Current view: Text account
Site description (2001 baseline):
Site location and context
This site occupies the north-western and central part of Mahé (c.20% of the whole island) and contains Morne Seychellois National Park (3,090 ha), which includes the highest mountain of Seychelles (914 m). Its steep slopes are covered with dense secondary forests and shrub woodland, interrupted by impressive cliffs and granite boulders (
glacis). This IBA also includes the mountainous area to the south-east, between the former Satellite Tracking Station (New Savy), Cascade, Montagne Planeau, Grand Bois, Castor, Varigault and Mont Sébert. This area lies outside the national park, but a project exists to partially protect it. The adjacent areas of La Misère and Cascade, also included, are mainly occupied by man-modified habitats, such as residential areas, orchards, small-scale agriculture and cattle farms, tea plantations, roads, powerlines and other infrastructure. Forests of low and intermediate altitudes are dominated by exotic, invasive trees (mainly
Cinnamomum verum,
Paraserianthes falcataria and
Alstonia macrophylla), shrubs (the invasive exotic
Chrysobalanus icaco), and huge granite boulders but, above 600 m in the Morne Seychellois National Park, stands of primary moist forest with few exotics still remain. Endemic species include
Medusagyne oppositifolia and
Vateriopsis sechellarum (both very rare),
Dillenia ferruginea and
Northea hornei (more common),
Phoenicophorium borsigianum and
Nephrosperma vanhoutteanum,
Erythroxylum sechellarum,
Nepenthes pervillei and
Secamone schimperianus. During the nineteenth and the first half of the twentieth centuries extensive exploitation of timber and cinnamon production took place. Present human activities (forestry, nature conservation/research, tourism and a little tea cultivation), are limited to less than 10 % of the total area of the IBA.
See Box and Table 2 for key species. This site contains virtually the world population of
Otus insularis (90–180 pairs). The La Misère, Haut Barbarons, and Cascade areas are the only three known significant breeding sites on Mahé for
Zosterops modestus (c.12 pairs plus helpers, with about 10–15 birds at each site). These hold about 10% of the world population for this species. The IBA also holds 60–120 pairs of
Falco araea (about 25% of the world population) and
Collocalia elaphra, of which there are probably several hundreds of pairs, nesting in as yet undiscovered colonies. One cave near Le Niol, apparently occupied in the past, is now deserted. Due to its large size, the site is also of great importance for
Alectroenas pulcherrima (>350 pairs),
Hypsipetes crassirostris (1,700–2,400 pairs) and
Nectarinia dussumieri (1,500–2,300 pairs). Other species of interest include
Streptopelia picturata picturata,
Phaethon lepturus (at least 200 pairs) and
Gygis alba.
Butorides striatus and
Gallinula chloropus occur in ponds at low altitude.
Non-bird biodiversity: Four species of frogs and six species of caecilians endemic to Seychelles occur. The IBA is the main stronghold for the rare endemic tiger chameleon Chamaeleo tigris and contains important populations of the endemic snakes Lamprophis geometricus and Lycognathophis seychellensis. Several endemic skinks and geckos are also present. The site also hosts small numbers of the bat Coleura seychellensis seychellensis (CR) and large numbers of the bat Pteropus seychellensis.
Pressure/threats to key biodiversity
Revision of boundaries of the present National Park may result in the inclusion of the mountainous areas to the south, in the Central Highlands. A buffer zone may also be added to the existing park. Current research and monitoring activities in the park are limited due to difficulties of access. A management plan has recently been produced for the park. Main threats include exotic plants replacing native flora and infringement of the park boundaries by housing development. Predation by introduced rats, domestic cats and birds (e.g.
Tyto alba) of the native bird fauna appears to be a serious problem. In particular, nest-predation by rats
Rattus rattus and mynah-birds
Acridotheres tristis is considered a major threat to the survival of the
Zosterops modestus population and, possibly, of
Otus insularis. Planned housing and road development projects in Mahé Central Highlands may pose a significant threat, if confirmed. Illegal cutting of threatened endemic plants for food (
Deckenia nobilis) and traditional medicinal use may also become a problem. Conservation measures are needed for
Zosterops modestus in the residential La Misère and Cascade areas. These include control of insecticide use, public awareness, limitation of housing development and tree-felling and close monitoring of habitat and of the
Zosterops population.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Mahé highlands and surrounding areas (Seychelles). Downloaded from
https://datazone.birdlife.org/site/factsheet/mahé-highlands-and-surrounding-areas-iba-seychelles on 22/11/2024.
