 It has been calculated that around 98,000 hectares of native vegetation remains in the Sydney metropolitan area, about half of what is likely to have been existing at the time of European arrival.The fauna of the Sydney area is diverse and its urban area is home to variety of bird and insect species, and also a few bat, arachnid and amphibian species.Sydney is home to dozens of bird species, which mainly include the Australian white ibis, Australian raven, Australian magpie, crested pigeon, grey butcherbird, magpie lark, noisy miner, pied currawong, silver gull and willie wagtail, among others.