Question Statement:
The natives of Australia were always few in number. Australia produced no grain of any sort naturally; neither wheat, oats, barley nor maize. It produced practically no edible fruit, excepting a few berries, and one or two nuts, the outer rind of which was eatable. There were no useful roots such as the potato, the turnip, or the yam, or the taro. The native animals were few and just barely eatable, the kangaroo, and the koala being the principal ones. In birds alone was the country well supplied, and they were more beautiful of plumage than useful as food. Even the fisheries were infrequent, for the coast line is unbroken by any great bays, and there is thus less sea frontage to Australia than to any other of the continents, and the rivers are few in number.
What is the main idea of this passage?