Rattlesnakes aren't to be trifled with, but if you're trying to collect the sound of every creature in the West that slithers, hops, flies or flops, distance isn't a luxury you can afford.
"You get yourself in some strange situations," said Jeff Rice, a soft-spoken University of Utah research librarian who's trying to create the first comprehensive — and free to the public — archive of natural sounds in the West.
Minutes later he was squatting in the hills above Salt Lake City, training his lightweight parabolic microphone toward a Great Basin rattlesnake a few feet away.
The snake, caught by wildlife agents that day in a backyard, offered a few doubtful quiet moments. Finally, though, it let loose a long dry rattle, both eerie and fascinating, that unmistakably said "keep away."
"I knew he'd come through," Rice said, grinning like he'd been given a Christmas present.
A clearinghouse for sound
The recording, reduced to a short clip, will be added to the Western Soundscape Archive, a Web-based sound clearinghouse headquartered at the university library.
Although it's just a year old, the site already has more than 800 recordings of birds, mammals, reptiles and amphibians from 11 Western states. It will also feature "ambient soundscapes" from wild places across the region.
The sounds will be available to teachers, scientists and anyone else interested in hearing the odd murmurings of a sage grouse, javelina, Columbia spotted frog or mountain-dwelling moose.
The landscape recordings could also provide an important audio snapshot that could be used for comparison later when trying to understand how animals respond to encroaching subdivisions, oil and gas development, a warming climate, or other changes.
Repeat photography can reveal changes in a limited area, but repeated recordings offer broader insights, said Kurt Fristrup, a scientist with the National Park Service's natural sounds office in Fort Collins, Colo.
Many of the sound clips on the archive have been donated. Some, Rice had to get himself.
He has hunkered down in Utah's remote San Rafael Swell to record the chatter of beavers; logged hours on the Nevada side of Lake Mead listening to relict leopard frogs; and visited a laboratory to tape the Northern grasshopper mouse, a pint-size rodent that perches on its hind legs to offer a shrill whistle of warning.
"It's like a squeaky door," Rice said.
Prepared, with a sense of adventure
In the field, animals tend to be most active in early morning and evening. Rice comes prepared with hand-held digital recording equipment and a sense of adventure.
"You leave at 2 a.m. and find yourself wandering around bleary-eyed in a swamp," he said. "Sometimes you wonder what you're doing."
The work has its own quirky challenges — he's learned not to wear clothes that ripple noisily in the wind — and an urgent, serious side too.
As natural places disappear, so do the animal sounds that decorate them.
The World Conservation Union estimates that one in three amphibian species is at risk for extinction. Rice, 41, wants to capture as many on tape as possible before they're gone.
"It's very much a race against time," he said.
He figures the library has recordings of about 75 percent of the 53 frog and toad species in the West. It has about 70 percent of the birds and dozens of mammal and reptile recordings.
The recordings, even heard from the safety of a desktop, can stir something primal in the DNA, a sudden flight response, for instance, in the case of the rattlesnake.
"Responses to those kinds of sounds are almost reflexive," Fristrup said.
An educational component
He said Rice's archive could help people learn what animals they're hearing in the wild, even if they can't see them.
"Most of us learn to ignore what our ears tell us and focus on the task at hand because we live in really noisy habitat," Fristrup said. "But in some ways, hearing is the most alerting sense, directing us to things that matter."
There are already several natural sound archives available on the Web, including the Cornell Lab of Ornithology in Ithaca, N.Y., which says it has the largest sound and video archive of animal behavior.
The West, though, has never been fully represented, Rice said.
"I think we have a tendency to take for granted what we have in our own backyard," he said.