Acoustic Niche Patterning on the Harbor Islands and Beyond
Delivered at the 2011 Boston Harbor Islands Science Symposium
The acoustic niche hypothesis, an extension of ecological niche theory, posits that the sound spectrum is a limited resource over which sound-producing species compete. Therefore, species should evolve to partition the sound spectrum in a way that minimizes acoustic competition. Prior research has corroborated the hypothesis; however, most of this research examined small groups of closely related species. Our goals were (1) to test the hypothesis that all of the calling species within a community partition the frequency spectrum, and (2) to investigate possible trends in frequency partitioning across time and across taxa. We compared frequency partitioning within acoustic communities in Massachusetts. The degree of frequency partitioning increased over the course of a day from morning to night and increased over the course of the summer, with partitioning most pronounced in late summer. We propose that the main cause of both these trends is the maturation of Orthopteran species in late summer. Partitioning of the frequency spectrum may be a method to reduce competition between acoustic species, particularly for singing insects, and the frequency of a species' call may constrain with which other species it can coexist.