Undergraduate scholars advance acoustic research in national parks

A scuba diver installs an underwater microphone for acoustical monitoring in National Park of American Samoa
NPS staff deployed an underwater microphone, or hydrophone, at the National Park of American Samoa, which recorded the underwater acoustical environment 33m below the surface for one entire year, beginning in June 2015.


The National Park Service has a long history of partnering with universities to advance scholarship and science-based stewardship. Engaging faculty, students, and conservation professionals across disciplines, the alliances provide opportunities for research and fieldwork that mutually enrich the exchange.

In one such partnership between the NPS Natural Sounds & Night Skies Division and the Colorado State University Sound and Light Ecology Team, undergraduate students work in the CSU Listening Lab to discover and assess a spectrum of acoustical data collected in national parks around the country. The primary goal of the lab is to aid in the understanding of natural soundscapes by providing a resource to efficiently analyze the thousands of hours of natural and anthropogenic, or human-caused sounds, recorded each year. Park managers use this information to make informed management decisions about their park’s soundscapes, or acoustic environments. Students working in the lab have additional opportunities to use the data for designing unique studies that answer their own questions about park soundscapes. In many cases their work is presented at undergraduate focused research conferences. This spring semester three CSU students—all seniors from the Department of Fish, Wildlife, and Conservation Biology—presented their projects and were recognized for their efforts:
Spectrogram shows presence of biological sounds and human-associated noise in underwater subsamples gathered in the National Park of American Samoa.
Abby analyzed a representative subsample of acoustic data collected from the underwater recordings at the National Park of American Samoa. The spectrogram shows patterns of biological and anthropogenic activity.

Abigail Crowder

Discovering patterns of biological and anthropogenic activity at National Park of American Samoa using underwater acoustical monitoring. Abigail Crowder analyzed underwater acoustical data collected at National Park of American Samoa, located off the coast of Australia. Her project quantified the presence and occurrence of marine species living or migrating through a region, as well as levels of human activity. In the process, she discovered temporal patterns of fish and whale sounds, and their overlap with anthropogenic noise from sources such as passing boats. Abby presented her work at the Multicultural Undergraduate Research Art and Leadership Symposium (MURALS) and Celebrate Undergraduate Research and Creativity (CURC). At MURALS she won best presentation in Science, Technology, Engineering, and Math (STEM), and at CURC she was awarded college honors. Check out her poster here.

“Most acoustic research has focused on terrestrial habitat, not marine settings,” said Crowder. “It was fascinating for me to hear the variety of underwater sounds in the American Samoa marine ecosystem. The research gives important information about what species are present or absent, how they are interacting, and how human sounds might be affecting their environment.”
Sonobat software shows acoustic waveform activity of bat calls
Sonobat software shows acoustic waveform activity of bat calls.

Tabitha Gulley

Tailoring the analysis of bat acoustic recordings to ecological research goals: effects of changing software parameters. Tabitha Gulley designed a project to assess how altering settings in SonoBat, acoustic data software used to analyze bat vocalizations, affects estimates of bat activity and species richness. She found that changing certain parameters produced different results. Her findings indicate that standardization of key settings will greatly improve scientists’ ability to precisely categorize bat presence. She presented her research at the recent meeting of the Western Bat Working Group in Fort Collins, Colorado. Check out her poster here.

“There is a lot we don’t know about bat calls because they are ultrasonic,” said Gulley. “Working with acoustic data has made me realize how important this research is for understanding bats and helping to conserve their habitat."
Portrait of acoustic biologists Trent Hawkins and Rachel Buxton
Acoustic biologists Trent Hawkins and Dr. Rachel Buxton in the Piceance Basin of Colorado.

Photo courtesy of Trent Hawkins

Effects of Anthropogenic Noise from Oil and Gas Development on Bat Activity in the Piceance Basin. As part of his honors thesis, Trent Hawkins designed a study to examine how oil and gas activity affects the distribution of bats in the Piceance Basin in northwest Colorado. In areas with noise levels above 40 decibels, he discovered that bat calls were absent. Bat activity resumed in areas where noise levels reduced. His findings indicate a correlation between oil and gas development and bat call activity.Trent presented his research at Front Range Student Ecology Symposium (FRSES), and successfully defended his honors thesis. Check out his poster here.

“As anthropogenic noise increases, the ability to quantify damage to wildlife ecosystems is becoming increasingly essential. Bat species are especially vulnerable, and acoustic ecology is a non-invasive way to monitor their populations,” said Hawkins. “Working in the Listening Lab has given me invaluable field and lab skills that I will use throughout my career to advance bat conservation.”

Discover all the interesting research and outreach coming out of this lab, including a new study written by researchers at Colorado State University and the National Park Service and published in the journal Science, which shows that even though parks and protected areas continue to be quieter than surrounding lands, noise now intrudes into remote areas, including some national parks.

Learn more about what the National Park Service is doing to protect natural sounds.

Posted by Julie West, commumications specialist, Natural Sounds and Night Skies Division

National Park of American Samoa

Last updated: May 9, 2017