Australia and its offshore islands and territories have 898 recorded bird species as of 2014.[1] Of the recorded birds, 165 are considered vagrant or accidental visitors, of the remainder over 45% are classified as Australian endemics: found nowhere else on earth.[1] It has been suggested that up to 10% of Australian bird species may go extinct by the year 2100 as a result of climate change.[2]
Australian species range from the tiny 8 cm (3.1 in) weebill to the huge, flightless emu. Many species of Australian birds will immediately seem familiar to visitors from the Northern Hemisphere: Australian wrens look and act much like northern wrens, and Australian robins seem to be close relatives of the northern robins. However, the majority of Australian passerines are descended from the ancestors of the crow family, and the close resemblance is misleading: the cause is not genetic relatedness but convergent evolution.
For example, almost any land habitat offers a nice home for a small bird that specialises in finding small insects: the form best fitted to that task is one with long legs for agility and obstacle clearance, moderately-sized wings optimised for quick, short flights, and a large, upright tail for rapid changes of direction. In consequence, the unrelated birds that fill that role in the Americas and in Australia look and act as though they are close relatives.
Australian birds which show convergent evolution with Northern Hemisphere species:
Australia Birds, a portable folding guide authored by zoologist James Kavanagh, features 140 of the most familiar species. Part of a four title series on Australia flora & fauna featuring ecoregions and major bird spotting sites around the country.
Finding Australian Birds, authored by Tim Dolby and Rohan Clarke (2014), features the best places in Australia for finding birds.
The Action Plan for Australian Birds 2000, Garnett, Stephen T.; & Crowley, Gabriel M., Environment Australia, Canberra, 2000 ISBN0-642-54683-5, a comprehensive survey of the conservation status of Australian species, with costed conservation and recovery strategies.
The country does not suffer from several Apicomplexan parasites found throughout the rest of the world.[5]: 14, 36 Several species of both avian haemoproteids and avian Plasmodium spp. are absent here.[5]: 14, 36
