This is the largest of Anguilla's outer islands and is separated from the mainland at its northeast corner by a 500 metre wide channel. The island is low lying with a rocky, fractured limestone coast punctuated by four sandy beaches, the eastern beaches attracting breeding terns. There is a large pond on the west side and a complex of 4 ponds and lagoons. The ponds are lined in places by mangroves and low trees. The centre of the island is largely scrub stretching to the coastline of heavily fissured limestone and low rocky cliffs. The island is uninhabited although the windblown remains exist of a former tourism development in the east and a wide grassy, former airstrip in the centre. There are large numbers of goats on the island, part of a project managed by Anguilla's Department of Agriculture
At least 34 species have been recorded including 8 species of breeding seabird: Red-billed Tropicbird, Laughing Gull, Royal Tern (30 pairs), Sandwich Tern (80 pairs), Roseate Tern (420 pairs), Least Tern (65 pairs), Bridle Tern and Brown Noddy. The site holds the only Anguillian breeding population of Roseate Terns. The island is low lying with breeding seabirds present on low cliffs, bare areas of friable limestone and on sandy beaches and spits. Five small ponds and coastal lagoons attract herons, wildfowl and shorebirds including small breeding populations of White-cheeked Pintail, American Oyster Catcher, Black-necked Stilt, and Willet. Wilsons Plover may also breed. Only 5 species of landbird have been recorded including Common Ground Dove, Caribbean Elaenia and Yellow warbler.
Non-bird biodiversity: Scrub Island has populations of 5 terrestrial reptiles: the ground lizard Ameiva plei, Tree lizard Anolis gingivinus, the little dwarf gecko Sphaerodactylus parvus, Island dwarf gecko Sphaerodactylus sputator and Anguilla's only native snake the Anguillan racer Alsophis rijgersmaeri. There are reports of both the Endangered Green Turtle Chelonia Mydas and Critically Endangered Leatherback turtle Dermochelys coriacea nesting on the beaches although there is no recent data.
BirdLife International (2021) Important Bird Areas factsheet: Scrub Island. Downloaded from http://www.birdlife.org on 13/04/2021.