Abstract
In order to investigate the influences of seasons and the paddock size on the spatial pattern of grazing cattle, the distributions of grazing cattle on the mixed pastures were constructed on the maps of each paddock at 5 minutes intervals. The distances to the nearest neighbors were measured for each cattle and the method of Clark and Evans (1954) was used to test the difference and randomness of locations. Observations were made up with four Japanese Shorthorn steers in 1974 and four Japanese Black steers in 1975. These herds were pastured on eight paddocks of from 6.25a (25×25m) to 75a (50×150m) area during observation periods of each season. The results observed were as follws: 1) The influence of seasons In summer, grazing cattle were the most strongly aggregated of the three seasons. In autumn, cattle grazed dispersedly. In spring, grazing cattle showed the midway spatial pattern between those in summer and in autumn. 2) The influence of the paddock size In spring and autumn the larger the paddock size was, the lower the R-values, the measure of the degree to which the observed distribution departed from random expectation, were made or the more cattle grazed aggregatively. And the smaller the paddock size was, the higher the R-values were made or the more cattle grazed dispersedly. The R-values showed the one peak on the paddocks of from 35a (50×70m) to 40a (50×80m) area.
