CAN CHANGES IN SOCIAL-BEHAVIOR HELP TO EXPLAIN HOUSE MOUSE PLAGUES INAUSTRALIA

House mouse plagues in the grain-growing areas of eastern Australia ar e a graphic illustration of the failure of social mechanisms of popula tion control that are postulated by the self-regulation hypothesis to prevent unlimited increase in numbers. Yet house mice are well known f or the strength and variety of social interactions and are clearly cap able of regulating their own numbers through social mortality. Most of the research on house mouse plagues has assumed that extrinsic agenci es - predators, diseases, food supplies, and weather - determine when and where mouse plagues will occur. Some aspects of these plagues cann ot, however, be explained that easily, among them the low phase, which may persist for 1-3 years. We focus here on the low phase of plagues and the trigger that flips a population from the low into the increase phase of a plague. Can social factors in house mouse populations expl ain the low phase, and is a change in social organization a necessary condition for generating a plague? Two possible models are presented t o suggest predictions to be tested by further studies of social mechan isms of population limitation in feral house mice.