Situated in mountains to the north of La Réunion, the site is a plain sloping from the northern rim of the Cirque de Mafate northwards towards the town of Saint-Denis. A deep gorge formed by the Rivière Saint-Denis cuts into this plain, separating the Plaine des Chicots in the east from the Plaine d’Affouches in the west. The lower half (1,000–1,550 m) is covered by mixed montane forest, which is gradually replaced at higher altitude by forest dominated by the endemic Acacia heterophylla (‘tamarin des hauts’). Above 1,600 m, montane shrubland or bushland and thicket dominates, becoming very sparse near the summit of La Roche Ecrite (2,277 m). The trail across the Plaine des Chicots to La Roche Ecrite is much used for recreation. For many years the site has been stocked with exotic deer Cervus timorensis for hunting, and lower parts abutting the site (to the south) used for plantations of the exotic conifer Cryptomeria japonica.
See Box and Table 2 for key species. The site is the only breeding area for Coracina newtoni (entire known population, 120–150 pairs) and supports populations of all the other native, forest-living birds of La Réunion, together with important colonies of Puffinus lherminieri. Up to five pairs of Circus maillardi were present in 1998.
Non-bird biodiversity: Endemic plant communities: rich forest with many endemic plants. Lepidoptera: several endemic moth species. Reptiles: Phelsuma borbonica (endemic).
BirdLife International (2020) Important Bird Areas factsheet: Plaine des Chicots - Plaine d'Affouches. Downloaded from http://www.birdlife.org on 10/07/2020.