Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, Université François Rabelais de Tours, 37200 Tours, France
| Pairwise contests for indivisible resources are common in the animal kingdom. Classically, who wins and who loses depends on differences between contestants in their abilities to acquire and retain the resource (Resource Holding Potential, RHP), and in the value that they place on the resource (Resource Value, RV). Prior conflicts can also strongly influence performance during later contests: a victory usually increases, while a defeat decreases, the probability of winning a subsequent conflict. I study contest behaviors in parasitoid wasps fighting for hosts on which to lay their eggs, and I will demonstrate the relative effect of asymmetries in RHP, RV and prior contest experience in different species. In particular, my recent work in Eupelmus vuilleti revealed for the first time the existence of a winner effect in the absence of a loser effect. This observation, so far unpredicted by game-theoretical models, should be considered in developing further theory on this topic. |