Family Typical Owls (Strigidae)

Critically Endangered

Siau Scops-owl (Otus siaoensis)


French: Petit-duc de Siau German: Siau-Zwergohreule Spanish: Autillo de Siau

Scops siaoënsis


, 1873,



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.

What do (1) and (2) mean? Learn more about the scoring system.

Siau I, N of Sulawesi.

Descriptive notes

Only known specimen measured 19 cm; wing length 125 mm; tail length 55 mm; no data on mass. Small scops-owl (distinctly smaller than nearest congeners, O. manadensis... read more


Recently described as a rolling, two-note “"Ook-grrrrah” that lasts c. 0·7 seconds and is... read more


Like its close congeners, assumed to inhabit forest.

Food and feeding

No information.


No information.


No information.

Status and conservation

CRITICALLY ENDANGERED. CITES II. Restricted-range species: endemic to Siau I, N of Sulawesi and present in Siau EBA. Known only from the holotype, collected in 1866. Given... read more

Recommended citation

del Hoyo, J., Collar, N., Sharpe, C.J. & Marks, J.S. (2019). Siau Scops-owl (Otus siaoensis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 9 December 2019).