The Sulu Horn-bill is the rarest horn-bill bird in the world. It is endemic to Sulu Islands in Philippine , Sanga-sanga island, Jolo island and Tawi-tawi island. The Sulu Horn-bill is distinctive from other horn-bill species by its distinctive pro-dominantly black color while the upper parts have a glossy green sheen and the tail is white, now it is extinct in Sanga-sanga and Jolo islands and only exists in Tawi-tawi island with fewer than 40 individuals , and it is classified as Critically Endangered according to the International Union for Conservation of Nature (IUCN) and listed on CITES Appendix 2 .
Threats are ,that the Jolo and Sanga-sanga islands are completely deforested because of logging , palm oil plantations, and Tawi-tawi island suffers from deleterious deforestation because of logging , conversion to rubber plantations , agriculture. Hunting for food and for target practice , poaching for bird trade.