Discovery Island Nature preserve at Walt Disney World; opened on April 8, 1974 as Treasure Island; name changed in 1977. It closed on April 8, 1999. An 11.5-acre island paradise, Discovery Island was home to many exotic birds and animals. Originally the island was themed to the Disney film Treasure Island, and a wrecked ship from that incarnation could still be seen on the shore. One of the largest walk-through aviaries in the world was featured, and guests might come upon giant tortoises. Since the area was a wildlife sanctuary, Disney curators helped the government try to save the species of Florida dusky sparrows by beginning a breeding program, but the last pure dusky sparrow passed away of old age on the island.