emu, n. — Green’s Dictionary of Slang

emu n.

also emu-bobber

[the image of an emu pecking at the ground; note Ozwords Oct. 1996: ‘The term appears to have its origin in the early twentieth century when it was used to describe people picking up pieces of timber after clearing or burning (and bobbing up and down in emu-fashion). It was also used of people picking up litter.’]

(Aus.) a racecourse idler who searches the ground for betting tickets, accidentally dropped, which may be winning tickets.

1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 27: Emu Bobber Fossicker after discarded betting tickets.
[1993		Aus. Word Map 🌐 emu patrol. the picking up of litter from an area, usually by an organised group of people, often as a school punishment].
1996		Ozwords Oct. 🌐 emu a racegoer who picks up discarded betting tickets in the hope of finding one which has not been cashed.
2013		T. Peacock More You Bet 10: They would ‘emu’ the grounds [...] and this term ‘emu’ derives from the term ‘emu-bobbing’ which is also known as ‘stick-picking’ [...] which of course comprises picking up betting and tote tickets from the ground; and these ticket-picking types have always been known as ‘emus’.