• 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

Evaluation of the Acoustic Niche Hypothesis

Alison Ravenscraft
Alison Ravenscraft
Harvard College
e-mail author
 
Delivered at 2008 Boston Harbor Islands Science Symposium.

The acoustic niche hypothesis predicts, in a mature ecosystem, species will avoid competition by singing at unique bandwidths, or pitches, at unique times. Therefore, no two species should sing simultaneously at the same frequency. Furthermore, the hypothesis suggests more mature ecosystems will exhibit pronounced partitioning of the sound spectrum while young or disturbed ecosystems will exhibit more acoustic disorganization, with multiple species interfering on some bandwidths and no species singing at other bandwidths. If these predictions are true, then the degree of acoustic partitioning in a given soundscape should be directly related to the habitat quality and biodiversity of said ecosystem.

The ultimate goal of this project is to compare the degree of partitioning in several ecosystems from both northeastern and tropical soundscapes and to test whether this correlates to season, time of day, or ecosystem health, among other variables. Three of the northeastern ecosystems surveyed this summer were Grape, Spectacle and Thompson Islands. The project is still in the data analysis stage but the presentation will focus on what has been observed at Boston Harbor Islands thus far.

Did You Know?

Satellite Imagery of Boston Harbor Seafloor and Islands

Boston Harbor Islands is one of 14 national park that has the word "islands" in the name. Other island parks include Channel Islands in California, Apostle Islands in Wisconsin, Governors Island in New York and Assateague Island in Maryland.