Abstract
Cognitive abilities are pivotal to the performance of traits that are closely related to fitness. However, the selective regimes shaping the evolution of cognition, and differences in individual cognitive performance under different environmental conditions have been poorly studied. The rich environmental heterogeneity and biodiversity in the Neotropics present a compelling scenario where to study the functional and mechanistic links in the evolution of cognition. On the other hand, hummingbirds are a particularly interesting group in which to examine cognitive performance in the free-living animals. Their diet, mainly composed by nectar of flowers, varies in concentration, composition, and rate of renewal. These variables are easy to manipulate in the field, presenting excellent options for experimental setup. We explored cognitive performance in hummingbird species occurring in diverse environments. Overall, hummingbird species in the Neotropics showed similar cognitive abilities than species in the Nearctic region; however, our conclusions are limited by the few studies that have been carried out. Among different habitats, environmental heterogeneity seems to drive the development of cognitive abilities, however mediated by individual traits such as sex and social status. This could explain why, across all the studies, we observed important individual differences in cognitive performance. In our opinion, the role of these variables should be further assessed by integrating physiological traits, such as endocrine levels and energy balance. Thus, integrative and comparative studies in hummingbirds in the Neotropics could shed light on the different selective pressures that might have shaped the evolutionary trajectory of avian cognition.
Marcelo Araya-Salas
Research Associate
My research interests include evolutionary behavioral ecology, cultural evolution, scientific programming and all possible combinations of them.