of "first-class field naturalists who carefully study breeding habits".
Jourdain's collection is currently held by the Oxfordshire County Museum.