A study of mitochondrial DNA of the spoonbills found that the black-faced and royal spoonbills were each other's closest relatives. Out of the six Platalea species within the family Threskiornithidae, the black-faced spoonbill is the rarest.
The black-faced spoonbill (Platalea minor) is a species of wading bird in the ibis and spoonbill family Threskiornithidae, found in eastern Asia. This species has the most restricted distribution of the six spoonbill species, and it is the only one regarded as endangered. Spoonbills are large water birds with dorso-ventrally flattened, spatulate bills. These birds use a tactile method of feeding, wading in the water and sweeping their beaks from side-to-side to detect prey. Confined to the coastal areas of eastern Asia, it seems that it was once common throughout its area of distribution. It currently breeds only on a few small rocky islands off the west coast of North Korea, with four wintering sites at Macau, Hong Kong, Taiwan and Vietnam, as well as other places where they have been observed in migration. Wintering also occurs in Jeju, South Korea, Kyushu and Okinawa, Japan, and the Red River delta in Vietnam. More recently, sightings of black-faced spoonbill birds were noted in Thailand, the Philippines, and additional sites in China.