The evolution of strategic male mating effort in an information transfer framework

Abstract

Sperm competition theory predicts that males should use cues indicating the risk and intensity of sperm competition to tailor their sperm investment accordingly. Rival males are an important source of social information regarding sperm competition risk. However, revealing such information may not be in the rival males' interest. Here, we use a theoretical approach based on informed and uninformed games to investigate when information transfer about sperm competition risk to competitors is beneficial for a male, and when it is not. The results show that signalling to potential future mates that a female has already mated is beneficial when the signalling male has a sperm competition disadvantage, whereas it is unfavourable when the signaller has an advantage. The reason for this counterintuitive result is that the rival males' optimal response is to reduce sperm investment when the signaller has a disadvantage and, conversely, to increase investment when the signaller has an advantage. Furthermore, we analysed scenarios where males use alternative reproductive tactics. In this situation, signalling the awareness of sperm competition risk rarely pays; instead, it is beneficial to maintain an information advantage. Thus, it may be beneficial for bourgeois males to accept cuckoldry instead of revealing their sperm competition awareness to reproductive parasites. These results provide new insight into the evolution of communication between rivals in the context of sperm competition.

Effects of social information on life history and mating tactics of males in the orb‐web spider Argiope bruennichi

“…Plastic traits, as for example life history strategies or alternative mating tactics, are known to respond to cues that provide social information (Engqvist & Taborsky, ; Kasumovic & Brooks, ; Kodric‐Brown, ; Rodriguez, Rebar, & Fowler‐Finn, ). Upon maturation, females of Argiope bruennichi emit a volatile sex pheromone that attracts males (Chinta et al., ).…”

How pre- and postcopulatory sexual selection influence male mating decisions in a promiscuous species

“…Supporting this last hypothesis, a theoretical study suggests that males should only transfer such information to rival males when they are in disadvantage on sperm competition (Engqvist & Taborsky, 2017). In fact, the First scenario is the one where the risks are higher, as males have more to lose than those who approached Second or those that were alone with a female the entire time.…”

Conceptual developments in sperm competition: a very brief synopsis

“…Since then, many 'sperm competition game' variants on this basic model predict sperm allocation under different assumptions about a male's information at the time of ejaculation [25]. An interesting recent approach investigates when information transmission between males about sperm competition level is likely to evolve [42]. Most models assume that sperm competition follows the 'raffle principle' [43]-sperm are analogous to tickets in a fertilization lottery.…”