(photo by Brett Donald from Wikipedia)
'Boss Cocky' is an Australian colloquialism referring to a person eminent among nonentities; someone enjoying the exercise of petty authority, usually with some element of assertiveness implied and could be used to describe the behaviour of this bird.
Nearly all the usual birds of the garden have made themselves scarce since the arrival of this fellow. No more wrens or honeyeaters and even the big Kurrawongs who normally swoop and call all through winter have been running scared.
He likes to perch as high up a tree as possible before singing his heart out. A very melodious song he proudly sings while he surveys the territory. I know he is after a few tidbits from me as he often lands quite close, a metre or so away and gives me an eyeful. Not afraid, as I seem to be in his territory. How much longer he will stick around is hard to tell but I don't mind if he makes a meal of some of those pesky Myna birds in the meantime.