Researchers from University of California, Berkley in collaboration with researchers from University of Louisville have discovered that the spider genus called Selenops can actually glide.
Spiders belonging to this species can control their direction in the air. It is the only species known so far that can do this. It seems that Selenops do not do this for hunting purposes, but it is rather an escape tactic which helps them to get away from threats and predators.
These spiders can be found in Peru and Panama. Selenops spiders measure five centimeters (two inches) therefore it is light and thin.
Professor of integrative biology Robert Dudley from University of California and Professor of biology Stephen Yanoviak from the University of Louisville decided to test the gliding of these spiders by throwing 59 individuals from considerable height and observe how they react during the fall.
The researchers observed how the spider spreads its forelegs wide in order to steer. In order to land where they want the spiders employ lift and drag. Moreover these insects can also flip upside down in mid-air.
Besides finding out that these spiders can fly they also made the same discovery regarding bristletails, ants, stick insects, mantids, cockroaches and katydids. What made the two scientists study whether insects can glide or not was an incident when they noticed that a certain type of ant can land on another three every time it is knocked off a branch.
Robert Dudley said:
“My guess is that many animals living in the trees are good at aerial gliding, from snakes and lizards to ants and now spiders. If a predator comes along, it frees the animal to jump if it has a time-tested way of gliding to the nearest tree rather than landing in the understory or in a stream.”
Yanoviak noted that this study raises multiple questions such as for example how acute is the eyesight of the spiders, how their hair affect their aerodynamic performance and how do they manage to target a tree. According to Dudley, being able to answer these questions could offer insight into how flight developed. They might discover that controlled gliding could have been a form of flying before wings appeared.
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