20th century. A major cause of the crash is predation by the South American gray fox, which was introduced to Tierra del Fuego in the 1950s to control rabbits. A Memorandum of Understanding was negotiated in 2006 with Argentina and Chile under the Bonn Convention in an attempt to safeguard the remaining migratory Tierra del Fuego/mainland population. References Further reading Geese Chloephaga Birds of the Falkland Islands Birds of Tierra del Fuego Birds described in 1861 Taxa named by Philip Sclater