Why is the kookaburra Australian?

Perhaps the kookaburra is the NSW bird emblem because it is common to that state. The kookaburra occurs naturally throughout the eastern Australian mainland states and areas of the north.

Alternative explanation:

The kookaburra may also have been chosen as the state bird emblem as kookaburra is a loan Word from the Wiradjuri guuguubarra. The Wiradjuri people are indigenous to New South Wales.