The Cinnamon Ibon Hypocryptadius cinnamomeus is a forest canopy sparrow

The Cinnamon Ibon inhabits the canopy of cloud-forest of Mindanao Island in the Philippines, and has until now been classified as an aberrant member of the Zosteropidae (white-eyes). We assessed the systematic position of this enigmatic species using DNA sequence data (two mitochondrial markers, two nuclear introns and two nuclear exons) and broad taxon sampling. The species was robustly placed among the granivorous passeroid clades, as a basal branch in the family of true sparrows, Passeridae. Morphological data lend further support, as the Cinnamon Ibon shows similar specialization of the skull as other granivorous passeroids. The species' restricted distribution in the montane cloud-forest of the island of Mindanao, which is of oceanic origin, is difficult to explain without assuming an over-water dispersal event.