Meeting Abstract
Understanding why some groups of organisms have more diverse traits than others remains a key challenge in biology. This challenge stems, in part, from the dynamic interplay between species traits and how individuals use these traits in their daily lives. For example, innovations in foraging behavior can drive morphological diversity by opening up new ways of interacting with the environment, or limit diversity through functional constraints associated with different foraging behaviors. Several classic examples of adaptive radiations in birds show increased variation in ecologically relevant traits. However, these cases focus on geographically narrow adaptive radiations; consider only morphological evolution without a biomechanical approach; or do not investigate tradeoffs with other non-focal traits that might be affected by use of different foraging habitats. Here, we use X-ray computed tomography, biomechanical modeling, and multivariate comparative methods to explore the interplay between foraging behavior and cranial morphology across kingfishers, a global radiation of birds with variable beaks and foraging behaviors, including the archetypal plunge-dive into water. Our results reveal several independent gains of plunge-diving behavior in the group, as well as distinct patterns of morphospace occupation for different foraging behaviors and considerable rate variation among skull regions. Our results have implications for biomimetic design of novel drag-reducing structures and shed light on how macroevolutionary trends relate to changes in the adaptive landscape over evolutionary timescales.
