 The land crabs and seabirds are the most noticeable fauna on the island.Christmas Island has been identified by BirdLife International as both an Endemic Bird Area and an Important Bird Area because it supports five endemic species and five subspecies as well as over one percent of the world populations of five other seabirds.Twenty terrestrial and intertidal species of crab have been described here, of which thirteen are regarded as true land crabs, being dependent on the ocean only for larval development.