Fear factor figures in snake study

MOSES COULEE, Eastern Washington — Sagebrush crunches under boots as rattlesnake researchers wade through the dense growth, holding an antenna, listening to a soft bleep, bleep, bleep from their equipment.

The bleeping gets stronger the closer they get to the transmitter, which is glued to the tail of a 2-foot-long rattlesnake.

"He's been moving around a lot; I have no idea why," said Lisa Hallock, herpetologist with the state Department of Natural Resources. She has found her snake snugly coiled under a bush, a few hundred yards from where the creature was caught. "Without this telemetry, we'd never be able to find an individual snake again."

Hallock knows many people might think this is an odd project. Why would anyone want to spend the better part of October catching rattlesnakes, gluing tiny transmitters to their scaly bodies, then tracking them through the coulee's stony, shrub-filled ravines?

Researchers see this first-ever study in Eastern Washington as an opportunity to discover how and where rattlesnakes hibernate in this region. Although many people loathe these venomous creatures, little is known about their behavior.

Researchers like Hallock, the project's lead scientist, wonder if they hibernate in groups or separately, if they tend to go back to the same winter dens years after year, or if they hibernate with other snake species.

Researchers are also unclear on how many rattlesnakes there are and whether the population is growing or shrinking.

"Rattlesnakes are something most people don't think about or try to ignore. They're something so many people are afraid of," said Chuck Warner , a Nature Conservancy project manager who has been assisting in the rattlesnake project. "But they're part of understanding what holds this whole system together."

The research is not purely academic. The practical result is that if researchers know how rattlesnakes migrate, they can help identify where roads, trails or other uses should be avoided.

Said Hallock, "It's important to know where they overwinter, so we know where they are, and we don't build roads or trails in those places, because people and snakes don't get along."

The project is being funded by the federal Bureau of Land Management and the state Department of Natural Resources, with the Nature Conservancy pitching in staff support. The bureau paid for the 17 transmitters, which are $130 apiece.

Hallock hopes to use all of the transmitters, but so far the team has found only a dozen snakes. The project will continue for several more weeks, until the transmitter batteries die and the bleeping stops.

The transmitters don't hurt the snakes, and the fingertip-sized gadgets will be lost when the snakes shed their skin.

To protect themselves from the cold, they slither deep into loose rock of the talus, just below the coulee's sheer column walls. They tend to hibernate on south-facing slopes; the colder it gets, the deeper into the gravel they slither.

They may go months without eating, so to conserve energy they enter a comalike sleep where their body functions slow down. In the spring, the snakes emerge and head to the lower shrub-steppe coulee floor.

The coulee itself — a massive basin carved eons ago by rushing flood waters — has a rugged, harsh beauty. Its steep rock walls are slowly eroding, shedding their face to form the gravely talus that slopes up to the walls. The coulee floor is lined with sweet-smelling sage, sun-bleached grasses and shrubs.

"It's a subtle beauty," Hallock said. "You can't see it from the road, but in the spring, when all of the tiny flowers bloom, it's amazing."

Rattlesnakes tend to be elusive creatures, which makes them difficult to study, Hallock said. They tend to be most noticeable in the autumn and spring months, when they migrate to and from their winter-den sites.

Rattlesnake bites can, in rare cases, be deadly. Despite what researchers say is the Western rattlesnakes' fairly mild disposition, many are killed by people who have an innate fear of them.

"The more aggressive ones have been eliminated," said Neal Hedges, area wildlife biologist with the Bureau of Land Management. "These animals have been persecuted over the years. It's not to a rattlesnake's advantage to let people know where they are."

The snakes are being tracked on land owned by the Bureau and the Conservancy. Both agencies own thousands of acres throughout Moses Coulee near Ephrata, about 50 miles outside Wenatchee.

To find out where the snakes den, researchers must catch them on their way there. To do that, the team has been spending mornings treading through the brush of the coulee's basin, using long sticks and rods to prod under bushes and vegetation, listening for a telltale warning, the sch-sch-sch-sch that comes from a snake's rattle.

"No matter how often I hear it, it startles me every time," Hallock said. "It works very well as an alarm, as I assume it does with all animals."

Once caught, the snake is prodded into a long, clear plastic tube. It slithers in headfirst, so most of its body is inside, while its tail dangles outside. This way, the researchers don't have to worry about the snake striking at them while they glue on the transmitter.

Then they release the snake near where it was found. Every day, Hallock tracks the snakes' movements, looking to see where and when they settle in for the winter. Hallock plans to be back in the spring, to build on her research.

She plans to install drift-fence traps near the hibernation sites of snakes she tracked this month. A drift-fence trap is a low, long fence. The animals will follow the fence, looking for a way around it, and end up in a wire-mesh trap. Hallock will count the snakes each day and set them free. That project may help give researchers some baseline rattlesnake numbers for the coulee area.

"We run into sportsmen and ranchers who say they used to run into more of them," Hedges said. "They say the numbers seem to be diminishing, but we really don't know."

It's rare to have a chance to study these creatures, which tend to be about 2 feet long and have brownish blotches along the back and black and white crossbars on the tail. There just hasn't been money available for this kind of research, Hallock said.

Snake studies have not been well-supported since they aren't the cute, cuddly creatures people coo over, Hallock said. "Snakes are what people think of as evil-looking, with the vertical pupil and the scales over their eyes," she said. "Snakes are so hated, a lot of people will kill them if they get a chance."

Rachel Tuinstra: 425-464-2580 or rtuinstra@seattletimes.com