Birth rate
The urban sprawl continues to increase at a rapid rate in most Australian cities, particularly the state capital cities, all of which (with the exception of Hobart) are metropoleis. In some centres, such as Sydney and Greater Western Sydney, Greater Melbourne and South East Queensland large metropolitan conurbations threaten to extend for hundreds of kilometres and based on current population growth rates are expected to become megacities in the 21st century. Most Australian cities population growth is a result of migration in contrast to the Birth rate and fertility rate in Australia, which is contributing to the ongoing trend of urbanisation.