Sydney Harbour and surrounding areas provide a diversity of wildlife habitat and natural bushland. Birds have always been an important and easily seen part of harbour wildlife. The earliest known illustration of a local species was that of the Rainbow Lorikeet Trichoglossus haematodus. Diaries from the voyages of Cook and Banks mentioned birds, but illustrations from the area of Sydney Harbour were lacking.

We now know that over 150 species of birds occur in the region of the harbour and surrounding areas. The list for the County of Cumberland has 447 species. Many are of limited distribution and/or known from only single records. Others occur as itinerant visitors, occurring in numbers some years and absent in others. Resident species are generally numerous or readily found in specific habitats or locations. Some are migrants arriving and departing at regular intervals. Most use the area for nesting. Others simply visit after nesting elsewhere. There are species not seen since Europeans altered or completely removed their habitat.