The plateau area contains large phosphate deposits that almost completely inhibit any natural growth useful for subsistence or commerce. Large areas of scrub and creeper, with occasional coconut and tamanu trees, grow in this region. On the coastal belt, coconut palms and pandanus (a type of screw pine) thrive. Some hibiscus, frangipani, and other tropical flowers grow, but they do not abound here as on other Pacific islands. Bird life is not plentiful, although noddies, terns, and frigate birds frequent the island. There are no indigenous land animals; however, hogs and poultry were introduced many years ago. Fish life is abundant in the seas encircling Nauru and good catches of tuna and bonito are taken.