Site description (2006 baseline)
This site is the largest remaining forest area on Montserrat, forming a single, almost continuous block of hill forest in the centre of the island. A series of small, steep streams (known locally as ghauts) radiate from central ridges. The boundary goes beyond the forest reserve to include areas where the Montserrat Oriole is found. There is a transitionfrom tropical deciduous forest in the drier lowlands (especially on the eastern and north-eastern sides), through semi-deciduous and evergreen tropical forest at higher altitudes to elfin forest on the summit of Katy Hill. The majority of the forest is secondary, having been cleared foragriculture during the plantation era. The frequent passage of hurricanes ensures that there is a range of successional stages. Most of the area is steep and pathless. Apart from small agricultural and banana plots around the periphery, the area is little used or visited by humans. It forms the main water catchment for the inhabited area of the island, and recently several trails have been cleared to allow tourists to explore the area.
The vast majority of the world population (thought to be 200 to 400 pairs) of the Critically Threatened Montserrat Oriole is resident in the Centre Hills. The Vulnerable Forest Thrush also occurs at relatively high densities throughout, and this site may well be the world stronghold for the species. The Near-threatened Bridled Quail-dove is also common. Seven other restricted-range species of the Lesser Antillean EBA are relatively common: the Purple-throated Carib, Greenthroated Carib, Antillean Crested Hummingbird, Brown Trembler, Scaly-breasted Thrasher, Pearly-eyed Thrasher and the Lesser Antillean Bullfinch. The Centre Hills is the major site on the island for most of these species. The main exceptions to this are the Green-throated Carib and the Lesser Antillean Bullfinch, which are more common in the surrounding lowlands. Pearly-eyed Thrashers and Antillean Crested Hummingbirds are abundant throughout Montserrat in all habitats. Brown Tremblers, Montserrat Orioles and Bridled Quail-doves are confined to the Centre Hills and Roche's Forest (MS003). Point count monitoring carried out between 1997 and 2003 indicates that populations of most species have increased in recent years. Exceptions to this are the Montserrat Oriole and Brown Trembler, both of which showed indications of a population decline during the monitoring period. Most of the key species are found in all forest types in the Centre Hills. The Purple-throated Carib reaches highest densities in dry forest, and the Pearly-eyed Thrasher is most abundant in lowland areas. The Montserrat Oriole occurs primarily in mesic and wet forest, and is scarce in dry forest. At around 19 birds ha-1, densities of the Pearlyeyed Thrasher are among the highest in its range (Arendt, in press).
Non-bird biodiversity: As by far the largest area under broadly natural vegetation cover in Montserrat, the Centre Hills is the stronghold for much native wildlife, including many of the island's endemic species and sub-species. The Montserrat galliwasp Diploglossus montisserrati (CR) has only ever been recorded from the Cassava Ghaut area of the Centre Hills. The mountain chicken Leptodactylus fallax occurs relatively abundantly and is absent elsewhere on the island (this, the second largest frog in the world, is found only in Dominica and Montserrat). The endemic Montserrat anole Anolis lividus (Iguanidae) is common in the Centre Hills, and through many parts of the island. The Montserrat ameiva Ameiva pluvianotata pluvianotata (Teiidae) and Southern Leeward dwarf gecko Sphaerodactylus fantasticus ligniservulus (Gekkonidae) are endemic sub-species. The former is found in the edges of the Centre Hills, but is more common in the lowlands. The latter is abundant in the Centre Hills and throughout Montserrat. The endemic subspecies Montserrat black snake Alsophis antillensis manselli (Colubridae) is relatively common in the Centre Hills, but rarer in inhabited areas of Montserrat. The endemic subspecies Montserrat blind worm snake Typhlops monastus monastus (Typhlopidae) occurs in the Centre Hills, and at some other sites in Montserrat, but its status is poorly known.As a generalisation, bat diversity on Montserrat is thought to be highest in the southern and western ghauts of the Centre Hills (Soldier Ghaut to Sappit Spring) (S Pedersen, personal communication). Tadarida brasiliensis (Nearthreatened) is probably present in this IBA, and is believed to be common and widespread throughout Montserrat, though under-recorded (ibid.). The endemic sub-species Ardops nichollsi montserrratensis is common on Montserrat, but specialises in smaller, native fruits, and although widespread, its population is likely to be concentrated in higher-altitude native forests. Hence, the Centre Hills are probably an important stronghold on the island. Similarly, the nectarivorous Monophyllus plethodon (Near-threatened) is probably most common in the Centre Hills, but widespread elsewhere in Montserrat.The insect fauna of Montserrat has been little studied, but was the subject of a major research project in 2000-2003, which focused on the Centre Hills. Extremely high levels of endemism are apparent. For example, several hundred to a thousand beetle species are thought to be present in the IBA, of which approximately 30% are previously undescribed, and 10% are endemic. The Centre Hills may be home to the world's smallest Cerambycid (longhorn beetle). An enormous scarab beetle larva found in dead logs in the Centre Hills awaits identification, but is likely to be a new genus; it is certainly endemic and may be the largest insect in the UK and its Territories. Among other taxa, the Centre Hills holds an undescribed endemic sawfly, an undescribed endemic long-horned grasshopper, and several undescribed flies that may be endemic. Although sampling has not been sufficiently widespread to determine the Montserratian range of these species, it is inevitable that the Centre Hills is the most important site on the island, since it is the largest area of natural vegetation and covers a large altitudinal range. It is important for the following globally threatened plant species: the red cedar Cedrela odorata (VU), lignum vitae Guaiacum officinale (EN), Brazilian mahogany Sweitenia macrophylla (VU) and American mahogany Swieteniamahagoni (EN).
BirdLife International (2023) Important Bird Area factsheet: Centre Hills. Downloaded from http://datazone.birdlife.org/site/factsheet/centre-hills-iba-montserrat-(to-uk) on 02/12/2023.