The Convention on Migratory Species (CMS) has long been associated with efforts to protect the endangered Siberian Crane. The Memorandum of Understanding concerning Conservation Measures for the Siberian Crane (Grus leucogeranus) -the Siberian Crane MOU - was the first one to be developed under the auspices of CMS. It was concluded on 1 July 1993 and revised on 1 January 1999.Since then, the Siberian Crane MOU has been of great value to the Convention. This historic memorandum has consequently long served as an example to many of the other MOUs on the conservation of migratory species concluded to date under CMS.