Fig. 4.

Individual phase planes of 1,000-year survivals (Fig. 2A) for each of 11 pure broods of 10- to 20-year cycles (numbers shown) with the Allee effect. The extinction thresholds are set as Nc = 100. The two parameters are juvenile survival rates S (y axis: range = 0.91–0.97) and adult emergence rate E (x axis: range: 0.13–0.35). The survival areas are larger in 13- and 17-year cycles, followed by 11- and 19-year cycles. Those of non-prime-numbered cycles are all smaller.