Discovery and defense define the social foraging strategy of Neotropical arboreal ants
Flávio Camarota, Flávio Camarota , Heraldo Luis de Vasconcelos , Elmo Borges de Azevedo Koch , Scott Powell
Department of Biological Sciences, The George Washington University, Washington dc, USA; The George Washington University, USA ; Universidade Federal de Uberlândia, Brazil ; Universidade Federal da Bahia, Brazil ; The George Washington University, USA
Interspecific trade-offs in foraging strategies can facilitate species coexistence in diverse communities with overlapping resource use, especially in taxa with complex social-foraging strategies. The discovery-dominance trade-off hypothesis is often invoked to help explain coexistence of ant species that use overlapping food resources, wherein colonies of some species are better at collectively discovering new food, while others have superior social fighting abilities to subsequently assert dominance over a resource. This hypothesis has yet to be tested in diverse arboreal ant communities. We assessed the competitive outcomes of arboreal ants at new food resources, and further asked if ant body size and social recruitment size influenced the observed outcomes. We did not find support for a discovery-dominance trade-off. Instead, we identified a discovery-defense strategy, wherein the first species to collectively forage at a new food resource usually defended it successfully from other species. This suggests that the discovery phase is the most important for determining the outcome of competition over food in arboreal ants. This importance was further supported by the insight that recruitment size largely determined the access of species to food resources, not individual body size. Broadly, our results suggest that although arboreal ants rely on similar food resources, coexistence may be mediated in part by the prevalence of the discovery-defense strategy: most species have the capacity to be the first to discover newly available food resources within the complex canopy, and discovery is coupled with the ability to defend a new food resource long enough to benefit from it.