East Caroline Islands

Country/Territory Micronesia, Federated States of
Area 580 km2
Altitude 0 - 700m
Priority critical
Habitat loss moderate
Knowledge incomplete

General characteristics

This EBA includes the island states of Truk, Pohnpei and Kosrae, each separated from the other by c.500 km, with many tiny atolls between-but it excludes the state of Yap (EBA 191, c.1,500 km to the west though politically also part of the Federated States of Micronesia).

The native vegetation is rain forest, divisible into several different types including lowland and montane forest on the high islands, with cloud forest at the highest elevations on Pohnpei and Kosrae, and mangroves on sheltered coasts.

Restricted-range species

Most of the restricted-range species are forest birds occurring at all altitudes (though Rukia longirostra and R. ruki are typically confined to upper elevations), and several are able to utilize a variety of other habitats including plantations.

The islands have (or had) their own endemics-three species on Truk, five on Pohnpei and two (both extinct) on Kosrae-but they also share restricted-range species, making this a single EBA. Both Acrocephalus syrinx and Aplonis opaca are widespread within this EBA on atolls as well as on the high islands, and several other species occur more widely in other Micronesian EBAs (189-190).

Mottled Munia Lonchura hunsteini, a restricted-range species endemic to New Ireland, Papua New Guinea (EBA 195), was introduced to Pohnpei in the 1920s and is now abundant in the north and east of the island (Pratt et al. 1987).

Species IUCN Category
Caroline Ground-dove (Alopecoenas kubaryi) EN
Micronesian Imperial-pigeon (Ducula oceanica) VU
(Ptilinopus porphyraceus) NR
Caroline Swiftlet (Aerodramus inquietus) LC
Kosrae Crake (Zapornia monasa) EX
(Todiramphus cinnamominus) NR
Pohnpei Lorikeet (Trichoglossus rubiginosus) NT
Micronesian Myzomela (Myzomela rubratra) LC
Pohnpei Fantail (Rhipidura kubaryi) LC
Chuuk Flycatcher (Myiagra oceanica) LC
Pohnpei Flycatcher (Myiagra pluto) LC
Chuuk Monarch (Metabolus rugensis) EN
Caroline Reed-warbler (Acrocephalus syrinx) LC
Teardrop White-eye (Rukia ruki) EN
Long-billed White-eye (Rukia longirostra) NT
Citrine White-eye (Zosterops semperi) LC
(Zosterops cinereus) NR
Micronesian Starling (Aplonis opaca) LC
Pohnpei Starling (Aplonis pelzelni) CR
Kosrae Starling (Aplonis corvina) EX

Important Bird Areas (IBAs)
IBA Code Site Name Country
FSM001 Pohnpei Watershed Forest Reserve Micronesia, Federated States of
FSM007 Wiya Swiftlet Cave Micronesia, Federated States of
FSM008 Yela River Watershed Micronesia, Federated States of
FSM010 Mount Winipot / Tol South Micronesia, Federated States of
FSM011 Polle Island Micronesia, Federated States of
FSM012 Pata Island Micronesia, Federated States of
FSM013 Onei Island Micronesia, Federated States of
FSM015 South Weno Ridge Micronesia, Federated States of

Threat and conservation

Loss of forest is a serious problem in some parts of this EBA. For example, on Pohnpei, the lowland forests have been very disturbed and those in the uplands have been seriously affected too, mainly due to the growth of 'sakau' or 'kava' Piper methysticum as a major cash crop (B. Raynor in litt. 1995). On Truk, the only semi-original forest remaining is scattered in tiny remnants on the higher reaches of a few islands, most notably on Tol where the largest tract (0.68 km2) survives.

On Kosrae, however, where two species have become globally extinct, the forests are largely intact, especially in the interior, and it is assumed that the demise of its endemic birds was due to predation by introduced rats (Greenway 1967). Alien species (including possible future introductions, e.g. brown tree snake Boiga irregularis: see Mariana Islands, EBA 189) remain one of the main threats to the birds of this tiny island EBA.

Several unique ecological sites have been identified by Engbring et al. (1990). In 1987 51 km2 were set aside on Pohnpei in the centre of the island as a watershed reserve and all mangrove forests on the island (55 km2) were established as a protected area (B. Raynor in litt. 1995).

Recommended citation
BirdLife International (2021) Endemic Bird Areas factsheet: East Caroline Islands. Downloaded from http://www.birdlife.org on 04/12/2021.