Meeting Abstract
Avian hatchlings on the precocial-altricial spectrum are characterized by their external appearance, rate of overall body development, and by their sophistication of feeding behaviors. Among these, potential for cranial kinesis (e.g., coordinated motion of intracranial joints) is presumed to vary predictably, with precocial birds consistently demonstrating mature cranial musculoskeletal anatomy as compared to their altricial counterparts, regardless of absolute body size. To formally evaluate whether early feeding behaviors are reflected in hatchlings’ cranial musculature and subsequent growth, we used standard micro-computed tomography (µCT), diffusible iodine-based contrast-enhanced CT imaging, and digital dissection to study size and scaling patterns of the avian jaw to compared the delicate soft- and hard-tissue functional morphology of jaw closure and cranial kinesis in hatchling and adult birds of the precocial domesticated chickens (Gallus domesticus) and the altricial estrildid finches (Lagonosticta senegala). By documenting how early-life feeding strategies correlate to the ontogeny of avian cranial characteristics of hatchling through adulthood along this spectrum, we aim to clarify differences in developmental variation and potential flexibility in the functional anatomy of the kinetic mechanism as a framework for examining the evolutionary origins of neognathine feeding diversity that has contributed to the extraordinary success of modern avifauna.
