• Lush vegetation on the top of Spectacle Island's North drumlin dominates the foreground. Boston's skyline can be seen in the distance.  The park's logo with tag line minutes away, worlds apart empashises the stark contrast between the city and islands.

    Boston Harbor Islands

    National Recreation Area Massachusetts

Acoustic Niche Patterning on the Harbor Islands and Beyond

Alison Ravenscraft
Ecology and Evolution
Stanford University
371 Serra Mall
Stanford, CA 94305

 

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.

Did You Know?

Graves Light

On September 1, 1905, Elliot Hadley lit the most powerful light in Massachusetts at the top of Graves Lighthouse, now in Boston Harbor Islands National Recreation Area. The first-order Fresnel lens aided in navigation and allowed for safe passage into Boston Harbor. More...