Population ecology of the Japanese field vole (Microtus montebelli) in Kyushu. III. Contagious distribution in the growth phase

The distributional pattern appearing with the population change of M. montebelli was examined in restricted area of Mt. Hitome in the northern Kyushu. In native grassland, the places damaged intensely by the vole exhibited a patchy distribution bounded clearly by the uninjured area. In a grid established on the young plantation, the distribution of the points of capture was contagious and uneven during the growth phase. The points showed a tendency to spread over the greater part except the part of the shrubs growing at the northwest of the grid. In the growing population, the vole was strongly sedentary, and there appeared frequently males with a placid temper. Less agonistic behavior and reduction of the home range in the growing population results in the contagious distribution with the unusual high population density. The population with the contagion of the vole's own property, appeared to consist of one to several families.