Abstract
When females mate promiscuously, rival males compete to fertilise the ova. In theory, a male can increase his success at siring offspring by inducing the female to lay more eggs, as well as by producing more competitive sperm. Here we report that the evolutionary consequences of fecundity stimulation extend beyond rival males, by experimentally uncovering effects on offspring. With experiments on the burying beetle Nicrophorus vespilloides, we show that smaller subordinate males are better able to stimulate female fecundity than larger, dominant males. Furthermore dominant males also benefit from the greater fecundity induced by smaller males, and so gain from the female's earlier promiscuity ‐ just as predicted by theory. By inducing females to produce more offspring on a limited resource, smaller males cause each larva to be smaller, even those they do not sire themselves. Fecundity stimulation thus promotes the non‐genetic inheritance of offspring body size, and provides a mechanism for telegony.
Highlights
We exploited the remarkable natural history of burying beetles Nicrophorus vespilloides to analyse the importance of fecundity stimulation in sperm competition and its effects on offspring
Females were allowed to mate for an equal time period with two different males in succession, generating four treatments in all: a Large male followed by a Small male (LS) and a Small male followed by a Large male (SL), a Large male followed by another Large male (LL) and a Small male followed by another Small male (SS)
We found that Small males were more effective at stimulating female fecundity than were Large males (Fig. 2): they increased the number of eggs laid by females (Fig. 2A), and thence the number of larvae that dispersed away from the carcass to pupate (Fig. 2B), and the number of pupae that eclosed as adults (Fig. 2C)
Summary
We exploited the remarkable natural history of burying beetles Nicrophorus vespilloides to analyse the importance of fecundity stimulation in sperm competition and its effects on offspring. In this species, offspring are raised on the dead body of a mouse. We show that: (1) smaller, subordinate male burying beetles are more effective at stimulating female fecundity than larger, dominant males, and can increase their reproductive success . We further show that: (2) larger, dominant males benefit from the fecundity stimulating actions of subordinate males, because they too can sire more offspring as a result— just as recent theory predicts, though not previously demonstrated empirically. When females produce more offspring, each larva obtains a smaller fraction of the resources available on the carcass during development. Evolution Letters published by Wiley Periodicals, Inc. on behalf of Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEB)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
