Green’s Dictionary of Slang

(Aus.) to work hard, to labour; thus tigering n.

1957		Stewart & Keesing Old Bush Songs 257: Your delicate constitution / Is not equal unto mine, / To stand the constant tigering / On the banks of the Condamine.
1973		R. Robinson Dry of Things 385: He was a well-built young man, and a good worker as I was to find out; but then I had done my share of tigering and I reckoned I could hold my own.