<P> Of the 48 species of macropods (kangaroos) in Australia, only six can be commercially harvested . </P> <P> Over 99% of the commercial kangaroo harvest occurs in the arid grazing rangelands . The populations of kangaroos in these areas are estimated every year in each State by well - developed aerial survey techniques . These are sparsely timbered, (savannah) type ecosystems; hence, it is possible to fly over them and count the large animals, such as kangaroos, seen . Using either low - flying fixed - wing aircraft or helicopters, flying at heights of two to 300 meters, the National Parks authorities count the numbers of kangaroos seen over fixed transects . Thirty years of such monitoring have allowed them to develop sophisticated and accurate techniques of extrapolating out to total population numbers . Kangaroos are one of only a very few species (including humans) which have an annual census of their populations . </P> <P> Current populations stand around 25 million . This means the numbers of kangaroos in Australia are similar to cattle numbers . </P> <P> It is widely accepted that within the rangelands kangaroos are now more common than prior to European settlement . This situation has arisen due to the increased food and water supply generated by the activities of the sheep and cattle industry . Prior to European settlement, these areas had very few places of surface water from which kangaroos could drink . The pastoral industry has tapped into below - ground water supplies to the point where now very few points in the rangelands are further than 3 km from a permanent water source and no point is further than 10 km . </P>

What's the population of kangaroos in australia