The site comprises a steep-sided valley in the dry, north-western lowlands between St-Denis and La Possession, together with the lowest part of the Ravine à Jacques, 1 km to the north-east. It contains a few habitations at the river mouths, a tourist centre and a military firing range, but around 40% of the site is protected, as it is one of the last sites on La Réunion where dry evergreen lowland forest survives. Other major habitats are secondary grassland and exotic thickets; small areas of cliff and rocky shore also occur.
See Box and Table 2 for key species. The site supports a high density of breeding Circus maillardi (5–10 pairs in 1997) and two of the largest known colonies of Collocalia francica (at least two large colonies totalling c.1,000 pairs in 1998) and all the other forest-living native birds of La Réunion except Coracina newtoni. Up to 100 pairs each of three seabird species (Puffinus pacificus, P. lherminieri and Phaethon lepturus) nest, but their populations are not globally significant.
Non-bird biodiversity: Dry evergreen lowland forest is the most threatened vegetation-type on the island, and supports many endemic plants.
BirdLife International (2018) Important Bird Areas factsheet: Ravine de la Grande Chaloupe. Downloaded from http://www.birdlife.org on 19/11/2018.