clock menu more-arrow no yes

Filed under:


An exquisite specimen of natural engineering shone in the morning brightness, hanging stationary in a chalky-blue sky at the Wedge Overlook.

After a while its builder - a spider the size of a gnat - pounced from the center of the web and bound a minute insect to the strands, then ambled swiftly back to the vortex of that fragile but amazing construction.I had snuggled under a waist-high juniper to get out of the sun's heat, which was already bothersome by 9 a.m. Glancing up between the shaggy gray trunk and a scabrous branch, I noticed the web.

The main section was circular, about 4 inches across, and the concentric circles of webbing seemed to be repeated a couple dozen times. The circles were held in place by radii, probably three dozen of the spokes.

A large ant hiked up the juniper, and for an instant as it went into the sunlight the gray insect turned red in the light, hairs bristling, then was back in the dark.

Stretching from the circular portion of the spiderweb were anchoring guywires, crossing space and attaching to juniper twigs.

Beyond the disk, they formed a pattern like a handkerchief with stretched corners. More of the less-than-hair-wide wires ran from the edges of the circular net to the main anchor lines.

It was hard to count the guywires because the web had to shift into the right angle with the sun or they were invisible. But for moments the whole construction would be shining in the sunlight.

Then I could see that the main support lines ran across the entire network of webbing to tie up on twigs, sometimes continuing beyond to another twig; the side supports only went as far as the guywires.

The web certainly didn't look gossamer - it was more like steel, some amazing high-tech sort that was so powerful, flexible and strong that when it billowed out with the breeze or sucked in, then returned to flatness, it retained the precision of its architecture.

A wonderful elasticity ensured that nothing was damaged or sagging out of shape when the silk moved. It continually shifted. Sometimes it puffed into a ra-diotelescope shape, sometimes curved like a boat's sail.

Now another insect hit - bang! the spider got it. I could see the victim's wings stick out and the spider's tiny legs moving up and down as it lined up another meal.

The spider was so tiny, just a dark mass, that at first I had thought it only a bit of debris in the middle of the web. After striking, it would return to wait, feeling for a bug's uneven vibrations in the silk, like a fisherman with a line in the pond.

As the sun climbed, the colors reflected from the web's lower portion changed. At first they were yellowish, and then they tended more toward the blue end of the prism. When the wind shifted, I could see reds toward myself, then blue tones to the upper right - a changing, shimmering play of color.

The webbing nearest to my face caught the light, an iridescent reddish film, almost a moire pattern, distorting light itself.

For a time this refraction image looked like a continuous surface, like a soap bubble, rather than many individual strands.

How did the spider anchor the web up there in the first place? Lying under the bush, I thought it might have lowered itself from some higher branch.

I got up from my rubber backpacking sleep mat and stood over the little web. From that angle, the spider was illuminated - a minute greenish-yellow crab with mandibles in front, a black triangle on the rump. From there, with the backlighting, I saw many more concentric circles in the web, which came tightly together in the center.

From here I could see that the thread at the top, from which the whole contraption hung, went from highest point to highest point of the juniper. About a foot long, it reached horizontally across empty space between branches.

How could the spider make the connection across that gap?

If humans were constructing a suspension bridge over a canyon, the first line would be attached to a high point; someone would climb down into the canyon and hike across while playing out the wire, then scale the other side and pull it taut. Impossible for a spider, because the thread would get gummed up as it went.

Maybe it waited until the breeze was strong enough and let the wind waft it over the gap. That was hard to imagine. It was mysterious.

Then I thought, what could be more mysterious than the creature's behavior, anyway? How could such a microbrain carry out the intricate design of its web? The spider is a miracle of programming; how many generations of trial and error were required?

Consider nature's joy, working through the ages.