For years, Gary Kittleston has searched swamps for endangered red-legged frogs, waiting just after sunset. The environmental consultant now searches Watsonville Slough, a swamp east of Santa Cruz, California, with a headlamp and waders. Known by his nephews as “the frog whisperer,” Kittleston says that some years he’d be thrilled to find just one or two.
This marsh is a key habitat for red-legged frogs, who are an Endangered Species Act threatened creature due to overdevelopment of their habitats and over-hunting for their legs. A local land trust hired Kittleson to count the frogs to see if their population is growing or shrinking over the years.
This work is far from simple, however. Kittleson seeks out frogs within thick brush and listens for their low bellows amongst high-pitched cries of chorus frogs. Though the average listener would find the task nearly impossible, Kittleston has trained himself to hear red-legged frogs even while he’s speaking, searching for the telltale pattern of their call. “Chuck, chuck, chuck. It was three pulses,” he notes, determining one sound to be that of a red-legged frog.
Kittleston uses the traditional way of counting endangered animals, but this takes up significant time and manpower, providing only a small slice of data for the time periods Kittleston or consultants like him can stand in each swamp. This is why the Land Trust of Santa Cruz County recently partnered with Conservation Metrics, a data company seeking to streamline the process of measuring endangered frog counts. Kittleson helped the company put up song meters around Watsonville Slough; each little green box has a microphone to capture the frogs’ chorus all night long. Conservation Metrics employees then load each night’s recordings into a computer and create algorithms that sift through hours of audio to pick out red-legged frog calls. This process allows one person and a computer to do what would normally require an entire team of field biologists, notes CEO Matthew McKown. “Our whole point is to make conservation better, so we are trying to make it as cheap as possible,” he says.
McKown created Conservation Metrics three years ago, hoping to help environmentalists keep more accurate records of threatened populations. He says that big data is now a hot tool in conservation that can help biologists study endangered animals and threatened habitats.”What you’re going to start having is cameras, acoustic sensors, satellites trained on these important parts of the world,” he says.
Meanwhile at the Watsonville Slough, Kittleson stands waist deep in swamp water. Night has fallen and he shines his headlamp around the marsh, searching for the piercing glare of frog eyes. One frog meets his gaze. “Beautiful. Adult red-legged frog,” Kittleson says. The frog perches atop a log that floats by the water’s edge. Though Kittleson isn’t hopeful about the future of this species, he says good data is the only way to tell if conservation efforts are making progress.
Source: Harnett, Sam. “Using Algorithms To Catch The Sounds Of Endangered Frogs.” KUNC. 31 May 2016.
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