Presentation Information
[C19-01]Evolutionary Transitions from Resource Defense to Lekking in Birds
*Ryuichiro Isshiki1, Hisashi Ohtsuki1 (1. Research Center for Integrative Evolutionary Science, SOKENDAI (The Graduate University for Advanced Studies) (Japan))
Keywords:
mating system,behavior,coevolution,model
Polygyny is a mating system in which a male mates with multiple females. One form of polygyny is lekking, where males assemble in a group called lek and focus only on display to attract mates. Females visit the lek, mate with a chosen male, and then return to their habitat to raise their offspring. In this system, females solely gain genetic benefits from males without direct benefits such as abundant food or safe territories, which are provided in resource-defense mating systems.
Several hypotheses have been proposed regarding the evolution of leks, particularly based on female mate choice. One key hypothesis suggests that females prefer leks because they can compare multiple males and choose those with superior genetic traits. However, alternative explanations exist, such as that females visit leks to avoid harassment by males or that males aggregate for the reduction of predation risk. The role of female choice in evolution of lekking remains unclear. This study examines whether the female preference hypothesis can explain the evolution of leks, by using a mathematical model that isolates relevant factors. In particular, our model explicitly considers underlying genetic structure and incorporates the fact that resource-defense mating system is an ancestral one.
We assume that both males and females evolve preferences for either lekking or resource-defense territories. Evolutionary simulations revealed four different evolutionary outcomes: (1) lekking evolves, (2) only resource-defense mating evolves, (3) the two strategies alternate, and (4) both coexist. We find that female preference promotes the evolution of lekking. We also found that if female preference is too strong, coexistence between lekking and resource-defense mating systems occur. In this presentation, we will discuss the evolutionary stability of those four patterns and their implications for lek evolution dynamics.
Several hypotheses have been proposed regarding the evolution of leks, particularly based on female mate choice. One key hypothesis suggests that females prefer leks because they can compare multiple males and choose those with superior genetic traits. However, alternative explanations exist, such as that females visit leks to avoid harassment by males or that males aggregate for the reduction of predation risk. The role of female choice in evolution of lekking remains unclear. This study examines whether the female preference hypothesis can explain the evolution of leks, by using a mathematical model that isolates relevant factors. In particular, our model explicitly considers underlying genetic structure and incorporates the fact that resource-defense mating system is an ancestral one.
We assume that both males and females evolve preferences for either lekking or resource-defense territories. Evolutionary simulations revealed four different evolutionary outcomes: (1) lekking evolves, (2) only resource-defense mating evolves, (3) the two strategies alternate, and (4) both coexist. We find that female preference promotes the evolution of lekking. We also found that if female preference is too strong, coexistence between lekking and resource-defense mating systems occur. In this presentation, we will discuss the evolutionary stability of those four patterns and their implications for lek evolution dynamics.