Fauna of Australia in Australia, feeding on sea grass in coastal areas. The destruction of sea grass beds is a threat to the survival of this species. Eleven species of seal—family Pinnipedia—live off the southern coast. Australia and its territories are home to around 800 species of bird; 45% of these are endemic to Australia. The fossil record of birds in Australia is patchy; however, there are records of the ancestors of contemporary species as early as the Late Oligocene. Birds with a Gondwanan history include the flightless ratites (the emu and southern cassowary), megapodes (the malleefowl and Australian brush-turkey), and a huge
Flightless bird requirement for flightlessness. The kiwi does not exhibit gigantism, along with tinamous, even though they coexisted with the moa and rhea that both exhibit gigantism. This could be the result of different ancestral flighted birds arrival or because of competitive exclusion. The first flightless bird to arrive in each environment utilized the large flightless herbivore or omnivore niche, forcing the later arrivals to remain smaller. In environments where flightless birds are not present, it is possible that after the K/T Boundary there were no niches for them to fill. They were pushed out by other herbivorous mammals. New Zealand had