Reasons for females to feign death, inter alia: To ward off unwanted suitors & to select a persistent, strong male that fights best risks (like predators or drowning under too many males at mating)

Reproductive behaviour of the European Common Frog (Rana temporaria). Carolin Dittrich. Humbold University at Berlin, Dissertations, Jun 26 2020. DOI: 10.18452/21476

Abstract: In my thesis, I examine the mating and reproductive behaviour of the European Common Frog (Rana temporaria) in an evolutionary context. I aim to understand which mechanisms lead to the formation of pairs, if mate choice shapes the patterns of mating that we can observe and if there are benefits derived from pairing with a specific mate. The search and competition for mating partners lead to the evolution of various mating systems, strategies and tactics to increase lifetime reproductive success. The mating behaviour is influenced by natural and sexual selection, whereby both could act in different directions. For most individuals, survival is essential in order to reproduce as often as possible to increase lifetime reproductive fitness. On the other hand, reproduction could increase predation risk due to conspicuous behaviour and risks associated with mating itself. Sexual selection could favour specific secondary sexual traits, either due to advantages in intrasexual competition, or by specific preferences of the choosy sex (intersexual selection). For mate choice to evolve, there need to be benefits associated with the chosen mating partner, because choosiness involves costs in terms of energy and time constraints during mating. As an explosive breeder, the European Common Frog has to deal with time constraints during the short breeding season. The males are competing for the access to females and it is assumed that females are passive during breeding due to a high male-biased operational sex ratio. However, from an evolutionary perspective females should be the choosy sex and should decide with whom to mate, as they invest more energy into the production of eggs.