The Distribution of Red Kangaroos in Relation to Range Regeneration.

Abstract

Pastoralists frequently claim that attempts at range regeneration in arid and semi-arid areas are thwarted by kangaroos. This paper examines the possibility that the impact of kangaroo grazing is exacerbated by an influx of kangaroos onto regeneration sites. The amount of kangaroo dung in a 7500 ha paddock in arid Western Australia increased six-fold over a 15-month period following the removal of sheep. A similar influx was apparent in another destocked paddock that provided unusually high offtake of kangaroos by a commercial shooter. The amount of kangaroo dung remained relatively stable in a control paddock that was stocked. Some areas subject to cultivation and reseeding with native shrubs also showed increased amounts of kangaroo dung, indicating relatively intense kangaroo grazing. Radio-tracking of 46 kangaroos showed them to be mostly sedentary, suggesting that 'invading' kangaroos emerge from the local area. This conclusion is contrary to the widespread view that kangaroos migrate from distant locations. Thus, kangaroo control programs on sensitive areas are likely to be long-lasting because incursions are predominantly from local populations.