Variations in Distribution of Western Grey Kangaroos, Macropus-Fuliginosus-Ocydromus, in the Tutanning Nature Reserve and Their Impact on Adjacent Farmland

Abstract

The distribution of western grey kangaroos, Macropus fuliginosus ocydromus, within the Tutanning Nature Reserve, near Pingelly W.A., was monitored for six years from faecal accumulation on fixed transects throughout the reserve, and from locations of animals sighted. Animal density varied between the eastern and western halves of the reserve, but this variation could not be explained by differences in the vegetation characteristics that were measured. Significantly more use was made by the kangaroos of Eucalyptus wandoo-E. accedens open woodland than of dense areas of Casuarina huegliana or of tall kwongan vegetation. Animal numbers declined by 40% in 1982 (from 800 to 500), a drought year, and remained at this lower level for the final three years of the study. The numbers of animals seen on farmland at night were higher on crops than on pastures, and higher in areas adjacent to parts of the reserve with greater densities of kangaroos. The proportion of the population seen on farmland on any one night varied seasonally, but averaged 4.5% in 1981, before the population decline, to 5.6% in 1983, a year of very low winter rainfall. Estimation of crop damage made in one year shows that damage was restricted to those parts within 100 m of the reserve. The crop losses appear to be around 1% of paddock yields.