Friday, September 5, 2008

Our Spider Walk, or, Finding Wolf Spiders at Night

Last night my husband and I went on a Spider Walk lead by a biologist at the University of Akron. It took place at the UA Field Station which is located on the Bath Nature Preserve in Bath, Ohio.

It was lots of fun and very interesting. I only got creeped out when we went into the woods to find a certain kind of spider and our flashlights revealed spiderwebs all over the place! Wherever you turned! Including one of an especially large and bulbous spider (please don't ask me to remember its name) which my husband spotted and the biologists actually collected (along with its suitor) to take back to the lab in order to get silk from it.

While still out in the field, though, I learned something very interesting (and lots of fun!). It was how to find wolf spiders at night. You do it by the glow of their eyes. If you search correctly, you'll see their eyeshine as little green, sparkling diamonds in the grasses. It's true! Try it! Like this:

Wolf spiders can be found at night by using a headlamp to see their eyeshine. Relatively few spiders have eyeshine.
At night, wolf spiders can be collected by taking advantage of their eyeshine. If you hold a flashlight or a headlamp up by your forehead, the light from the flashlight will reflect off of the tapetum located in the eyes of the spider (much as a cat's eyes reflect light).
The picture and quote above are from this page in the Wolf Spider Directory website.

You'll be surprised how many little sparkling green diamonds there are all around you! We learned lots of other interesting things too, about webs and silk and spider behavior and such.

Do I like spiders? No, not really. But it was really fun walking around in the dark looking for webs with flashlights and to have a biologist whose specialty is spiders and spider silk on hand to answer questions. And surprisingly (or maybe not) I had lots of questions. Here are some of the things I learned:

1) There are two goats in Canada which have been genetically engineered to produce spider silk proteins in their milk. They were supposed to help in research that would lead to being able to extract the proteins from their milk and spin them into silk fiber. The company that produced them was sold and the goats are now just hangin' out with nothing to do.

2) Spider silk has antimicrobial properties. That's probably why in olden days some people would put cobwebs on cuts or wounds.

3) Spider silk will contract with surprising force when it gets very wet. Perhaps another reason that it would make a good bandage, the more the wound bleeds, the wetter the silk gets, causing it to contract, perhaps helping to close/cover the wound.

4) Spider silk is ounce for ounce stronger than steel, but you won't find bullet proof vests made out of spider silk. Such a vest would indeed stop a bullet, but only after it had already passed through you. It turns out that spider silk is extremely elastic and stretchable.

5) Spiders can produce lots of different kinds of silk. Most of the sticky kind is wet-sticky, but there is one kind of spider that we saw whose web is sticky in the same way that a gecko's feet are sticky. The silk spun in the web is so fine that the stickiness is caused by Van der Waal's forces. That's attraction at the molecular level!

6) Most spiders live in a world of vibrations. That's how they know what's going on in the world and what kind of prey is in their webs.

7) All spiders produce silk.

Those were some of the interesting things that I learned last night. I had lots of fun. The next thing over at the Field Station will be a Fungus Forage. I'm looking forward to it!

No comments: