Vocal Diversity as a Driver for Biodiversity – BiSEV

Vocal communication is one of the most spectacular modes of interaction, especially in birds. Being involved in both attraction and distancing, birdsong plays an important role in sexual selection and is linked to the reproductive and adaptive success of birds, playing a crucial role in their evolution. How has vocal diversity evolved and what mechanisms promote it? What role does vocal diversity play in the speciation process of birds, and more generally, in generating biodiversity? These are the questions I want to answer in this project. I aim to 1) explore the origin and evolution of vocal diversity in birds to determine the structure/function relationship of sound production, 2) explore the biomechanics that enables vocalization and the associated performance limitations in living birds, and 3) link anatomical and functional diversity to the diversity of sounds produced. To do so, I will study bird species with different vocalization strategies, integrating classic dissections with cutting-edge methods of in situ microanatomy visualization of the entire vocal system. I will visualize and describe these structures in motion, thanks to the combination of Xray video methods (XROMM), fluid dynamics studies (3D PIV), and acoustic recordings, to unravel the previously unobservable, hidden structures of the avian vocal tract during birdsong in a broad diversity of bird species. By comparing the biomechanics of birdsong in different scales (individuals, sexes, and species), using phylogenetic comparative methods and modelling, I will reveal structures of functional interest to understand morphological response to functional, physiological, physical, and evolutionary constraints. This work, participating in the global exploration of biodiversity will open new avenues for studies in other animal systems (e.g., mammals, amphibians) to better understand how vocalization fosters diversity and to quantify its impact on the generation of biodiversity.