Long-billed Corella
Cacatua tenuirostris

The Long-billed Corella is a cockatoo native to Victoria and SA where it is now becoming uncommon in the wild. Feral populations from aviary escapes exists in a few Australian cities, including Sydney. The first two photos are of wild birds in Monash, Victoria and the last two are feral birds in Sydney. They are closely related to the Little Corella, which is also present as a feral bird in Sydney, but are larger (38-41 cm for Long-billed against 36-39 cm for Little), have more red around the eyes and throat and a longer bill. As with other corellas, they use their bills to dig for roots, bulbs and seeds.
 

1-2: Monash, Victoria, 17/12/2010.
3-4: Centennial Park, Sydney, 28/02/2010.