IUCN  recognizes 3 species at present, merging the Hawaiian and South American birds with the Black-necked Stilt; consequently, none of the three is listed as threatened species . Great Hornbill The Great Hornbill also known as Greater Indian Hornbill, Great Pied Hornbill and Two-horned Calao, is one of the larger member of the hornbill  family. The Great Hornbill