Showing posts with label spiders. Show all posts
Showing posts with label spiders. Show all posts

July 08, 2015

Spider photographer and collector’s legacy lives on

By Rod Crawford

Many people try to avoid spiders, but spider enthusiast Bob Thomson sought them out and collected them for the Burke Museum—contributing more than 9,000 specimens and hundreds of photographs! So when I heard that my old friend and colleague had died, I thought his story should be shared, and put together the following from my recollections and with some help from his son Jonathan.

Bob's son, Jonathan Thomson, captured this photo of his father in Sumatra. 

April 13, 2015

So this spider walks into a pine cone...

By Rod Crawford

Euryopis formosa spider in pine cone, July 10, 2011,
Thunder Lake, Yakima County, Washington.
Photo: Laurel Ramseyer.
On a sunny day in late May 2008, I went on a spider collecting field trip to Swauk Prairie outside of Cle Elum, Washington, with Laurel Ramseyer, a friend and field volunteer. The weather forecast called for "breezy." We'd have called it downright windy!

It was difficult to collect spiders with the wind blowing away anything loose and exposed. I did manage to sift nine spider species from hawthorn leaf litter, but only swept six species from the rippling sea of grass. Laurel had similar troubles.

Then Laurel saw a spider run into a large fallen pine cone (probably to get out of the wind), so she picked up the pine cone and started to whack it inside her net in an attempt to collect the spider. It worked! We were in a Ponderosa pine woodland with a lot of pine cones so she continued whacking more cones and eventually added three good species to that site's spider list.

This small beginning led to a major obsession for Laurel and she began using this method at other sites. To date she has whacked nearly 7,000 pine cones inside a heavy-duty net held against her leg, looking for the pine cone spider fauna that she, in a sense, discovered. Laurel (with a little help from me) collected 1,060 spiders from 4,600 eastern Washington pine cones between 2008 and 2013. I identified the spiders and added them to the Burke's collection.

Laurel sorting a pine cone beat sample, May 18, 2011,
Moloy Road on Wenas Creek, Yakima County, Washington.
Photo: Rod Crawford.

As it turns out, no spider species were previously recorded as collected from pine cones. Discovering a new spider species is relatively common, but discovering a whole new spider habitat—that's really something!

Some spiders evidently live in pine cones long-term, while others just use them to molt, lay eggs and rest when not out hunting. Or they wander in at random like that first one Laurel saw back at Swauk Prairie.

Euryopis formosa spider on pine cone scale, June 4, 2011,
Teanaway Campground, Kittitas County, Washington.
Photo: Laurel Ramseyer.

The spider we most commonly found in Washington pine cones was Euryopis formosa, a beautiful creature with a dark heart shape inside a bright silver patch on the abdomen. Sampling pine cones more than quadrupled the number of E. formosa specimens in the Burke spider collection—it was found at 47% of sampling sites!

This was the first study to describe the spider fauna of fallen pine cones and now there are 89 species recorded in our published paper, including two species never found in Washington state before.

Spiders are everywhere—even in pine cones!

Pine cone with spider web, June 22, 2011,
Thirteenmile Creek, Ferry County, Washington.
Photo: Laurel Ramseyer.

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To learn which spider species use fallen pine cones, read our study published in Western North American Naturalist (PDF). 

Interested in more about arachnids? Read other Burke blog posts by Rod or check out Rod's Spider Myths website for myths, misconceptions, and superstitions about spiders.

October 01, 2010

Q: Are there more big spiders now than usual?

The Burke Museum partners with the Seattle PI's Big Blog to answer commonly asked questions about the natural and cultural history of our region. Read past entries from the Ask the Burke column here.

The following was posted to the Seattle PI's Ask the Burke column on Oct. 1.

Q: Are there more big spiders now than usual? I seem to be constantly running into webs on my outdoor walks.

A: (From Rod Crawford, curator of arachnids at the Burke Museum)

This answer is specific to the Seattle area; different places have different spider species with different population cycles.

The spiders you're "running into" are mainly one species of non-native orbweaver: the "cross orbweaver" Araneus diadematus, which is native to Europe (first record of a cross orbweaver in Washington is 1927). Orbweavers are the spiders that make orb webs, and are the only spiders that do so. They are not dangerous to humans. The population dynamics of this one species are far from typical of all spiders. The vast majority of spiders actually "lay low" in August and September because of low moisture availability in their habitats.


So, are cross orbweavers more abundant this year than usual? Well, I've been working on spiders at the Burke Museum for 39 years now... and every single year I've had someone ask that question! They can't be more numerous every year than every other year, but populations do have ups and downs within individual neighborhoods. Beyond that, I think the biggest factor is that once your eyes begin to notice spiders (which are always common), you're naturally going to notice them everywhere.

To find the answers to more frequently asked questions about spiders, visit our Spider Myths website.

September 09, 2010

Q: How dangerous are spiders to humans? Should I be scared about the spiders in my house?

The Burke Museum partners with the Seattle PI's Big Blog to answer commonly asked questions about the natural and cultural history of our region. Read past entries from the Ask the Burke column here.

The following was posted to the Seattle PI's Ask the Burke column on September 8.

Q: How dangerous are spiders to humans? Should I be scared of the spiders in my house?

A: House spiders prey on insects and other small creatures. They are not bloodsuckers and have no reason to bite a human or any other animal too large for them to eat. In any interaction between spiders and larger creatures like humans, the spiders are typically the ones to suffer.

Although almost all spiders are venomous, very, very few spider species have venom that can harm humans, dogs, or cats. The purpose of spider venom is to subdue the spider's prey, almost always insects. In brief, it's an insecticide. Spider venom does not exist to harm creatures, like humans, which are too large for spiders to eat, and in nearly all cases has little if any effect on humans.

A minority of spider species have venom that can cause localized pain in humans, like the venom of bees or wasps. Of around 50,000 spider species known, only about 25have venom capable of causing illness to humans. These species are called "medically significant" spiders. In most parts of the world, such as the Puget Sound area, no spiders with medically significant venom have much chance of being found in houses.

To find the answers to more frequently asked questions about spiders, visit our Spider Myths website.

Interested in spiders and insects? Come to Bug Blast at the Burke on Sunday, September 19!

October 27, 2008

Check out photos from Bug Blast

This years' Bug Blast was a huge success! Over 1,200 people attended the event, making it the most visited Bug Blast to date. Thanks to all those who took part in the festivities, especially those brave enough to sample the cooked bugs.



June 19, 2007

Field Work Doesn’t Always Work Out as Planned

Posted by: Rod Crawford

Spider curator Rod Crawford shares the ups and downs of one of his latest field adventures...

My most ambitious (and, with the price of gas, expensive) spider collecting field trip of the year was to be a Memorial Day Weekend expedition to northeast Washington, in collaboration with Larry McTigue, an old friend from my caving days who wanted to hunt for new caves in the limestone deposits. The plan was to start in southern Stevens County and work our way north to really high quality areas near the Canadian border toward the end of the weekend. That was the plan...

Saturday went well for me. I got a much-needed supplementary spider sample from a beautiful spot in sagebrush country on Sinking Creek southeast of the town of Wilbur. Then we wasted a lot of time hunting for a gas station in Wilbur: population 1400 and all 3 of the stations out of business! But we finally made it to Hunters along the Columbia River where, at a site with meadow and pine forest, I got 20 species in a couple of hours including one jumping spider completely new to me. Meanwhile, Larry was searching for a lot of limestone shown on a geologic map, and finding very little of it. We found a decent campsite and went to bed with the moon out —

—to wake up with rain pattering on the tent. Not much, just enough to make the vegetation too wet for spider collecting. The sun came out later but it was noon before I could sweep any grass or beat any bushes. Our morning plans centered on an area northeast of Chewelah where a place called Johnson Lake looked promising for spiders and a place called Limestone Spring drew Larry like a magnet. But there turned out to be no rock of any kind at the spring (let alone limestone) and by the time Larry returned to the lake to pick me up I only had 18 species or so. It had been a pleasant morning, though, with a deer joining me for a little grazing while I chased wolf spiders, and Larry hung around while I sifted conifer litter to get the sample up to a barely adequate 21 species. Then we tried to exit back to the highway via a short cut. Who would have expected a fence right across the road? So it was backtracking through many miles of intricate logging roads for us before we could head north.

Heading north, as it turned out, right into a series of thunderstorms! Every place we tried that afternoon was wetter and less productive. The final indignity was Rabbit Mountain, which (if dry) would have been great for spider collecting. The road around the base of the mountain was a series of giant puddles that would have stopped anything but Larry's 4WD pickup. The road up to the ridge crest was blocked by a man and his daughter cutting firewood from a tree he'd felled right across the road. He told us the road only went another hundred yards and we might as well turn back. We waited him out and proved him a liar by going at least another mile along the ridge, but all in vain. The rain wouldn't stop, in fact it became a steady downpour, and the brush was so thick that the only way Larry could have found a rumored pit would have been by falling into it. And the rain seemed to positively encourage the local mosquitoes. Finally we'd had enough and decided to head south and (we hoped) out of the rain.

Well, we finally did get out from under the clouds, but the landscape was still wet by the time we camped on a soggy hilltop north of Spokane where I needed another supplementary spider sample. The sky was clear and the moon out when I crawled into my tent. During the night a very cold wind came up, and it was overcast and very wintry-feeling in the morning. I did manage, though, to get my tent packed and 7 spider species collected before it started to rain. Then the rain started to turn to sleet! Was this May 28 or were we in a winter time warp?

At this point the central Washington desert started looking very good indeed to us. The backup plan was to go to Dry Falls and take a trail I knew of down into Grand Coulee. All well and good except that when we got there the trail was blocked by a big steel bar with "Trail Closed" sign. However, it was warm and dry and that felt like a big plus just then. With about 10 hours of daylight and no clouds visible to the north, we drove north into Ferry County to try to salvage something from our last day in the field. The first place we tried had spiders but no limestone. The second place had limestone but no spiders. Finally in the early evening I got another good supplementary sample from the Curlew Lake area. Then for the long, long drive home. The upshot of the trip was better for me than for Larry; I at least got 5 valuable (if small) spider samples, while he found nothing. But the big collecting plans for those enticing spider habitats near the Canadian border remained just unfulfilled plans. Can't win them all!

For more on this year's spider collecting trips, see the Spider Collector's Journal.

Photo: Female Evarcha proszynskii from Wolfe Camp Road by Rod Crawford

May 02, 2007

Spider collecting trip

Posted by: Rod Crawford

Burke spider curator (and author of Spider Myths!) Rod Crawford takes us along on a recent spider collecting trip…


So far this year, every time I had a chance for a spider collecting trip, it rained. But bad luck doesn't last forever. The atmosphere finally became cooperative in mid-April and local natura
list Laurel Ramseyer (recently arrived from Michigan via Massachusetts) wanted to find out what spider collecting was like. Our first joint site was Stone Quarry Canyon south of Ellensburg, a secluded place that I'd found using the great online map and photo resources now available. A washout in the dirt road forced us to walk, not a bad thing with meadowlarks singing and diverse wildflowers in bloom. Starting down the canyon, we were greeted by wolf spiders racing around in the just-turning-green early spring meadows.


The little tree clump (isolated among miles of sagebrush) that I'd found on aerial photos turned out to be Douglas maple, a nice surprise; I'd expected more common trees like cottonwood or pine. At least three rare spider species were among those sifted from the leaf litter. Laurel helped out by looking for spiders under rocks (she says she turned over every rock on two hillsides) while I finished the sifting and worked at sweeping grass and herbs and beating spiders from gooseberry, rabbit brush, and sagebrush.

Laurel spotted the best spider of the day, Misumenops importunus (one of the flower crab spiders) lying in wait for pollinators among the flowers on a gooseberry bush. It was the first record of the species from eastern Washington! Laurel was most impressed by a large male jumping spider, Phidippus johnsonii, with a bright red abdomen, but he could see her coming and refused to be collected. I later found one in a retreat under a board at dusk.

The only humans we saw all day were two young ladies ascending the canyon on muleback an
d horseback. The natural flora and fauna of the canyon (the latter including many bees, bee flies, and beetles) all contributed to a most satisfying day. And our collections (including three species brought back alive for rearing) filled in yet another of the many blanks on the Washington spider distribution maps.

Of course, immersion in nature means encounters with not only herbivores and predators, but also parasites - cattle ticks were more common than some people would have found quite comfortable. But the true naturalist can't let such small things detract from fullest enjoyment of the first spring field trip!

More photos and other details on this trip can be seen on this album page from the Spider Collector's Journal site.
- Rod

Photos, from top to bottom:
Stone Quarry, photo by R. Crawford
Phidippus johnsonii, male, photo by R. Crawford
Misumeops lepidus on a balsamroot flower, ready to embrace a bee, photo by L. Ramseyer

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