The Burke Museum’s ‘spiderman’ searches high and low to find Washington’s arachnid species | The Seattle Times

2022-08-19 22:10:59 By : Mr. John Ren

PLUCKING PINHEAD-SIZE spiders out of leaf litter takes concentration, keen eyesight and favorable temperatures. If it’s too cold, the tiny creatures won’t move, Rod Crawford explains. And if they don’t move, you’ll never be able to spot them.

Conditions today are on the cusp, he warns me as he grabs damp duff from beneath a stand of alders and stuffs it into a garbage bag. The nastiest spring in a decade put Crawford behind schedule on spider-hunting trips, and even in mid-June, it’s still cool and drippy in this forest off the Mountain Loop Highway.

He spreads a cream-colored cloth over a bare patch of ground, then lowers himself onto the dirt. Recumbent, he tosses a few handfuls of duff into a sifter fashioned from a cat litter box with its bottom cut out and replaced by a screen. He shakes the pan, and debris rains down on the cloth.

Crawford leans in, eyes peeled for specks in motion.

“It looks like this isn’t so bad,” he says. “Here’s a nice little spider.” With a vial, he scoops up an eight-legged dot that wouldn’t scare even the most extreme arachnophobe. “People walking through a forest with dead leaves on the ground have no idea of all the life that’s right under their feet,” he says.

MANY NORTHWESTERNERS KNOW Crawford as the University of Washington Burke Museum’s “spiderman.” He’s the go-to guy when spiders are in the news or B.S. needs debunking. He gives presentations to schoolkids, answers arachnid questions from across the country and does Q&As with pest control companies, hoping to convince them spiders shouldn’t be blasted with bug spray. His spider myths page, dedicated to correcting humanity’s many misconceptions, is one of the most popular destinations on the museum’s website.

It’s not unusual to encounter giant male house spiders up to 4 inches across stalking basements and bedrooms in the fall in search of mates. Another common sighting is female goldenrod crab spiders, which can morph from white to yellow to blend in with flowers. Some female wolf spiders attach blue egg sacs to their abdomens like fanny packs, then carry the hatchlings around on their backs.

You can learn, for example, that spiders don’t crawl into your mouth at night, nor do they creep into your house via drains. If you find them in your sink or tub, it’s because they fell in looking for a drink. Another myth Crawford and others helped bust is that the bite of the hobo spider is dangerous to people.

But his true passion — and decades-long mission — is to catalog and characterize the dazzling diversity of spiders that make Washington their home. Among states with comprehensive lists, Washington ranks third in number of spider species, behind Texas and California, both of which are much larger.

The Pacific Northwest’s lush and varied landscapes abound in niches where tiny predators can make a living. Spiders thrive everywhere from rocky coasts and beaches to the high slopes of Mount Rainier. Early in his career, Crawford helped monitor spiders that were among the first animals to recolonize Mount St. Helens after its 1980 blast, ballooning in on gossamer strands of silk. The dry side of the state might have a lower density of spiders, but there seems to be just as many species — if not more — than on the moist west side, he says.

With their symmetrical webs, orb weavers are the most familiar type of spider, but Washington also is home to tarantula-like spiders that lurk in silk-lined tunnels with folding doors, waiting for unwary bugs to bumble by. Sheet-web weavers sculpt diaphanous hammocks that hang like bunting in shrubs. Then there’s one of Crawford’s favorites, Hyptiotes gertschi, the triangle spider. Females spin a web shaped like a slice of pie, pull it taut, then let go the instant an insect strikes, so the web collapses and ensnares her prey.

WHEN CRAWFORD STARTED serious spider-hunting in 1971, his mentor gave him a booklet that listed 160 species statewide. The total is now up to 964 and counting, thanks largely to Crawford and his small team of volunteers. He has discovered nearly 200 species that hadn’t been described before, many of which proved to be new to science. Of the nearly 190,000 Washington specimens in the Burke’s spider collection, Crawford contributed about half.

Rod Crawford of the Burke Museum recommends the following resources:

“Pacific Northwest Insects,” by Merrill A. Peterson, of Western Washington University, includes a short section on spiders.

The only dedicated guidebook that covers Washington is “Field Guide to the Spiders of California and the Pacific Coast States,” by Richard J. Adams and Timothy D. Manolis.

Online, Buggguide.net is a user-friendly resource for spider collectors.

iNaturalist, a cellphone app, offers crowdsourced identification, though Crawford cautions the accuracy can be questionable.

Crawford created a checklist of Washington spiders in 1988. It’s not up to date, and it’s just a list with references — no illustrations. It’s also available only in print. If you’d like a copy, email him at tiso@uw.edu, and he’ll mail you one.

Because of his efforts, that collection is now nationally recognized for its research significance, says Melissa Frey, invertebrate collections manager at the Burke. “Rod’s curatorial and research career is legendary.”

Three arthropod species were named for him by other scientists — a spider, a millipede and a spider relative called a harvestman.

But Crawford’s work is far from finished.

To systemize his survey, he divided the state into 2,195 sections of about 31 square miles each. He tracks his progress on a map by coloring in the sections that have been sampled. He’ll have been at it for 51 years this month — the Burke celebrated his golden anniversary in 2021 — and the map still has more than 1,400 blank spots.

Crawford, 70, looks on the bright side.

“I’m not going to live another 50 years,” he tells me, cheerfully, “so I’ll never run out.”

CRAWFORD PICKS field-trip sites by poring over maps, Google Earth and GIS databases. Public property is preferable. So are areas with a variety of habitats. This Forest Service land in Snohomish County, where the dirt road dead-ends at the South Fork of Canyon Creek, checks all the boxes.

Crawford starts with the leaf litter, then moves on to the hemlocks, cedars and firs that are prime real estate for Northwest spiders. The trees never lose their leaves, and the closely spaced needles create a humid microclimate where spiders are shielded from one of their biggest threats — desiccation.

Using a heavy canvas net, Crawford beats the branches with an upward motion, then sifts through his catch.

The mix includes bigger spiders, as well as harvestmen. After more than an hour of branch-beating, Crawford moves on to sifting moss pulled from the trunks of tress — another good place for little spiders.

Before the day is out, he’ll also check for spiders in wood lying on the forest floor, swing his net through a stand of tall grass near the riverbank and poke around a bridge over the creek — the type of spot where some spiders like to set up shop. Sometimes he also whacks conifer cones against the inside of his net, a technique pioneered by his colleague Laurel Ramseyer, who discovered spiders from a family never before seen in Washington hanging out in Doug fir cones near Gold Bar.

With rain threatening, Crawford works steadily for more than seven hours, stopping only to eat a sandwich and snacks. If the species count is disappointing at a particular site, he’ll sometimes keep on into the night, collecting by moonlight or flashlight.

“People like Rod really know how to find spiders,” says Jason Bond, who studies arthropod evolution at the University of California, Davis. The two researchers met in the early 1990s, when the Burke hosted a national arachnology conference, and are currently collaborating to report on a new species of trapdoor spider from Hanford Reach National Monument identified by Crawford.

Most of his field trips are one-day affairs, often requiring six hours or more of driving. Crawford is never behind the wheel, though.

He realized early on that his wandering mind would make him a menace on the road, so he relies on friends or volunteers for transportation. “The minute I start thinking about some question or problem or interesting topic, the world just disappears around me,” he says.

DURING AN EARLIER visit to his laboratory, I ask Crawford what drew him to arachnology, and he sighs. It’s his least favorite question, he explains.

“The typical tone is: ‘How did you ever get interested in …’ ” He widens his eyes, wiggles his fingers to evoke creepy-crawlies and adopts a horror-movie vibrato … “SPIIIDERS?”

The subtext is that he’d better have a good story to justify such a weird choice.

In fact, Crawford always knew he would be a scientist. As a kid, he gravitated to science topics and devoured material several grades ahead. When a high school biology teacher skipped the chapter on spiders and their kin, Crawford read it on his own, and his fascination was born.

But it wasn’t until a chance encounter in the UW library stacks with a butterfly curator that Crawford discovered the Burke and realized spiders could be a life’s work. He switched majors from chemistry to zoology, motivated in part by the prospect of breaking new ground.

“I was discovering one or more species new to the state every time I went out,” he says.

MODERN BIOLOGICAL RESEARCH largely has moved past the type of old-school collecting and classification Crawford specializes in, but it remains vitally important, says Bond. While 50,000 spider species have been identified worldwide, scientists estimate there are probably another 200,000 yet to be discovered. No one knows how many of those will blink out before they’re ever described, due to habitat loss, climate change and other threats.

“I think about collections the way some people think about libraries,” Bond says. “They represent a documentation of biodiversity.”

Every high-tech study of spider genetics, evolutionary biology, biochemistry and behavior relies on accurate identification as a starting point. “That work of understanding what species you have is fundamental to nearly everything we do in biology,” Bond says.

While many people might think they would prefer a spider-free world, the resulting population explosion of bugs would quickly illustrate an essential ecological service performed by the multitude of small predators. According to one estimate, spiders consume 400 million to 800 million metric tons of insects annually — more than the combined weight of all adults on Earth.

“Spiders are the most important land predators on the planet because of their enormous contribution to keeping insects under control,” Crawford says.

CRAWFORD’S LAB AT the old Burke Museum was a converted walk-in freezer in the basement. In the new building, he occupies a brightly lit space with a wall of windows that open onto an atrium. On the spring day I visit, he is working through a batch of specimens collected on Halloween 2021 from the Olympic Peninsula cemetery where an outlaw called the Wild Man of the Wynoochee was buried after being gunned down in 1913. Graveyards are good places for spiders because they’re open to the public and usually bordered by undeveloped land, Crawford explains.

He posts online summaries from every field trip in his “Spider Collector’s Journal.” The Halloween entry includes a picture of a tiny spider web tucked inside a raised letter “B” on a monument stone. Another image shows a wolf spider running across a grave.

Every day in the field means three to four days spent processing the catch. The work of curation includes examining and identifying every spider and transferring them into labeled, alcohol-filled vials for long-term storage. Staring at pickled spiders through a microscope might seem like scutwork, but it’s a delight for arachnologists.

“When you look at somebody sitting at a microscope, it looks boring,” says Ramseyer, who has been volunteering with Crawford for 15 years. “But when you’re the person looking through the microscope, it can be endlessly fascinating.”

UNDER WHAT CRAWFORD calls his “Rolls-Royce” scope, the features that make spiders the darlings of documentary close-ups come into focus: multiple eyes, fangs nestled in fearsome-looking jaws, the appendages called pedipalps that males use to deliver sperm to females — carefully.

Crawford never tires of the “infinite variety of color and structure” and seems bemused that so many people are afraid of spiders.

He’s convinced the fear isn’t innate but learned — from family, teachers, television and movies. “I have done dozens and dozens of programs for grade-school kids, and the younger the kids, the fewer are afraid,” he says.

Almost all spiders are venomous, but the only species in Washington that’s dangerous to humans is the Western black widow — and bites are extremely rare. According to a 2018 analysis, the United States averages six deaths a year from spider bites — less than one-tenth the number caused by dogs and other mammals. Crawford is convinced most of those deaths attributed to spiders were actually misdiagnoses.

“I would guess the average per year in the U.S. of true spider bite deaths is less than one,” he says.

Spiders get blamed for all kinds of mysterious bumps and sores, including by ill-informed doctors. In 50 years of handling tens of thousands of live spiders, Crawford has been bitten only three times, none of which amounted to more than a momentary irritation.

He offers his services as an expert witness and has seen spiders wrongly — and sometimes hilariously — accused. One woman sued her landlord because she believed a spider was responsible for a necrotic skin lesion that turned out to be caused by drug-resistant bacteria. In another case, a man fired for sleeping on the job claimed he had been rendered unconscious by a spider bite. Crawford doesn’t often laugh out loud, but retelling that story has him in stitches.

Public education is part of the job, and Crawford is convinced he’s won people over to the spider side through the decades. But the statewide census remains his top priority.

AS HE SORTS through the graveyard specimens, Crawford tells me about a field trip set for the following day. He and volunteer Ramseyer are headed to Point Roberts, a tiny smidgen of Washington state that can be reached only by passing through Canada.

The trip will require them to drive nearly 300 miles, pass through four border crossings, fill out forms and provide proof of COVID vaccination — and Crawford can’t wait.

No one has ever surveyed spiders there before.

He’ll soon be able to fill in another blank spot on his map. 

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