The Red kangaroo, Megaleia rufa (Desmarest), in north-western New South Wales. 1. Movements

Abstract

Fluctuations in relative density of populations of red kangaroos were measured in an area of north-western New South Wales using aerial and ground census methods. Density estimates by both methods revealed large fluctuations in numbers during the study-fluctuations in which movements of animals to and from the area probably played a part. That kangaroos do move the relatively long distances necessary to explain the fluctuations was shown by movement of marked animals. The longest recorded movements were 135 miles from the point of release. There did not appear to be any main direction of movement, nor was there clear evidence of differential age- or sex-class mobility. On the other hand, a proportion of the population remained sedentary. The pattern of density changes between fixed quadrats over a period of time was consistent with the idea that within the kangaroo population there was a spectrum of mobility types, which resulted in some of the population accumulating in relatively more favourable parts. Indices of density of red kangaroo populations were obtained from extensive aerial censuses and more intensive ground counts on six habitats which differed mainly in the species composition of their pasture. No differences in density of kangaroos were detected between habitats except that a flood plain, although occupying only a small area, was extremely attractive to kangaroos at certain times because it was much greener than the other habitats. The greatest densities of kangaroos were associated with green pasture when it was available, but in dry times the greatest density was associated with long dry grass.