Meeting Abstract
Competition between individuals is often decided via agonistic interactions. When individuals encounter each other, both must assess the costs of fighting against the benefits of a potential resource gained. If both individuals’ assessments determine that the cost of continued interaction is less than the benefits gained, the agonistic interaction will intensify until one individual gives up and flees. This has far-reaching ecological consequences, as losers in fights are often displaced to poorer quality food, shelter, and mate resources. Biogeographical invasion studies have shown that aggression differences between alien and native species factor into invasion success. In part, these differences mean invaders often outcompete natives for better resources. In this study, we examined the agonistic differences between a new invader to Alabama, Faxonius virilis, and a native crayfish, Faxonius erichsonianus, in dyadic interactions. Crayfish were socially isolated prior to trials. During trials, individuals were placed in a fighting arena where they acclimated for 15 minutes. Crayfish were then free to interact for 20 minutes and were video recorded from above. Interactions were scored to determine total interaction duration and the maximum behavioral intensity reached. Using this data, we can determine whether one species demonstrates significantly different levels of aggression. Preliminary trials show no significant agonistic differences across native and invasive treatments in fights between conspecifics. It is possible that success in agonistic interactions is largely irrelevant to invasion success: high fecundity and generalism may be what gives the invasive F. virilis its edge over Alabama’s native crayfishes.
