The republic of Palau consists of c.340 islands and islets, of which eight are inhabited. Some islands are of volcanic origin-Babeldaob (the highest island at 218 m and by far the largest, representing more than 75% of Palau-s total land area), parts of Koror and a few small islands in the Koror vicinity-while all others (including the Rock Islands, Peleliu and Angaur) are of more recent limestone formation. Six tiny remote islands, 600 km south-west of the main archipelago (the Southwest Islands), are politically part of Palau, but are not included in the EBA as they do not harbour any restricted-range species.

Dense, tropical, broadleaf forests cover most volcanic and virtually all limestone islands, with the notable exception of Babeldaob, where much of the original forest has been lost and replaced by savanna and grassland, although extensive mangrove forests still remain in protected coastal areas.

All the restricted-range species are inhabitants of forest and many also forage in mangroves. Most species occur through all of the islands; the exceptions being Gallicolumba canifrons (very rare on Babeldaob, commoner on the limestone islands) and Megazosterops palauensis (apparently restricted to Peleliu and Ngeruktabel). Several species occur more widely in other Micronesian EBAs (189, 191, 192).

None of the endemics is currently classified as threatened, but all these species are potentially at risk from introduction of alien forms. Possible future introduction of brown tree snake Boiga irregularis, which caused the extinction of many bird species on Guam (see Mariana Islands, EBA 189), is a particular cause for concern, especially to the two species which have the most restricted ranges, and which are consequently classified as Near Threatened.

With the decline in authority of local chiefs, and increasing use of guns and speedboats, certain species of bird, e.g. columbids, seabirds and, notably, Megapodius laperouse, have been subject to considerable hunting pressure. Today, however, guns are outlawed, pigeon populations appear to be recovering and nearly all birds on Palau are fully protected by local law. Although densities of Megapodius laperouse are low throughout Palau (a population estimate for all islands excluding Kayangel of less than 500 was made in 1991), numbers appear relatively stable with the greatest threat now being tourist use of rock island beaches where the birds nest (Engbring 1988, 1992, H. D. Pratt in litt. 1995).

Loss of habitat has adversely affected some birds, particularly on Koror and Babeldaob, which are becoming rapidly built up; on Babeldaob extensive areas of native vegetation are burned each year, increasing the size of barren savannas (Engbring 1988). However, the forests on this island grow on very poor soil and harbour few birds compared to the rock island forests (H. D. Pratt in litt. 1995), which are more important for the conservation of restricted-range bird species.

Several subspecies which are endemic to Palau qualify as threatened. These include Palau Nicobar Pigeon Caloenas nicobarica pelewensis (a subspecies of a widespread globally Near Threatened species), which is conservatively estimated to number c.700 individuals and is most common on the Rock Islands; Palau White-breasted Woodswallow Artamus leucorhynchus pelewensis, which may number fewer than 100 birds and is found almost exclusively on the upper savannas of Babeldaob; and Palau Blue-faced Parrotfinch Erythrura trichoa pelewensis, which is virtually restricted to Casuarina groves along beaches of the Rock Islands and is estimated to number just over 1,000 individuals (Engbring 1992, H. D. Pratt in litt. 1994, 1995).

The EBA's single protected area covers the Ngerukeuid Islands; it is an important pristine reserve where most of the restricted-range species occur (Wiles and Conry 1990). Establishment of other ecological reserves has been recommended, including the protection of forested tracts on Peleliu and Babeldaob, and a Rock Island Reserve covering the largest islands of Ngeruktabel and Mecherchar (Engbring 1992). In a recent conservation education campaign (RARE/Palau Conservation Society) Ptilinopus pelewensis was chosen as Palau's national bird.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Palau. Downloaded from https://datazone.birdlife.org/eba/factsheet/191 on 23/11/2024.