I felt sorry for this particular bird which we nicknamed 'Judas'. It was the sole Apostlebird around the campgrounds for the few days we camped at Blackdown Tableland National Park. As Vik's photo shows Apostlebirds are normally gregarious.
For some reason this one appears to not have a group of fellow Apostlebirds to associate with. When another camper put a mirror on the ground this bird went absolutely berserk when it saw its own reflection - sometimes appearing to be making courting movements or preening itself and at others attacking the mirror quite viciously.
So maybe it's alone because it's a raving lunatic and has been ostracised or worse (cue sinister music) maybe we're looking at the world's first bird cereal killer and it did away with the rest of the group to have to itself all the grains and bread bits dropped by campers.