The flight response in spiders has been honed very well over time. When disturbed, many execute escape strategies that have clearly been planned well in advance. This particular critter just drops to the ground. Sounds too simple to need an explanation? Not quite. The spider weaves a quick line of silk from the existing net and drops with it. So the spider doesn’t *fall” but freakin rappels down at the blink of an eye. If you’ve ever gone rappeling, imagine if you could spontaneously generate the rope you rappelled down on. That’s what spiders do.
Once the perception of threat is removed, the spider quickly scampers back up the same lifeline it ran down on. So not only is there a good escape strategy, but an equally sound one for getting back to the web. Otherwise the opportunity, effort and time costs of building a new web because it couldn’t find it’s previous one is just ridiculuous. Especially if the spider is jumpy.
Metadata Canon Powershot G11. ISO 80. f/2.8 at 1/60 second. Edited using Picasa 3.8 and Adobe Photoshop CS5.
Taken in November 2010 at my workplace in Bommasandra, Bangalore, India.