 The islands have been identified by BirdLife International as an Important Bird Area because they support very large numbers of nesting seabirds.Nineteen species of birds have been recorded as breeding on Heard Island and the McDonald Islands, although recent volcanic activity at the McDonald Islands in the last decade is likely to have reduced vegetated and un-vegetated nesting areas.Penguins are by far the most abundant birds on the islands, with four breeding species present, comprising king, gentoo, macaroni and eastern rockhopper penguins.