Sulphur-billed Nuthatch (Sitta oenochlamys) [XC391268]
by Frank Lambert from Tanay, Rizal, Calabarzon, Philippines (call)
Sulphur-billed Nuthatch (Sitta oenochlamys) [XC617327]
by Frank Lambert from Trail to plateau, Samar National Park HQ, Eastern Visayas, Philippines (call)
Subspecies
Sometimes placed with Velvet-fronted Nuthatch (Sitta frontalis) and Yellow-billed Nuthatch (Sitta solangiae) in a separate genus, Oenositta. They may form a superspecies and have at times been considered conspecific. Possibly more closely related to Yellow-billed Nuthatch (Sitta solangiae), Hainan subspecies chienfengensis of which may form link between the two species (both are yellow-billed, whereas Velvet-fronted Nuthatch (Sitta frontalis) has red bill). Geographical variation partly clinal, colour saturation and dominance of lilac tones in plumage increasing from north to south through islands.
The following 6 subspecies are recognised:
mesoleuca (Ogilvie-Grant, 1894) - North-western Luzon (western Cordillera mountains), in northern Philippine Is.