Manus Masked-Owl Tyto manusi Scientific name definitions

Taxonomic note: Split. This account was originally published under a single species in HBW Alive, but in Birds of the World it covers multiple species. We present that original content here, with the goal of developing a more refined species account for this taxon moving forward. Please consider contributing your expertise to update this account.

c. 33–46 cm (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); wingspan c. 90 cm (2 Mikkola, H. (2012). Owls of the World: A Photographic Guide. First edition. Christopher Helm, London, UK. Close ). The only Tyto known from the archipelago: separated from smaller Manus Hawk-owl (Ninox meeki) by prominent facial disc, black eyes and buffy-brown upperparts (3 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ). Distinguished from other masked-owls by combination of dark upperparts, rufescent brownish-buff underparts with large blackish spots, and black tail with narrow, irregular, yellowish-brown bars. Type specimen, collected 1913, is male with wing 275 mm, compared with second known specimen, a female with wing 301 mm, indicating that, as with other masked-owls, female is larger than male. Iris blackish brown, bill cream-coloured to pinkish white, and to yellowish grey to greyish brown (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Juvenile plumage undescribed, although presumed to be very similar to that of T. novaehollandiae (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Forms superspecies with T. novaehollandiae, T. aurantia, T. sororcula, T. nigrobrunnea and T. inexspectata. Sometimes considered conspecific with T. novaehollandiae. Evidence (subfossil bones) (3 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ) of extinct populations from Mussau and New Ireland may refer to undescribed races of present or closely related species, perhaps also isolated on single islands, and suggests that masked-owls may once have occurred more widely in Bismarck Archipelago. Monotypic.

Manus I, in Admiralty Is.

Rainforest; perhaps confined to hilly terrain at higher elevations (Manus I reaches 702 m), although all records have been at 200–250 m elevation (3 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ); has been found roosting in caves (3 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ).

Undescribed, though diet probably comprises small rodents, other small vertebrates and larger insects (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Described as being duller and harsher than T. aurantia (3 Dutson, G. (2011). Birds of Melanesia: The Bismarcks, Solomons, Vanuatu and New Caledonia. Christopher Helm, London, UK. Close ).

Undescribed, although is assumed to nest in tree-hollows (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

VULNERABLE. CITES II. Restricted-range species: present in Admiralty Islands EBA. No recent records. Population assumed to number fewer than 1000 mature individuals within overall range of 1900 km². Failure to find this owl during a 1990 survey suggests that it is confined to areas away from human settlement (not visited during survey), possibly explaining its unfamiliarity to local inhabitants, who occupy coastal areas, access inland being limited to a single road in E Manus. Type specimen was collected near a coastal settlement, suggesting population decline since 1913, although numbers probably always small. In 1987, 80% of vegetation on Manus was estimated to be primary forest but large areas in lowlands are now logged or under concession, and in coastal areas forest is being eroded by shifting cultivation, while introduced mammalian predators, e.g. dogs and cats, may be implicated in the species’ rarity; however, the brown tree snake (Boiga irregularis), which has decimated birds on Guam, is thought to be native to Manus and therefore might not pose a serious threat. Further research and census work required.