Aride (68.3 ha) is the most northerly of the granitic islands, lying 9 km north of Praslin and 45 km north-east of Mahé. The site also includes 105 ha of coastal marine habitat. A ridge of Precambrian granite, rising to 135 m, dominates a small plateau of 9 ha. There is a single beach 800 m long on the southern side of the island while the rest of the coastline is composed of cliffs and rocky shore. The island is densely covered with mixed native woodland dominated by Pisonia grandis, Ficus lutea and F. reflexa. Granite outcrops and open glades are abundant on the hill, where there are also smaller areas of Euphorbia pyrifolia scrub. A young, managed woodland, replanted with indigenous species (Callophyllum inophyllum, Terminalia catappa, Morinda citrifolia, etc.), and a small wetland, are present on the plateau. Human activities are limited to nature conservation, research and ecotourism (day visits and confined to main paths only). Most of the former coconut plantation has been progressively eliminated and the only remaining agricultural activity is restricted to a small garden for resident staff. Coral reefs surround the island.
See Box and Table 2 for key species. With approximately one million breeding seabirds of 10 species, Aride island holds one of the most important seabird colonies of the Indian Ocean. In addition to the tern species listed below, 71–89 pairs Sterna anaethetus also breed. Aride also hosts the largest known population in Seychelles of Puffinus lherminieri nicolae and is the most northerly breeding site for Phaethon rubricauda (3–5 pairs). Important numbers of Puffinus pacificus also occur from September to March. Seabird numbers are largest during the south-east monsoon, from May to October, the breeding season for many species. However, Phaethon lepturus, Gygis alba, Puffinus lherminieri and Sterna anaethetus may nest all year-round. Mixed, non-breeding flocks of Fregata minor and F. ariel are regularly seen roosting or soaring over the island (up to 4,600 birds between November and February). Landbirds include Acrocephalus sechellensis, originating from 29 birds introduced from Cousin in 1988. With a minimum of 1,600 birds present in 1997, the majority of the world population now occurs on Aride. Several attempts to re-establish a breeding population of Copsychus sechellarum have not so far succeeded (one pair still present in 2001). Nectarinia dussumieri (min. 49 birds) and Alectroenas pulcherrima (min. three pairs) have recolonized the island naturally. Streptopelia picturata picturata (200–400 birds) and Gallinula chloropus (200–400 birds) are also present.
Non-bird biodiversity: There are eight resident reptile species, of which seven are endemic (including Mabuya wrightii and M. seychellensis at extremely high densities). Among the large invertebrate fauna, the whip scorpion Phrynicus scaber is present in good numbers. The turtles Eretmochelys imbricata (CR) and, occasionally, Chelonia mydas (EN) nest on the beach. Of the 100 vascular plants recorded on the island, Rothmannia annae is now restricted to Aride, as may be the Peponium sp. (taxonomy uncertain).
BirdLife International (2019) Important Bird Areas factsheet: Aride Island Special Reserve. Downloaded from http://www.birdlife.org on 21/11/2019.