Acoustic signal space conservatism: a framework for signal flexibility in noise (Visiting Scholar)
Background noise interferes with acoustic communication and represents a selective force in the evolution of acoustic signals. A growing focus in the field of acoustic communication is how animals cope with noisy environments to effectively dispatch their signals. Recent advances have documented acoustic signal flexibility in noisy environments, yet others suggest that species have limited signal flexibility to reduce acoustic interference. Despite new empirical work, the field lacks a strong theoretical framework from which clear predictions can be made regarding how and why species adjust or fail to adjust signals. I will develop the acoustic signal space conservatism framework based on the idea that there are intrinsic characteristics that differ among taxa that restrict signal flexibility in response to noise interference. The type and degree of flexibility depends on phylogenetic history, current vocal function, and the nature of the interference noise. I will map vocal parameters (e.g., frequency, temporal, amplitude features) onto phylogenies to evaluate the degree to which acoustic signal space is phylogenetically conserved within and among avian taxa. I will use this framework to predict and test temporal space partitioning among co-occurring frequency space competitors and evaluate the degree to which a species' frequency space predicts sensitivity to noise pollution. This framework will provide a platform from which we can begin to reveal the phylogenetic distribution of signal flexibility across multiple acoustic signal space axes. Results will be immediately relevant to understanding the role of acoustics in structuring animal communities and for evaluating species sensitivities to noise pollution.