Green’s Dictionary of Slang

(Aus.) a sparrow, esp. the (introduced) House Sparrow, Passer domesticus.

1935		Dly News (Perth) 16 Jan. 6/5: If the bird were a sparrow, in Sydney and Brisbane it would be called a sprag or spridger; in Adelaide a spoggie; in Melbourne a spriggy.
1953		S.J. Baker Aus. Speaks 104: sproggy, spudgy, or spridgy, a sparrow.
2008		Birding-Aus 13 Nov. 🌐 I have been trying to do some research on the origins of sparrows in Australia and their other names such as ‘spoggies’ ‘sproggies’ ‘spridge’ and so on.