the california department of fish and wildlife's bair island ecological reserve consists of on the middle and outer islands, although the entire island group is managed by the refuge. bair island is an important ecological wetland, which provides critical habitat for a variety of species, including the endangered california clapper rail and the salt marsh harvest mouse, and is an important stop for birds on the pacific flyway. bair island is bisected by corkscrew slough, a major haul-out site for harbor seals ("phoca vitulina").