Upland regions included within this EBA are the Snow mountains (Charles Louis, Weyland and Nassau ranges), Star mountains (Oranje, Star, Victor Emanuel and Hindenburg ranges), Central Highlands (Schrader, Muller and Central ranges), Eastern Highlands (Bismarck, Kubor and Kratke ranges) and the South-east Highlands (Wharton, Herzog and Owen Stanley ranges). These mountain ranges run unbroken from the isthmus of the Vogelkop (EBA 172) in the Indonesian province of Irian Jaya to Milne Bay in Papua New Guinea. Because there are no passes below 1,500 m, lowland species which occur on either side of the mountains are isolated from one another, and separate lowland EBAs are recognized: EBA176 to the north and EBA179 to the south. The lower limit of the present EBA has been defined as the 1,000 m contour, although some of the restricted-range species may occur below this and there may be some overlap with the distributions of restricted-range species from the adjacent lowland EBAs.

Four different vegetation zones occur in the Papuan mountains: lower montane rain forest (c.500-2,500 m) where the oak Castanopsis acuminatissima is predominant; upper montane forest (c.1,500-3,000 m) where the southern beech Nothofagus predominates and the forest is often thick with moss; high mountain forest (c.2,500-3,900 m) containing trees of reduced stature, and where conifers (Podocarpaceae) and myrtle (Myrtaceae) increase in importance; and, lastly, alpine shrubbery and grassland above the treeline (Coates 1985, Beehler et al. 1986).

This EBA has the second most restricted-range species of all the EBAs in the south-east Asian island region, as well as a very distinct avifauna, including nine endemic genera: four genera of birds-of-paradise-Loboparadisea, Cnemophilus, Macgregoria and Pteridophora-together with Anurophasis, Androphobus, Eulacestoma, Oreornis and Oreostruthus. Most of the restricted-range species occur in forested habitats and these species can be divided into four groups according to the vegetation types with which they largely associate: lower montane forest, lower-upper montane forest, upper montane-high mountain forest, and high mountain forest. Additionally, six species occur in grasslands only. Because there is overlap between the distributions of birds which have been assigned to these different groups, all restricted-range species occurring in these mountains have been included within a single EBA (contra ICBP 1992).

The long central mountain ranges of this enormous EBA are a formidable barrier to dispersal and many species are thus limited in their distributions just to certain ranges, e.g. nine species are endemic to the Snow-Star mountains and eight to the Central-South-east Highlands. Several species are very patchily distributed throughout the EBA and it has been difficult to determine which of these genuinely qualify as having ranges of less than 50,000 km²; Loboparadisea sericea, for example, occurs along the length of the Central Ranges, but is often uncommon or absent from seemingly appropriate habitats for reasons unknown (but possibly related to the presence or absence of important food plants: Beehler et al. 1986, Coates 1990)-or it may simply be overlooked because it is unobtrusive and inhabits very rugged and rarely visited terrain (K. D. Bishop in litt. 1994, 1996).

In general this region is relatively little studied ornithologically and therefore several of the species which appear to be very scarce and/or have disjunct distributions could in reality be more common or have more contiguous ranges. For example, Androphobus viridis was formerly known from the Snow mountains only, but since 1990 there have been at least four possible sight records from the Ambua area, near Tari, in the Eastern Highlands, and it may also have been recorded from the Star mountains in 1992. Melanocharis arfakiana is known only from one specimen in this EBA (collected in 1933) from the upper Angabunga river in the South-east Highlands, but sightings have been reported from near Tabuli in the Central Highlands, and it could therefore occur more widely. Petroica archboldi is known only from the highest peaks of the Snow mountains and there are no recent records.

The montane rain forests and alpine grasslands of this EBA remain largely undisturbed-even untouched-owing to their very large extent and geographical isolation, combined with the traditional lifestyle and low population density of local people. However, logging (both from large-scale commercial operators and from smaller-scale initiatives which use walkabout sawmills), mining and road-building (e.g. the Trans-Irian Highway from Jayapura to Merauke) are significant local threats, and forest encroachment, illicit logging and wildlife harvesting need to be monitored and controlled (Sujatnika et al. 1995, P. Gregory in litt. 1994, K. D. Bishop in litt. 1996).

Just five species are currently classified as threatened. Melidectes princeps is known from only a few mountains in the Eastern Highlands, where it is thinly distributed and suffers disturbance to its limited habitat, which is patchy and dissected. For some species, loss of habitat is exacerbated by hunting, e.g. Macgregoria pulchra, which is a popular quarry species, being unwary and site-faithful and therefore easy to kill, and Astrapia mayeri and Paradisaea rudolphi, which are both hunted for their tail plumes used in local costumes. Archboldia papuensis is very patchily distributed, with western and eastern populations appearing to be widely separated; it is generally rare and locally threatened by timber operations. Salvadori's Teal Salvadorina waigiuensis, Pesquet's Parrot Psittrichas fulgidus and Black Sicklebill Epimachus fastuosus are widespread threatened species (all classified as Vulnerable) which also occur in this EBA; all are affected by hunting and S. waigiuensis may also suffer locally from the pollution of streams and lakes.

Four restricted-range species are considered Data Deficient because of uncertainties associated with their range size (which may or may not be very small) and lack of records (see 'Restricted-range species', above).

Extensive areas of the habitats of this EBA are contained within three large protected areas on the Irian Jaya side: Gunung Lorentz Nature Reserve (in the Snow mountains, 21,500 km²), which is Indonesia's largest protected area; Jayawijaya Wildlife Sanctuary (Star mountains, 8,000 km²); and the Enarotali Nature Reserve (Weyland mountains, 3,000 km²). However, the montane forests in this last reserve have been degraded, and land around Lake Paniai, at the reserve's centre, is heavily populated; consideration should be given to establishing another reserve to cover a spectrum of habitat types and endemic flora and fauna, and to protect the water catchment (Sujatnika et al. 1995). There are proposals to establish a national park (possibly a World Heritage Site) at Lorentz covering 14,300 km².

In Papua New Guinea, Mt Scorpion (Star mountains), Doma Peaks and Mt Giluwe (Central Highlands), Crater Mountain (Eastern Highlands), Mt Albert Edward and Mt Suckling (South-east Highlands) have been identified as important areas for terrestrial biodiversity by Beehler (1993).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Central Papuan mountains. Downloaded from https://datazone.birdlife.org/eba/factsheet/178 on 22/11/2024.