Hornbills (Bucerotidae)

Writhed Hornbill (Aceros leucocephalus) - HBW 6, p. 512

French: Calao de Vieillot German: Mindanaohornvogel Spanish: Cálao Grande de Mindanao
Other common names: Writhe-billed(!)/White-headed Hornbill, Wrinkled(!)/Mindanao Wrinkled Hornbill

Taxonomy: Buceros leucocephalus Vieillot, 1816, Moluccas; error = Mindanao, Philippines.
Sometimes placed in genus Rhyticeros. May form a superspecies with A. cassidix, A. corrugatus and A. waldeni. Often considered conspecific with A. waldeni, but differs in plumage and bare-part colours, and in degree of sexual dimorphism in colour of facial skin. In the past, was sometimes treated as conspecific with A. corrugatus, but differs markedly in several aspects of morphology. Monotypic.

Distribution: Dinagat, Siargao, Camiguin and Mindanao (S Philippines).