Male D. mojavensis provide an ejaculate donation to females which is incorporated into their developing oocytes. Male size is uncorrelated with donation size. Amount of this donation is depleted with successive matings, although male fertility remains constant. Males court preferentially females whose ovaries contain mature oocytes, thus ensuring the rapid utilization of their own sperm and their paternity. Females allowed unlimited access to dietary yeast exhibit high levels of fecundity, but nutritionally deprived females are not able to manufacture enough oocytes to utilize the sperm from a single mating. In the absence of dietary yeast, early female fecundity is enhanced by male ejaculate donations, but the ejaculate donation does not appear to influence total lifetime fecundity in the absence of continued remating. Females remate frequently. In natural populations, during periods of dietary stress, nutrients derived from repeated matings may constitute an important resource for total lifetime fecundity of females. -from Authors