|Scientific Name:||Tyto manusi|
|Species Authority:||Rothschild & Hartert, 1914|
|Red List Category & Criteria:||Vulnerable C2a(i);D1 ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Beck, R., Dutson, G., Gibbs, D., Gregory, M., Gregory, P., Hamilton, S. & Williams, A.|
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. Clarification of its likely subpopulation structure may lead to its uplisting to Endangered in the near future
Tyto manusi is known only from two historic specimens from Manus in the Admiralty Islands of Papua New Guinea. There are no records of the species since 1934 (P. Gregory in litt. 2012) as recent surveys have failed to locate this species and there are few if any convincing reports from local villagers (Dutson and Newman 1991, D. Gibbs in litt. 1994, G. Dutson pers. obs. 1997). Tyto owls known only from subfossil bones on the adjacent islands of Mussau and New Ireland appear to have become extinct through unknown causes (Steadman and Kirch 1998). 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.
Native:Papua New Guinea
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.|
|Habitat and Ecology:||Tyto manusi is a rare owl of forest interior and has not been found in heavily degraded or swamp forest, although as it is only known from two specimens, it may have wider habitat tolerances. 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 insects (König et al. 1999). Manus Masked-owl is likely to have large territories, with a home-range size of between 0.04-1.8 km2 per pair (Higgins 1991).|
|Major Threat(s):||In 1987, 80% of vegetation on Manus was estimated to be primary forest (Kula et al. undated). 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 (Dutson and Newman 1991, R. Beck in litt. 1992), and therefore might not pose a serious threat.|
Conservation Actions Underway
CITES Appendix II. A large area of uninhabited forest including Mt Dremsel (719 m), has been identified as a very important area of terrestrial biodiversity (Beehler 1993).
Conservation Actions Proposed
Continue surveying to locate the species on Manus. Study the taxonomy of T. manusi and T. novaehollandiae, and compare their ecology and biology (König et al. 1999). Protect areas of suitable habitat.
Beehler, B. M. 1993. Biodiversity and conservation of the warm-blooded vertebrates of Papua New Guinea. In: Beehler, B.M. (ed.), Papua New Guinea - conservation needs assessment, pp. 77-121. Biodiversity Support Program, Washington, DC.
Dutson, G. C. L.; Newman, J. L. 1991. Observations on the Superb Pitta Pitta superba and other Manus endemics. Bird Conservation International 1: 215-222.
Higgins, P. J. 1999. Handbook of Australian, New Zealand and Antarctic birds: parrots to dollarbirds. Oxford University Press, Oxford, U.K.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
König, C.; Weick, F.; Becking, J.-H. 1999. Owls: a guide to the owls of the world. Pica Press, Robertsbridge, U.K.
Steadman, D. W.; Kirch, P. V. 1998. Biogeography and prehistoric exploitation of birds in the Mussau islands, Bismarck Archipelago, Papua New Guinea. Emu 98: 13-22.
|Citation:||BirdLife International 2012. Tyto manusi. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 24 May 2013.|
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