The Admiralty Islands, politically part of Papua New Guinea, are often grouped with the St Matthias Islands (EBA 194) and the larger islands of New Britain and New Ireland (EBA 195) into the Bismarck archipelago, but are here treated as an EBA in their own right. The much smaller islands surrounding the main island of Manus also harbour restricted-range species and so are included within the EBA.

The hilly terrain of Manus (reaching 719 m on Mt Dremsel) is covered in rain forest up to its maximum altitude, with an estimated 80% of vegetation being primary forest in 1987 (Kula et al. undated).

All the restricted-range species occur in forest, and a number occur in secondary growth. There are no reported avifaunal changes with altitude.

Of the six species confined to this EBA, four are endemic to Manus, with Monarcha infelix and Rhipidura semirubra occurring on some of the surrounding islands (there are records from Lou, Fedarb, San Miguel, Rambutyo, Pak and Tong). Several of the more-widespread restricted-range species are small-island birds and occur in other Papuan island and Melanesian EBAs, but do not show clear affinities to any single EBA.

Manus has no protected areas, and the vulnerability of the island's wildlife was exposed when it was proposed to build a satellite launch site there, but this project is currently shelved (I. Burrows in litt. 1994, P. Gregory in litt. 1994). Nevertheless, the forest on Manus is being eroded by shifting cultivation, with a number of villages using portable sawmills, taking selected trees for domestic use and for the sale of planks (Buckingham et al. 1995). Although this forest loss is still on a relatively small scale and mainly in coastal areas (and is therefore unlikely to be a major threat), three of the Manus endemics are very rare and are classified as threatened on account of their (presumed) tiny populations and distributions.

For example, a tentative population estimate of 1,000 calling birds was made for Pitta superba in 1990, but, if the species has specific habitat preferences, this may be an overestimate (Dutson and Newman 1991). Observations in 1994 indicate that it may survive in secondary growth and overgrown gardens, and that bamboo could be an important feature of its habitat requirements (D. Gibbs in litt. 1994), perhaps accounting for its apparent rather patchy distribution (P. Gregory in litt. 1996).

As with all small islands, introduced mammalian predators may be implicated in the rarity of the Manus birds, but that island's interior forests are little known and Tyto manusi and Rhipidura semirubra may simply be overlooked; neither have been recorded there recently, though R. semirubra may be common on the surrounding islands (G. C. L. Dutson in litt. 1996, D. Gibbs in litt. 1996). Islanders say that R. semirubra survives on the tiny island of Tong because of the absence of Philemon albitorques, which may have undergone a population explosion (detrimental to R. semirubra) associated with human colonization and clearance on Manus (D. Gibbs in litt. 1994).

A large segment of uninhabited interior forest on Manus, including Mt Dremsel, has been identified as a very important area of terrestrial biodiversity in Papua New Guinea by Beehler (1993).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Admiralty Islands. Downloaded from https://datazone.birdlife.org/eba/factsheet/193 on 23/11/2024.