Tag Archives: spider

Arachnitecture: Season of Spiders

Oscar has once again made her summer home in a corner of my bathroom.[1]

Oscar in our bathroom. Discarded debris from his meals is below his web.

Oscar in our bathroom.
Discarded debris from her meals is below her web.

The season of spiders began here a couple of months ago, with the appearance of the first obvious webs in dark corners. Then I began having to dodge webs strung across my favorite forest paths. Now they’re all over, indoors and out, helping their owners make a living extracting bugs from their territories.

My grandmother called all spiders “Oscar” and allocated them an honored status in her home on Dauphin Island, Alabama. Oscars ate the mosquitoes and gnats that plagued us kids on our spring-break visits to her dockside ranch house. So although some of my best friends are arachnophobes, I’ve always enjoyed having spiders around.

This Oscar’s dining room is a tangle-web, an extravagantly three-dimensional array of strands that’s particularly difficult for the unfortunate prey to find its way out of. Maybe that explains why Oscar’s so healthily chubby. (My cleaning habits have nothing—nothing, I sayto do with that.)

Some of my forest spider friends, the Cross Spiders, build those familiar iridescent orb webs that catch the light so beautifully.

Cross spider's orb web Lincoln Park, West Seattle

Cross spider’s orb web
Lincoln Park, West Seattle

By autumn, they’ll drape the forest as spiders grow larger and need more prey.

Forest air filled with webs; look closely to see them at all levels

Forest air filled with webs; look closely to see them at all levels.
Click on the photo to enlarge.

Here’s the exquisite builder of those shimmering dreamcatchers:

Cross Spider Lincoln Park, West Seattle

Cross Spider
Lincoln Park, West Seattle

But my current favorite is the Sierra Dome Spider, who builds this wonderful Buckminster-Fullerish type of web, about four to seven feet off the ground, specially designed to capture bugs rising from the vegetation below: an angel’s tiara accidentally left behind in the forest.

Sierra Dome Spider's web Lincoln Park, West Seattle

Sierra Dome Spider’s web
Lincoln Park, West Seattle

Such a stunning home also draws romance.[2] Male Sierra Dome Spiders, dreaming of love, are attracted to females with their striking dome nests—and see how beautiful she is! That lovely orange thorax, those delightfully translucent blue legs!

Sierra Dome Spider

Sierra Dome Spider

But after their romantic encounter, he’ll then destroy her nest by rolling all those carefully placed threads into a ball, to keep other males from sniffing around. She has to rebuild the whole thing, strand by strand, in order to feed herself.[3]

Tangle-webs, orb webs, dome webs: three different architectures, each tailored for what its builder needs. But there are a few essential functions they all have to fulfill. They have to be able to trap prey and hold it long enough for the spider to get there. They have to hold the weight of the spider. They have to be able to stay basically intact under the influence of a struggling bug, and as the spider wraps and removes her prey. And they have to be strong enough to withstand wind and rain.

Cross Spider with wrapped prey

Cross Spider with wrapped prey

Look at her web after she’s trapped and removed prey. It’s full of gaps where strands have been broken.

Cross Spider's orb web showing prey damage

Cross Spider’s orb web showing prey damage

Yet removing one thread, or even many, doesn’t cause the whole thing to collapse.[4] Spiders have developed the ability to produce different kinds of silks to serve the various functions of different parts of their web.

For instance, consider the strands that are sticky to capture bugs. Most solid materials break more easily if there’s already a surface rupture. To keep such initial cracks from developing, spiders coat their capture threads with a watery coat that lets those strands absorb vibrations more easily, giving them more elasticity. That means they can hold the prey longer, giving the spider time to get there.

Spiders’ strands also have a strange but really useful three-part response to being tugged. The whole web of threads shimmies with the prey’s wiggling (alerting the spider to its presence), holding together, but as the bug’s struggling puts more stress on the threads near it, they suddenly get very pliant, taking the stress off of more distant threads—which can then continue to hold up the web. Finally, under lots of stress, the buggy silk once again gets stiff, meaning it will break at the stress point, leaving the rest of the web intact.

On the other hand, when wind puts equal stress on the whole web (as opposed to a bug stressing mainly one thread), the whole thing stays strong. Amazingly strong, in fact: your neighborhood spider’s web can stand up to hurricane-force winds.

These architectural marvels are everywhere during this season of spiders. Even though “you’re never more than three feet from a spider” is probably one of those spider myths, there’s probably one closer than you think.[5] Thank Oscar for his excellent work next time you see her.

Sierra Dome Spider, waiting

Sierra Dome Spider, waiting



[1] I have left in embarrassing details about the state of our bathroom to show how helpful he’s being in cleaning it up for us. [back]

[2]  Apparently it works for some humans too; a realtor friend once told me back in my single days that if I were to succeed in buying that adorable quirky little cottage tucked into a Seattle greenbelt, I wouldn’t remain single for long. Although I did not buy that particular quirky cottage, I did later buy another. I did not remain single for long. [back]

[3] My companion has not yet destroyed my home, although he is planning some extensive remodeling. [back]

[4] Unlike a major bridge in my state. [back]

[5] Sorry, arachnophobe friends. [back]

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Tangled

The air itself seemed to be shimmering and vibrating. Always in favor of magic, I peered more closely to see what was going on.

The quivering was a crane fly, one of those bugs that look like giant mosquitoes but don’t actually bite or sting, whose long legs had gotten caught in the sticky strands of a spiderweb.

via Wikimedia CommonsAs the fly beat its wings with desperate speed, I waited for the spider to come scrambling out of one of the web’s anchor points to wrap it up for dinner.

The spider I’ve most often seen in this part of the park is the Cross Spider (a.k.a. the European Garden Spider, probably introduced from there). She’s a lovely creature, dramatically marked across her back, calm and focused even when a tiny tremor triggers her race across the web to wrap her prey in steely soft silk.

Cross Spider in her web

But this was no small tremble: the crane fly, low in volume but huge in spread at an inch and a half, was violently shaking the web in its effort to escape. Where was the spider?

Finally I realized that the web was torn and shredded beyond a day’s worth of meals. Like other orb spiders, the Cross Spider rebuilds her web each morning; this web’s architect had moved on, presumably to create a new one elsewhere. (Here’s a video of a Cross Spider in the process of weaving a new web on a recent morning.)

It’s hard enough to watch a creature struggle for life when you know it’ll shortly be consumed by a hungry predator, but now it looked like if the crane fly couldn’t unstick itself, it would simply die of exhaustion and starvation, unless a bird happened to swoop by and nab it. Yes, they only live 10-15 days anyway, but that means a crane-fly day spent struggling in a spiderweb is about equivalent to five years of dire imprisonment for a human. So naturally I wanted to free it, but it was too high for me to reach.

*****

Toward the other end of the hypsographic curve are other innocent creatures caught in tangled webs—webs indeed, like the cross spider’s, originally “practised to deceive,” to lead prey into a false belief—this time on the seafloor. These “ghost nets” trap vast numbers of victims, include those brilliant mollusks, the octopi.

Octopus vulgaris. Photo © Matthieu Sontag, CC-BY-SA, Wikimedia Commons

Octopi are intelligent, playful creatures. They have personalities and think conceptually; they can unscrew jar lids and create games with water toys andjuggle tankmates.

And they die in large numbers in the deadly fishing nets lost at sea, which continue their ghost-fishing mission long after they’re abandoned by humans. In the fishing ground of one Japanese coastal municipality alone, a study estimated that between 200,000 and 500,000 octopi die from entanglement in these invisible webs every single year. So do rockfish, cuttle fish, lobsters, and other finfish and shellfish. These nets can keep ghost-fishing for years before they disintegrate, if they ever do.

Yes, there’s good news—for instance, the Northwest Straits Initiative has put a lot of work into ghostbusting the lost nets in Puget Sound—but there’s a long way to go.

*****

We intelligent, playful humans are also struggling in ghost webs—for instance, of chemical sensitivity to the web of toxics woven deeply into our air, our water, our homes. As with the disused spiderweb, the chemicals were intended for other purposes, but are trapping our innocents: children and other vulnerable humans. The important work of Jennifer Lunden, Sandra Steingraber, and others in revealing this tangled web of toxicity has recently been highlighted in the New York Times, including this aptly-titled photo in a series by Thilde Jensen.

And sometimes I feel like the struggling crane fly myself, as I try to create a life of happiness and love for nature in this web of nature-denying culture I’ve been born into. How can I stay light of heart and spirit, intimate with living nature, when my feet are enmeshed in a web of car-addicted infrastructure, indoors-based education, technological communication that sucks energy from the earth, from the soul? How can I free myself from the stickiest skeins in this entangling net, those of environmental despair?

*****

When I went back to the spiderweb the next day, the crane fly was gone. I’m going to choose to believe that it finally freed itself and those tired wings found a place to rest and recover, to enjoy another few days of life.