Thursday, March 15, 2012


Above is a recent photo of Wagga Wagga in New South Wales. Although Australians are heading into winter, this is not a blanket of snow on the ground. [Arachnophobes turn back now.] It is spider silk. All of it. The area is inundated by wolf spiders (slideshow here, video here) fleeing floods that have displaced thousands of residents living along the Murrumbidgee River. The spiders are not crawling to higher ground, they are "ballooning." To do this, they position themselves on raised legs with the abdomen pointed upward, a posture known as "tiptoeing." They release several silk threads into the air and let updrafts of wind carry them away. Distance traveled will depend on the air current. Spiderlings have been known to successfully parachute 16,000' (5km) high and 994mi (1600km) away, a journey of several weeks without food. So technically, these white leavings are not webs, which the wolf spiders are incapable of producing: “Wolf spiders would rather be hiding somewhere, trying to escape birds and other predators, but when land gets so flooded the spiders are forced to flee into trees and other high things. These spiders leave behind a dragline of silk, so the spiders at these places in Australia must be nervously running into each other, marching around in search of food. There is clearly a lot of spider activity, as evidenced by the massive amounts of silk,” explains University of California, Davis, entomologist Steve Heydon. A similar phenomenon happened in Pakistan last spring. The spiders will return to their natural underground habitats when the floodwaters recede, but the good news is that they are currently feasting on the mosquitoes and other insects whose populations have boomed due to the moisture.

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