To identify changes in the dominance of broad groupings of bird species associated with the urbanisation of Sydney, records from the Australian Museum Ornithology Collection database and the Birds Australia Atlas Database were analysed. This historical comparison suggests that parrots, large honeyeaters, large carnivores and exotics are the species that have historically been the most tolerant of urbanisation. The Birds in Backyards project is a research, education and conservation program directed towards the birds that live where people live. Part of the project involves the facilitation of backyard bird surveys conducted by volunteers who enter their survey data on line. This steadily growing database can be used to examine the relationships between common urban birds, both amongst each other and with human-generated habitat variables. It can also be used to identify local variation in bird communities and has potential for monitoring temporal change. Examples of these uses include analysis of 1) the Superb Fairy-wren and Noisy Miner, whose local distributions are negatively correlated; 2) the Superb Fairy-wren and Australian King Parrot, which show opposite patterns of distribution north and south of Sydney Harbour; and 3) the Channel-billed Cuckoo which appears to have been much more common in Sydney in 2007 than in 2006. The Birds in Backyards Guidelines for Urban Bird Habitat and the backyard bird surveys are increasingly being used by local councils in Sydney as tools to assist initiatives to maintain urban biodiversity.