strange behaviors

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  • Richard Conniff writes about behavior, in humans and other animals, on two, four, six, and eight legs, plus the occasional slither.

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Five Ways Real Spiders Spin Webs Around Spider-Man

Posted by Richard Conniff on April 29, 2014

Wheel spider (Photo: hamariweb.com)

Wheel spider (Photo: hamariweb.com)

My latest for Takepart:

You remember that seminal scene in the “Spider-Man” story where young Peter Parker gets bitten by a radioactive spider? It is of course the event that turns mild little Parker into the celebrated web slinger. And in case you have somehow forgotten, despite endless repetitions in movies, television shows, video games, and theater, yet another version, The Amazing Spider-Man 2, will descend on unsuspecting moviegoers May 2.

dick-at-zooIt reminds me of a turning point in my own life, though I don’t normally identify much with superheroes. My father was a journalist, and one day when I was about 12, he took me along to New York City’s Staten Island Zoo. There veterinarian Patricia O’Connor introduced me to a year-old chimp, which reached out cordially, or so it seemed, to shake my hand. My father captured this endearing scene in a photo, which subsequently appeared with his article about zoo veterinarians under the headline “Physicians for Fang and Fur.”

Then, immediately after the photo was taken, the chimp leaned over and sank his teeth into my arm. And, need I say, NOTHING WAS EVER THE SAME.

OK, I didn’t develop a magical ability to swing through the trees or, chimpanzee fashion, hurl shit at the heads of approaching strangers. But I became a writer about wildlife. Same thing, almost.

As a result of that life-changing moment of infection, I have often tried to see the world from the point of view of the animals I am writing about. And at one point, for a National Geographic assignment about spider webs, I actually attempted to become a web slinger. I strapped on climbing gear and ropes, looking a bit like Charlotte’s Web meets Rambo. Then I set out to weave my web 15 feet above a concrete floor in the corner between two climbing walls at a YMCA. You can read the gory details in my book Swimming With Piranhas at Feeding Time: My Life Doing Dumb Stuff With Animals. But here’s the bottom line: Spiders have a magical ability to pull silk out of their butts. People don’t.

That assignment made me realize that all the bogus special effects in Spider-Man movies cannot come close to what real spiders do every day. With that in mind, here are five examples to make the latest Peter Parker weep:

1. While hanging from a trapeze line, a spider in Colombia uses its silk to make a sticky ball at the end of a thread. By mimicking the perfume of a female moth, it lures male moths into the area, where it beans them in midair with the ball, then reels them in for dinner. William Eberhard, the Universidad de Costa Rica biologist who discovered the species, recorded nine hits in 21 attempts. He named the species Mastophora dizzydeani,in honor of one of the greatest baseball pitchers of all time, Jerome ‘Dizzy’ Dean.”

2. Europe’s water spider spends its whole life underwater, using its web to form a diving bell, which it anchors in place with a thread. The spider darts out to catch and eat anything that touches the web, mostly insect larvae and copepods. It also rises to the surface occasionally to trap air bubbles in its hair and carry them down to replenish the supply in its diving bell. For mating, the male builds a diving bell next to a female’s diving bell, then weaves a tunnel to connect the two.

3. In Mexico, a tiny web-building spider (Chrosiothes tonala) has adapted to feed on a highly unlikely prey: termites that nest underground. According to Eberhard, who first described the behavior, the spider waits on a horizontal line several inches above the ground, in an area where parties of worker and soldier termites are likely to come out onto the forest floor briefly in columns to forage. Apparently alerted by a chemical cue from the termites, the spider begins to drop to the ground as often as seven times a minute, searching for prey. Her descents are “blind,” and most are failures. If she is lucky, she lands on a column. But instead of attacking the first termite that she encounters, she attaches an anchor line to the ground and uses it to draw the horizontal line tighter and closer to the ground. Then she returns to the column of victims, biting one and tossing silk over its head like a hood. The first three or four victims pop up off the ground and hang in midair by a thread from the horizontal line. Later victims—up to 20 at a time—remain attached to the ground until the spider finally severs the anchor line and pops all of them into the air. Then, the spider casually rolls its prey in a ball and hauls off as much as 24 times her own weight in dead termites.

4. For a spider, the worst nightmare is to be attacked by a parasitic wasp. These wasps lay their eggs on the spider and inject venom that puts the spider in a coma. When wasp larvae emerge, they eat the spider alive. The peril is particularly intense for the wheel spider (Carparachne aureoflava) in southern Africa’s Namib Desert, because there’s no place to hide. So when it’s attacked, the wheel spider flips on its side and escapes by rolling down the dune at up to 44 rotations per second. (Check out the video.)

5. In Costa Rica (the remarkable Eberhard again), a spider makes a traditional orb web and then, by running a line back from the middle of the web to an anchor point, tightens it into the conical shape of a satellite dish. Some flying insects are clever enough to spot a web and back away at the last moment. But this spider simply cuts the anchor line, and the web springs forward to entangle the escaping victim.

What does all this add up to? I haven’t seen the latest Spider-Man movie, so maybe I’m just being cynical. But I’m betting that Hollywood moguls will turn out once again to have less inventiveness and artistry than your average house spider.

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