One grad student knows the sound of silence in the Everglades
- Laurie D. Babcock
- October 1, 2024
- News
- Contributors: Chris Noonan, Video | Laurie Babcock, Photos
7 – minute read
Charley Vance smiles sheepishly when he’s asked, “If a tree falls in the forest and no one is around to hear it, does it make a sound?” The answer will be part of his master’s thesis on bioacoustics.
“I remember when I was younger, being able to see the Milky Way just by looking out the window. Now, light pollution makes that difficult,” says the Florida Gulf Coast University environmental science grad student. He says it’s the same with sound. “There aren’t many places left in the world where you can just go and enjoy the natural sound environment. It’s a rapidly disappearing resource.”
On an August day, Vance stands in an area of the Picayune Strand State Forest in eastern Collier County ravaged by a May 24 wildfire.
“It’s harsh conditions out here. This area has been inundated with at least a foot of water for the last month, and it’s been very difficult to traverse in the ATVs,” he says, standing in ankle-deep water lush with vegetation. Two months earlier, this land was barren and burned.
Immediately after the wildfire, Vance installed a weatherproof wildlife audio recorder in hopes of capturing the sounds of the Everglades regrowing. He has similar recording devices in six other locations throughout the state forest.
The equipment captures the sounds of wind rustling through trees and things splashing in the water, as well as airplanes, Forest Service vehicles and hunter’s gunshots from farther away. “But we’re really looking for certain groups of animals, like birds, frogs and insects,” he says.
Since mid-May, he’s been collecting one minute of sound data every five minutes. Every 24 hours, he captures 288 minutes of data from each recorder; that’s more than 1,800 hours of sound across seven sites.
The area hosting Vance’s audio equipment was once a planned real estate development of roughly 88,000 acres in Collier County. When the developers went bankrupt, the site sported four major canals and a network of paved roads. In 1984, the state began buying parcels of land south of Golden Gate Estates to turn the area into the Picayune Strand State Forest. Since construction began in 2004, it’s been a cornerstone of the Comprehensive Everglades Restoration Plan (CERP). The Picayune Strand Restoration Project aims to restore 55,000 acres of habitat in the Everglades by 2026. Home to diverse wildlife, this area is being transformed from a grid of asphalt roads and deep canals back into a thriving ecosystem.
“Think about what animals need to survive — water, food, shelter. But they also need the ability to communicate,” Vance says. His master’s thesis aims to characterize the area’s soundscape, to make a complete log of the animals and insects and their sounds to get a measure of the ecosystem’s health.
“The value of this bioacoustics project comes from studying short-term indicators of resilience, or how tough this system is, at a scale that hasn’t been done before,” he says. Traditionally, when examining ecological resilience, researchers have to be on-site to capture or measure the environment. When they can’t be in an area 24/7, Vance says “they tend to underrepresent how species are affected and overrepresent how they recover.” His study will establish a metric to rapidly assess how resilient the ecosystem is by analyzing three groups of organisms: birds, frogs and insects.
“You can learn so much just by listening,” Vance says.
The sound of silence
“Part of feeling connected to this landscape is knowing the sounds,” says Win Everham, professor of ecology and environmental studies in The Water School and Vance’s faculty adviser. He knows that when people encounter unfamiliar sounds in nature at night, they might feel anxious or scared if they can’t easily recognize the source of those sounds.
Standing ankle-deep in water a few feet from Vance, Everham pauses to listen. He identifies a red-shouldered hawk by its call, a high-pitched “keer” repeated several times.
“Charley’s bioacoustics work is really part of a larger, ongoing process,” he says. “We know that ecosystems are adapted to specific, naturally occurring conditions — like floods, droughts and fires. What we don’t fully understand is whether these natural disturbances are beneficial during the recovery process as we restore the landscape. Charley’s project is about understanding whether these disturbances help move the restoration forward or if it occurs at the wrong time and hinders the recovery.”
He stops short at another bird call; this one a shrill, rolling “kwirr.” A few feet away, Vance turns, too, and the two men stand quietly listening to a red-bellied woodpecker.
“What we think of as silence is often just the absence of noise, but I think of silence as more of a natural sound level,” Vance says. “Animals use sound for everything, and it’s essential to maintain a natural level so they can thrive.”
Listen to one of Charley Vance’s recordings of the Picayune Strand State Forest at dawn.
Capturing the call of the wild
Vance hopes his work will inspire other FGCU students to study the Everglades. With so much left to explore, from the subtle shifts in wildlife behavior to the long-term impacts of environmental restoration, there are countless opportunities to contribute to the research.
“We’ve been able to document the full transition of the sound-producing wildlife out here from dry season to wet,” says Vance. His research will provide a valuable dataset and insights into the resilience of wildlife communities and help assess the success of restoration efforts like those in the Picayune Strand State Forest.
While Vance’s audio recordings may lead to a definitive answer to that age-old question — “if a tree falls in the forest and no one is around to hear it, does it make a sound?” — until he can analyze the data, he’s staying silent on the issue.