Only four giant Palouse earthworms have been found in the last 100 years — so scientists are dousing the worms with hot mustard and shocking them with electricity.
Those are the two main tricks of Palouse worm hunters, who’ve recently taken to the field in an effort to dig up information about a species so rare that the Bush administration wouldn’t declare them endangered. Not enough was known, they said.
Environmentalists hope the Obama administration will be more sympathetic. But whatever happens, they’ll need to know more about the worm. Leading the effort is University of Idaho soil scientist Jodi Johnson-Maynard, who explained their techniques to Wired.com.
wormhunt11The simplest way of finding the earthworm is “hand-sorting,” a fancy name for digging them up with a shovel. That’s how one of Johnson-Maynard’s students accidentally found a giant Palouse earthworm in 2005. Unfortunately, the shovel cut the worm in half.
Hoping to avoid a repeat, Maynard-Johnson turned to a dilute solution of off-the-shelf hot mustard. “It’s an irritant that causes them to try to come up to escape it,” she said. “It works on other worms, so probably it’ll work on the Palouse. It’s thought to be more efficient at extracting larger earthworms that burrow fairly deep, like nightcrawlers, and produce very straight, downward burrows. It flows preferentially down those holes.”
Similar in principle is electroextraction. “We have a series of probes put in the ground, and hooked up to a power source,” said Johnson-Maynard. “The worm senses the current going through the soil, and moves up to escape it.”
wormhunt2Johnson-Maynard has also tried worm grunting, in which a wooden stake is driven into the ground and rubbed with steel, producing vibrations that mimic the sound of worm-hungry moles. That works great for standard earthworms, but didn’t uncover any giant worms.
“There may not have been many worms present,” she said. “But another problem is that it could possibly work if the earthworms were close to the surface, but if they’re five to 10 feet down, that’ll be hard.”
Hot mustard and electroextraction are scheduled for use at a site in north-central Washington where several giant Palouse earthworms are believed to have been found, though formal identification was inconclusive.
“I liken this to fishing. Fishermen have a lot of patience, and that’s what this takes,” she said.
copyright: article: Brandon Keim