Spider Webs for Transmitting Vibrations
TEHRAN (Tasnim) – When plucked like a guitar string, spider silk transmits vibrations across a wide range of frequencies, carrying information about prey, mates and even the structural integrity of a web, scientists found.
After two years, a research team led by the University of Oxford, in collaboration with Universidad Carlos III de Madrid, confirmed that spider webs are superbly tuned instruments for vibration transmission -- and that the type of information being sent can be controlled by adjusting factors such as web tension and stiffness.
The report in the Journal of the Royal Society Interface concludes that spider web vibration is affected by changes in web tension, silk stiffness and web architecture, all of which the spider is able to control.
Web-dwelling spiders have poor vision and rely almost exclusively on web vibrations for their 'view' of the world. The musical patterns coming from their tuned webs provide them with crucial information on the type of prey caught in the web and of predators approaching, as well as the quality of prospective mates. Spiders carefully engineer their webs out of a range of silks to control web architecture, tension and stiffness, analogous to constructing and tuning a musical instrument.
In order to study how vibrations propagate through a web, a combination of cutting-edge techniques was employed by the interdisciplinary and multinational team. High-powered lasers were able to experimentally measure the ultra-small vibrations, which allowed the team to generate and test computer models using mathematical finite element analysis. The combination of these techniques probes the links between the propagation of vibrations and silk material properties.
These new observations propose that the spider can use behavior and silk properties to control the function of its web instrument. These control mechanisms could alter vibration filtering, as well as orientation to and discrimination of vibration sources in the web.