Siau Scops-owl (Otus siaoensis)

Probably part of a species-group centred on O. manadensis (which see). Known from a single specimen. Until recently, treated as conspecific with O. manadensis, but separated during analysis that established O. collari, to which it is closest in morphology but from which it differs in its much smaller size (127 vs mean 161; allow 3); longer ear-tufts (at least 1); “more heavily marked and less conspicuously pale” throat (1); lack of “prominent pale nuchal collar” (2); “much more vermiculated, more regularly barred, and drabber” underparts (2); “fewer bands” on remiges and rectrices (ns[1 or 2]); “much more broadly, irregularly, and less strongly banded” tail (ns[1 or 2])#R. Monotypic.