ENHS Nature Trails May 99 Article 3

Report from the Nature Hut: your questions answered!

This year the Eugene Natural history Society sponsored a "Nature Hut" at the Kids Park at the Lane County Fair. It was a hit with the children, who especially enjoyed the live animal demonstrations. The "Please Touch" table is a perennial delight. This year the "Nature Hut" was co-sponsored by the Mount Pisgah Arboretum.. Thanks go to Michelle Wood, coordinator; chief helpers Melody Clarkson, Fran Rosenthal, June Smith, Dave Wagner and Marge Zane; and all the dedicated booth sitters. There was a pad kept in the booth for people to write questions. Following are responses prepared by the editor.

Where are some good locations to take my children to look for fossils?
Our suggestion is for you to first take your children to the U. of Oregon Museum of Natural History. It is located at the corner of 15th and Agate St. in Eugene. There you can see some nice displays of Oregon fossils. Then, go into the museum bookstore pick up the book on Oregon fossils written by Prof. William Orr and his wife Elizabeth. It is full of good sites.

What causes the dark coloration on deer teeth?
Deer are exclusively vegetarians. They eat only plants, they eat a lot of plants. Many of these plants contain tannins and other substances that stain tooth enamel. The teeth of deer are often as badly stained as the teeth of a person who chews tobacco all the time.

How do you get the spider web on the black paper?
Capturing spider webs is an ancient craft with many possible techniques. The web on the Please Touch table at the Lane County Fair was prepared using the wonders of the modern spray can. The equipment needed to make these preparations is simple: a piece of smooth black paper, a spray can of white paint, and a spray can of photo adhesive.

First, locate a suitable web. Garden spiders produce the best, with an attractive design stretched across open and thus accessible spaces. Study the web closely, paying particular attention to the attachments. Most webs have only the minimum of anchoring strands, three. A few have four or more. Those with three are best because with three the web is always in a single plane, perfectly flat. But the others can produce very appealing pattern variations. Sunrise and sunset are good times to observe spider webs because the low angle of light can make a web glow against a shaded background. In the fall, dewy mornings do the trick. Walk around to be sure you can locate the anchoring strands from any angle and note obstacles to reaching behind the web. It is important to be able to approach the web closely from both sides without disturbing its anchors.

Second, flick off the spider. There's no reason to kill the spider for this. The spider is used to having its web brushed away under natural conditions. Spider webs are, after all, very fragile. Even a blundering moth or a heavy falling leaf can destroy the arachnid's prize. If you are careful about removing the spider it will return later to make another web with little lost. Just don't keep going back to the same spider. Anyway, if you try you will find that spiders remember very quickly where their webs are repeatedly destroyed and learn to build them out of harm's way.

Garden spiders tend their webs from the very middle. If they are not to be poisoned with white paint or adhesive, they need to be gotten off the web before it is sprayed. You could always scare the spider off by poking at it with a stick but many are prone to run only a short distance and you'll have to poke it again. This poking is likely to damage the web so I prefer to flick the spider off with a snapped finger. Note on which side of the web the spider is sitting and flick it off from the opposite side with a brisk, controlled snap of the finger. With practice, both spider and web are left undamaged.

Third, spray the web with white paint to enhance its visibility. Use light, quick strokes from about sixteen inches away. If you are out in an orchard with a web in wide, open space, that's all there is to it. Spray paint dries in the air and what doesn't stick to the web passes through and falls harmlessly to the ground in a couple of feet. If the web is close to your house, however, it is necessary to get an assistant to hold a newspaper screen behind the web to catch the paint that goes through. Otherwise, you might get paint on the side of the house, on bushes, or other places where it will not be appreciated. You want just enough white paint on the web to make it stand out but not so much it forms droplets on the fine cross strands. The finer the spray the better. Only practice and self-correcting experience will give you the skill to do this part right.

Fourth, spray adhesive on the web on the other side from which the paint was sprayed. Use your knowledge of where the anchor strands are located to keep from damaging the web if you have to reach around behind it. Pay attention to where the pass-through spray goes. If necessary, use the same precautions as described for the paint spraying. Again, what you want is a thin, even coating.

At this point you need to work swiftly yet carefully and deliberately. With a smooth move, bring the black paper into even, flat contact with the adhesive-coated side of the web. Hesitation is a ticket to disaster and haste will give the same ride. Plan the direction of the move carefully so the anchoring strands and any other obstacles are avoided.

Bring the paper right up against the web, blowing the web into the paper if necessary to gain contact. Remember, the adhesive binds instantly and second chances are nonexistent. Hold the paper still, against the web, for a minute to allow the adhesive to set up. Carefully break each anchor strand, one at a time, holding on to the loose end so it doesn't snap back and collapse the web on your paper. The natural springiness that keeps the web taut needs to be remembered. Fold each anchor strand around onto the back side of the paper where the adhesive can catch it. Pinch this wrap at the edge of the paper to tack it down. When the last anchoring strand is attached, you are done!

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