Chestnut-backed Owlet Glaucidium castanotum Scientific name definitions

17–19 cm (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); c. 100 g (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Small owlet easily recognized by dark greyish breast with narrow white barring and bright chestnut upperparts with rufous barring (2 Ritschard, M. and Schweizer, M. (2007). Identification of Asian Glaucidium owlets. BirdingASIA. 7: 39–47. Close ); irides bright yellow; cere greenish; bill yellowish to greenish-horn (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Similar in shape and size to sympatric G. radiatum but differs from that species in darker and greyer head  ; entire upperparts  barred chestnut and blackish; and underparts white, barred dark on breast  and flanks  , but streaked olive-brown on belly. Juvenile plumage similar to that of adult but “with blurrier barring and streaking” (3 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ).

This and some other Old World owlet species placed in genus Taenioglaux by some recent authors (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close , 4 Mikkola, H. (2014). Owls of the World. A Photographic Guide. 2nd edition. Firefly Books, Buffalo, NY, USA. Close ). Present species possibly closest to G. radiatum; although both present in Sri Lanka, they occupy different habitats. Formerly treated as a race of either G. cuculoides or G. radiatum. Specific name previously given as castanonotum, but this spelling, and the date of publication, recently shown to be erroneous (5 Dickinson, E.C., Jones, C. and David, N. (2009). The correct spelling, date and citation for the Chestnut-backed Owlet of Sri Lanka. Indian Birds. 5(2): 52–53. Close , 6 Dickinson, E.C. and Pittie, A. (2006). Systematic notes on Asian birds. 51. Dates of avian names introduced in early volumes of the Journal of the Asiatic Society of Bengal. Zool. Meded. Leiden. 80(5): 113–124. Close , 7 Dickinson, E. C., and J. V. Remsen, Editors (2013). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition. Volume 1. Aves Press, Eastbourne, UK. Close ). Monotypic.

Sri Lanka.

Confined mostly to forests of wet zone, from lowlands to c. 1950 m (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); said to occur in dense forest (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ) but also to be scarce in that habitat (3 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). Has been recorded at edge of rubber plantation. Frequents tops of tall trees, usually on steep hillsides, and tends to occur in forest canopy.

Mostly insects; also mice, lizards and small birds; recorded eating a frog , and reported to catch geckos on tree trunks (3 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close ). Takes larger prey primarily when young being fed. Often hunts in daytime.

Short series (4–9 notes per phrase (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ) ) of far-carrying “krrraw”  notes; notes begin softly and then increase slightly in pitch and volume (3 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia: the Ripley Guide. Lynx Edicions, Barcelona, Spain. Close , 1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Commonly calls during day.

Very little information. Lays from Mar–May; nests in natural tree cavity or in nest hole built by woodpecker or barbet; clutch size usually 2; egg size c. 35 mm × 28 mm (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Not globally threatened. Currently considered Near Threatened. CITES II. Restricted-range species: present in Sri Lanka EBA. Uncommon; formerly fairly common in S half of island in hills and low country, to outskirts of Colombo, but range has shrunk greatly as a result of deforestation; found sparingly in forest remnants; still frequently heard in Sinharaja Biosphere Reserve. Global population roughly estimated at 15,000 to 30,000 individuals.