Meeting Abstract
Investment into aggressive behavior may depend on motivation to fight, and motivation can be highly influenced by the value an individual places on a contested resource. Female Betta splendens (hereafter bettas) are known to be aggressive towards other females, particularly when first establishing a hierarchy that allows predictable access to resources. We tested whether variation in resource value affects the level of aggression between female bettas. A dyad of female bettas were sequentially presented with low and high value resources of two types: either non mate-based resources (small food stimulus, large food stimulus), or mate-based resources (small male stimulus, large male stimulus). We monitored aggressive interactions between the dyad of females as they competed for access to these resources and compared aggressive behavior when faced with either a high-value or low-value resource. We found that aggressive behavior, particularly aggressive signaling interactions, were higher among females when competing for more food compared to less food. There was no significant difference in aggression when we varied male size. These results suggest that females modulate their investment in aggression based on a perceived quantity of food-resources weighed against potential negative costs of a fight. There was no detectable difference in female aggression based on stimulus male body size, indicating that females may not use male body size as an indication of resource value. While male aggression and dominance are well studied, we recommend that females should also be the subject of study, especially because females’ aggressive phenotypes are likely to better reflect the effects of social selection for access to non-mate based resources.
