Spiders are incredible engineers. This is a slow motion and normal speed close-up movie of a common garden spider building a web. I thought the web-building process was amazing before I grabbed my camera--but even more so after I slowed down the footage to 10% of normal speed! So fast and efficient is this spider as it extracts silk from its abdomen, shifts its grip on the silk fibers from claw to claw, measures distances, and creates just the right amount of tension to keep the web taut. And the third leg from the front on the spider's left side appears to be missing it's foot! Of great interest to me was how the spider attached the silk fiber at each junction.
After a little research on "How Things Work" at http://tinyurl.com/3vewxjk I learned that spiders make both sticky and non-sticky silk fibers when constructing a web. The non-sticky silk fibers are the radial fibers going from the center of the web to the outside edges. The sticky "cross beam" fibers are the ones that are being constructed in this film. At each silk junction a new sticky silk fiber is attached to a supporting non-sticky fiber. While watching how the spider adeptly manipulated the web, its position, tension on the silk, extraction of the silk from its abdomen, and the attachment of the thread at each junction, I was filled with wonder! So, I decided to slow the motion to 10% of normal speed so I could better see the details.
At first I thought the spider tied some sort of a knot at each junction. However, when I watch in slow motion, this does not appear to be the case. The spider uses a claw to grab the target non-sticky fiber, and appears to attach the sticky fiber to a location below the claw. I suspect that the spider's leg has another claw or spike (hidden from view) that it uses to line up the thread and hold it in place at the junction point while it pulls the abdomen away to extract the next thread of silk. What really amazes me is how well the silk threads stick together! It looks like they are being held together by a natural form of contact cement! If any spider experts watching this better understand how the silk junction bond is formed, please leave a explanatory comment.
In case you are wondering what the white stuff that the spider is chewing on at the end, it is pieces of silk that it cleaned up from the old web that it is recycling.
Here are some technical details about this shoot: The spider is about 1" long and my lens distance varied from about 6-12' from the spider. I used a Panasonic GH2 with the stock 14 - 140 mm lens and recorded the footage at 1080i and edited it at 720p30.
Meanwhile, I also discovered that scientists have successfully implanted silk making genes from spiders into goats and are harvesting the silk from the goat's milk! The high tensile strength of spider silk combined with its flexibility and stretch ability appear to have great potential for use in many fields including medicine.
For more on this go to http://tinyurl.com/2eew8n5.