(1) The distributions of three partially sympatric kangaroo species, Macropus giganteus (Shaw), M. fuliginosus (Desmarest) and M. rufus (Desmarest), were analysed to determine their climatic characteristics. (2) M. giganteus occupies areas only where rainfall either has little seasonal trend or where rainfall in summer exceeds winter rainfall. (3) M. fuliginosus is found in areas of uniform or winter rainfall. (4) Seasonality of rainfall has little influence on the distribution of M. rufus. Instead, its distribution reflects interaction between mean annual precipitation and mean annual temperature. (5) The extent of sympatry and allopatry appears to be determined by the independent reaction of each species to specific and differing climatic stimuli rather than by biological interaction between species
