Perfect Murder, Perfect Town - Lawrence Schiller [144]
On April 2, Detective Michael Everett of the Boulder PD called entomologist Dr. Brent Opell of the Virginia State University Department of Biology, who was known as Mr. Spider Man. Opell told the police that there are two general types of spiderwebs. The first, which are called cob or funnel webs, once established are constantly reworked and added to by the spider. The second, manufactured by orb-weaving spiders, is regularly replaced by the spiders and can be completed at any hour of the day, in less than twelve hours. The police also learned that if the grate covering the window well had simply been lifted and the web damaged, the type of web would be hard to identify, but if something the size of a man had passed through the web, it would have been destroyed. Everett sent Dr. Opell an enlarged photo of the type of web in question. The entomologist said it appeared to be of the funnel type.
Six months later, on October 25, Everett traveled to Vancouver Island and met with another expert, Dr. Robert Bennett of the British Columbia Ministry of Forests. The detective had with him a newly enlarged and enhanced photograph of a the strands of the web that had covered part of the window grate. Bennett confirmed that it was a funnel web.
Photographs of spiderwebs and spiders have been used as evidence in court cases. Different types of spiders build different types of webs. The varieties of design and the behaviors associated with web-building are well understood.
Spiders hibernate in the winter in temperate zones. Boulder is definitely a temperate zone. Therefore, during winter, there is markedly less or no activity at all by the spiders normally found in Boulder.
If a spiderweb is destroyed in winter, a spider will emerge if it’s warm enough. This often happens on a warm day, particularly if the spider is in a spot with southerly exposure. Indoors, spiders are active all winter. Heat or rising temperatures produce activity. Some species are active at very low temperatures, only slightly above freezing, while others need higher temperatures to become active.
In your situation—Boulder, winter snow falling, then melting away, then falling, the weather warm enough—the spider would definitely be out.
If a web is disturbed, a spider would drop out of the web on a silk dragline, wait, climb back up the dragline, and be back where he first started from.
Again in your case, a web was broken one night when someone came by. The temperature rose the next day, and that day or thereafter, a new web could have been spun. Let me tell you a true story about a spiderweb.
In the 1600s, Robert the Bruce, one of Scotland’s national heroes, was injured and being pursued by the British. The Bruce crawled into a cave to hide. The next day the British came upon the cave, saw a spiderweb across its mouth, and figured that nobody was there. In fact, a spider had spun the web overnight. Robert the Bruce lived to fight another day.
—Robert Bennett
Dr. Bennett confirmed that if the temperature rises sufficiently, spiders can come out of hibernation. In Boulder, on Christmas night 1996, the temperature reached a low of 6 degrees, but it rose the next day to a high of 51. And the grate faced southwest—toward the sun. Perfect conditions for a hibernating spider to wake up and repair a damaged web. In October 1997 Detective Everett would learn from the National Oceanographic and Atmospheric Administration that it was impossible to determine the condition of the dew frost or snow cover on the ground around