This IBA is situated on slopes of the highest mountain of the northern cape of Mahé. A short, dense shrub woodland vegetation is dominated by introduced species, mainly Tabebuia pallida, Cinnamomum verum and Chrysobalanus icaco. Scattered taller trees include Paraserianthes falcataria, Sandoricum indicum and Pterocarpus indicus, while some endemic species such as Deckenia nobilis, Phoenicophorium borsigianum and Paragenipa wrightii are also found. There are some rocky areas with large boulders and caves. The woodland was exploited for the cinnamon industry, firewood and timber until 20–30 years ago. Only some selective cutting now occurs.
See Box and Table 2 for key species. The site holds the largest colony of Collocalia elaphra known in Seychelles, comprising 600–800 pairs (March 1997 estimate). The colony is located on the roof of a large cave of difficult access, at c.10 m from the ground, and consists of a single mass of nests between 6–8 m in length. A few pairs of Falco araea are also present, as well as the three more common endemics Alectroenas pulcherrima, Hypsipetes crassirostris and Nectarinia dussumieri. Streptopelia picturata picturata also occurs, as well as Phaethon lepturus and Gygis alba which nest at low densities in trees and rocks.
Non-bird biodiversity: Small numbers of endemic reptiles and amphibians are present.
BirdLife International (2020) Important Bird Areas factsheet: Montagne Glacis - When She Comes. Downloaded from http://www.birdlife.org on 09/08/2020.