 The Réunion ibis or Réunion sacred ibis ( <unk> solitarius ) is an extinct species of ibis that was endemic to the volcanic island of Réunion in the Indian Ocean . The first subfossil remains were found in 1974 , and the ibis was first scientifically described in 1987 . Its closest relatives are the <unk> sacred ibis , the African sacred ibis , and the straw @-@ necked ibis . 
