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Mount Spokane ice crawler may be a unique species, scientists say

Hundreds of thousands, perhaps millions of years ago, flightless, cold-loving bugs on Mount Spokane became separated from the rest of their species.

And there they lived and evolved into something a little different, unnoticed by humans until 1994.

Meet the Mount Spokane ice crawler.

A recent examination of a gene from the insect revealed that a Mount Spokane ice crawler’s DNA is about 2 percent different from the closest-known ice crawler relative.

That might not seem like much, but Sean Schoville, the University of Wisconsin-Madison assistant entomology professor who did the research, noted the difference between humans and chimpanzees in a similar test is closer to 1 percent.

“It’s quite different than the genes you find in other populations,” Schoville said. “The genetic diversity supports the hypothesis that they are a separate species.”

Ice crawlers, also called rock crawlers and scientifically called Grylloblatta, resemble earwigs to an untrained eye. They were first documented about 100 years ago.

Entomologist and wildlife consultant James Bergdahl learned about ice crawlers as a graduate student at the University of Washington. In the early 1990s, he was surveying for beetles in Eastern Washington; he discovered the ice crawlers on Mount Spokane in 1994.

“They’re so rare and infrequently collected, anywhere you find a population it’s a surprise,” said Bergdahl, who submitted Mount Spokane samples to Schoville in 2013 for DNA testing.

Ice crawlers prefer cold – temperatures around freezing – but not really cold. They live in ice caves or at higher elevations mostly in the western United States and Canada. They are thought to have lifespans of around 10 years. When the snow disappears in the late spring or summer, they go underground. But they aren’t equipped to dig, so they retreat under rocks and into crevices to escape the heat.

In the winter they often hide under the snow, but they come out at night or in calm conditions to feed on insects that were swept up by the wind from lower elevations and landed dead on the snow.

“It’s like a frozen food section,” Schoville said.

Ice crawlers have been found in many places in the West, especially in the Cascades. They’ve also been found in the Bitterroots, and as close to Mount Spokane as Polaris Peak in North Idaho’s Shoshone County.

But DNA data shows the Mount Spokane ice crawlers are more closely related to ice crawlers in the Cascades than those in North Idaho.

Hidden, but plentiful

Bergdahl took Schoville and two others to Mount Spokane to find ice crawlers in May 2014.

They first went to a forested area with no snow. They located one ice crawler nymph.

Then some of the researchers went to the developed portion of the downhill ski area. In forested areas near ski slopes they located about 10.

Schoville said that’s a reasonable haul for an ice crawler expedition. At other locations where ice crawlers had been found previously, he’s come up empty or he’s found hundreds.

When Bergdahl sent live samples to Schoville for DNA testing in 2013, he collected 40 to 60 in about eight hours of searching and sent them in a box with ice packs and leaves.

Bergdahl said the population could be large.

Even so, they mostly go unnoticed.

Jerry Johnson, who’s been a park ranger at Mount Spokane State Park for 11 years, hasn’t come across one, as far as he knows.

“Now that you say that, I’d be more hesitant to pick up a handful of snow and start chewing on it,” he said.

Brad McQuarrie, the general manager of the Mt. Spokane Ski and Snowboard Park since 2002, said he also hasn’t noticed one.

That’s not surprising, Schoville said.

Ice crawlers mostly stay out of sight in the day. They are difficult to find most of the year, and without headlamps and knowing where to look, few people would come across them.

Bergdahl has raised concerns about the ski park’s planned expansion.

In a letter to the state parks commission in 2014 when the group was considering the expansion, Bergdahl questioned why environmental studies examining the effect of the development on wildlife did little examination into ice crawlers or other invertebrates. He said Mount Spokane’s fauna is poorly documented and if ice crawlers are on the mountain, other unique creatures may be there, too.

“This is the only known population of the exceptionally unique and rare flightless insect in Washington state east of the Cascades Mountains,” Bergdahl wrote.

Bergdahl said he’s found the largest number of ice crawlers in a part of the proposed development. He questions if the ski area will be economically feasible in a few decades as a result of climate change.

“Proponents of the expansion seem to be focused primarily on short-term economic gain at the expense of the long-term ecological integrity of Mt. Spokane State Park as a whole,” Bergdahl said in an email.

Schoville said there’s some evidence that ski areas could hurt ice crawler populations. He noted a population that existed on Mount Hood ski areas no longer seems to exist.

On the other hand, some ice crawler populations have done OK near ski resorts, depending on management practices. Schoville said he found specimens near developed parts of Mt. Spokane’s slopes, though Bergdahl said that was a rare find.

In a report published in 2013 on the distribution of ice crawlers, Schoville described the Mount Spokane population as “endangered.” That’s not recognized by the state or federal government, which have not listed the Mount Spokane ice crawlers as endangered or threatened. Schoville said the label is appropriate because if the hypothesis that they are unique is correct, their habitat is extremely limited.

Mt. Spokane’s expansion project is on hold at least until August because of construction restrictions set to protect nesting and breeding times. This week, a hearing will be held to consider an appeal of the ski area’s timber permit filed by The Lands Council.

McQuarrie said the state parks commission placed numerous restrictions on the expansion to protect wildlife.

“It would be a model for environmental stewardship in a recreation environment,” he said.

More research needed

Bergdahl isn’t new to finding new species. He’s discovered two species of beetles in central Idaho now considered unique species, complete with their own scientific names.

The ice crawler species on Mount Spokane is further from that recognition.

The DNA is important evidence, but there’s more work to do, Schoville said.

Among other studies that would need to be completed before the Mount Spokane ice crawler could definitively be described as a unique species, male reproductive structures need to be analyzed to determine if they have unique and distinguishable features, Schoville said.

If those and other studies continue to support the hypothesis, a scientific report would have to be written and published.

Schoville is working on a paper describing the ice crawler’s DNA for publication this summer. For now, other analysis is “on the back burner,” he said.

Ice crawler populations have been found in many locations in the Northwest, and some of them have been found to be unique.

Two researchers at Oregon State University recently discovered that ice crawlers living on Marys Peak on the Oregon Coast are a unique species.

Ice crawlers are a bit legendary in the entomological community, and soon after Christopher Marshall started work at Oregon State he wanted to see one for himself, after learning there was a population at Marys Peak.

He and professor David Lytle found some in 2006, analyzed them and determined they didn’t fit the known descriptions of other ice crawlers. After DNA testing and other studies, they published work last year outlining their research and naming the species Grylloblatta chintimini, a name based on a Kalapuya tribal word for the peak.

Their work gives a hint of the kinds of things that must be considered before the Mount Spokane population could get its own scientific name.

Some differences that made their ice crawler unique are easier to describe. Marys Peak ice crawlers are thinner and darker in color, for instance.

But the process was long, tedious and technical. Nearly all the work required use of a microscope.

For instance, Marshal and Lytle detailed the unique male genitalia of the Marys Peak ice crawlers.

“Male genitalia of Grylloblatta are very complicated,” said Marshall, curator and collections manager of the Oregon State Arthropod Collection.

Turns out the males at Marys Peak have a “distinct secondary accessory sclerite,” according to their published research.

What makes their “accessory sclerite” unique? They look like a “square-topped tooth,” Marshall said. In other ice crawlers, this part of the male “copulatory organ” is round.

Climate change poses significant risk

Schoville’s research as a graduate student at the University of California at Berkeley focused on how insects responded to past climate change.

“Ice crawlers were one of the best insect models to represent that history,” he said.

Ice crawlers likely thrived in previous ice ages. Unable to tolerate even mild heat, they were forced to retreat as climate warmed, sometimes into isolated areas cut off from other ice crawlers.

“That’s how they diversified,” Schoville said. “They’re very poor dispersers. They probably don’t move any more than a few dozen meters in their whole lives.”

Gary Chang, associate biology professor at Gonzaga University, said he often looks for research to inspire his students. That’s how he found Bergdahl’s work about beetles and ice crawlers.

“It’s nice to have something that’s close by and represents the unknown,” Chang said. “It is definitely something that inspires curiosity.”

The future of Grylloblatta doesn’t look great. Scientists believe they are at significant risk from climate change.

“If the snowpack would disappear from these sites, it would be catastrophic for these populations,” Schoville said. “If you value nature and you value the idea that someday your children could go out and view this species, that’s your reason to protect them.”



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