Cooperative Bargaining During Mate Competition: A Test in Male Guppies

Maddisen Bell


Competition between individuals of the same sex for mating opportunities is a well-observed phenomenon, yet the role or presence of cooperation remains rarely explored. Previous research has primarily found that cooperative or altruistic behaviors occur in social animals who live in close quarters and are related or have some form of reciprocation for the cooperative behaviors. However, cooperation between two randomly picked individuals when mating opportunities are limited has not been studied. This study used Trinidad guppies (Poecilia reticulata) as a model species to investigate whether cooperation occurs between two males in limited and equal female availability scenarios and whether it could fall within an equal trade-off between the two males. Four experimental trials involving various males and females were conducted to examine courtship length and behaviors between males and females. Aggressive behaviors between males were analyzed as well. The findings were that courtship length was impacted by the addition of males when females were limited. This suggests that courtship is hindered in situations with limited female presence and excess males, leading to increased male competition. Some bargaining behaviors occurred between the males, but these behaviors were limited. These results contribute to our understanding of the complex dynamic of mating behaviors and indicate a need for further research to identify underlying cooperation in a reproductive context.