(Heard this 25 years ago, so apologies if the truth turns out to be a little different...)

Apparently the first European descriptions of Australia's large flightless bird referred to "an emu-like creature", emu being Portuguese for ostrich!!

With a minimal Portuguese population here (I can't recall ever meeting a Portuguese Australian), I guess the name went without being questioned and it's stuck. If my memory serves me correctly, the original name (well, in the Sydney dialect anyway) is "Marayong" - hence the name of the suburb near Blacktown.

stales