Tyto manusi Rothschild & Hartert, 1914

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Endemic Vulnerable

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorKaterina Tvardikova
Sourcehttp://pngbirds.myspecies.info/content/tyto-manusi

Range:

Manus I. (Admiralty Islands).

  • Clements, J. F., T. S. Schulenberg, M. J. Iliff, B.L. Sullivan, C. L. Wood, and D. Roberson. 2012. The eBird/Clements checklist of birds of the world: Version 6.7. Downloaded from http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist
Licensehttp://creativecommons.org/licenses/by-nc/3.0/
Rights holder/AuthorCornell Laboratory of Ornithology
SourceNo source database.

Population:

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.

Population Trend

Decreasing
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/22688464

Range Description:

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 villagers1,2,3. 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.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/106002149

Threats:

Major Threats

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.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/22688464

Habitat and Ecology:

Habitat and 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.

Systems

  • Terrestrial
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/106002149

Conservation Actions:

Conservation Actions

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.

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/22688464

IUCN Red List Assessment:
Red List Category

VU
Vulnerable

Red List Criteria

C2a(i);D1

Version

3.1

Year Assessed

2008

Assessor/s

BirdLife International

Reviewer/s

Mahood, S., Butchart, S.

Contributor/s

Gregory, M., Hamilton, S., Williams, A., Gibbs, D., Beck, R.

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.

History

  • 2004
    Vulnerable
  • 2000
    Data Deficient
  • 1996
    Vulnerable
  • 1994
    Vulnerable
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/106002149

Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/AuthorKaterina Tvardikova
Sourcehttp://pngbirds.myspecies.info/node/755

Population:

Population

Population estimate = 0.02-0.9 individuals/km2 x 1,500 km2 (estimated AOO from 1,800 km2 on basis of suitable habitat) = 30-1,350, i.e. best placed in band 250-999 (density range from congeneric species T. novaehollandiae).

Population Trend

Decreasing
Licensehttp://creativecommons.org/licenses/by-nc-sa/3.0/
Rights holder/Author© International Union for Conservation of Nature and Natural Resources
Sourcehttp://www.iucnredlist.org/apps/redlist/details/106002149
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