Dusky Moorhen
Gallinula tenebrosa

A close relative of the Common Moorhen, an immediate difference is the colour of the feet. Otherwise, they are very similar in form and behaviour. The first three are adults, the fourth a chick and the last a juvenile.
 

  

1: Lake Northam, Victoria Park, Sydney, 26/09/2009.
2-4: Royal Botanic Gardens, Sydney, 06/12/2009.