Fig. 1

Female fecundity as a saturating function of cumulative seminal nutrients from males (r), based on the assumption that a given volume of nuptial gift will increase the female’s fitness more effectively when the female is starving. When males provide a seminal gift of size 500 (V = 500), females that mated once should seek another mating opportunity when the cost of mating is low (orange arrows, c = 100 per mating), but not under a higher cost (red arrows, c = 200). See Eqs. (1) and (2) in the main text for the details