Justification This species is restricted to a small island and is very poorly known. Comparison with the congeneric Australian Masked-Owl T. novaehollandiae suggests that it probably occurs at low densities and therefore has a very small population which is likely to be declining owing to habitat loss. For these reasons it is classified as Vulnerable.

Family/Sub-family Tytonidae

Species name author Rothschild & Hartert, 1914

Taxonomic source(s) Sibley and Monroe (1990, 1993)

Identification 33 cm. Poorly known, medium-sized forest-dwelling owl. Identified by combination of dark upperparts, black tail with narrow yellowish-brown bars and buff underparts with large blackish spots. Similar spp. No other masked-owl in its range. Voice Undescribed.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

250-999

decreasing

1,900 km²

Yes

Range & population Tyto manusi is known only from two specimens from Manus in the Admiralty Islands of Papua New Guinea. Recent surveys have failed to locate this species and there are few if any convincing reports from local villagers^1,2,3. Tyto owls known only from subfossil bones on the adjacent islands of Mussau and New Ireland appear to have become extinct through unknown causes⁴. As with other Tyto owls, it may have been overlooked, but with further visits to Manus by birdwatchers and a continuing lack of records, its population may be smaller than 1,000 individuals.

Ecology: Tyto manusi is a rare owl of forest interior and has not been found in heavily degraded or swamp forest. It is poorly known but is assumed to have similar habits to Australian Masked-owl Tyto novaehollandiae. The latter is nocturnal, shy and secretive; it roosts in dense folliage, hollow tree trunks and caves. Australian Masked-owl feeds on small rodents and other small vertebrates and larger insects⁸. Manus Masked-owl is likely to have large territories, with a home-range size of between 0.04-1.8 km² per pair⁹.

Threats In 1987 80% of vegetation on Manus was estimated to be primary forest⁶. Large areas of lowland Manus are now logged or under logging concessions and in coastal areas the forest is being eroded by shifting cultivation. This is not a major threat but could be important for rare endemics such as Tyto manusi that are presumed to have tiny populations and distributions. Introduced mammalian predators, such as dogs and cats, may be implicated in the species's rarity but the brown tree snake Boiga irregularis, which has decimated birds on Guam, is thought to be native to Manus^5,2, and therefore might not pose a serious threat.

Conservation measures underway A large area of uninhabited forest including Mt Dremsel (719 m), has been identified as a very important area of terrestrial biodiversity⁷. CITES Appendix II.

Conservation measures proposed Continue surveying to locate the species on Manus. Study the taxonomy of T. manusi and T. novaehollandiae, and compare their ecology and biology⁸. Protect areas of suitable habitat.

References 1. G. Dutson pers. obs. (1997). 2. Dutson and Newman (1991). 3. D. Gibbs in litt. (1994). 4. Steadman and Kirch (1998). 5. R. Beck in litt. (1992). 6. Kula et al. (undated). 7. Beehler (1993). 8. König et al. (1999). 9. Higgens (1991). 10. A. Williams in litt. (2002).

Text account compilers Phil Benstead (BirdLife International), Guy Dutson (Birds Australia), Simon Mahood (BirdLife International), Andrew O'Brien (BirdLife International)

Contributors R Beck, David Gibbs, Mark Gregory, Steve Hamilton, Ann Williams

IUCN Red List evaluators Stuart Butchart (BirdLife International), Simon Mahood (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Tyto manusi. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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