Floating around on the Beagle, miles from shore, Charles Darwin observed spiders as they wafted on a breeze and onto the ship and was perplexed. How could a species survive that had so little control over its destiny?
As it turns out, those seafaring spiders may not have been blowing about at the mercy of the wind, but using it but intentionally “flying” through the air to meet the father of evolution theory.
Studies have found some spiders can travel up to 30 kilometres using wind power, and what’s more, they can control the direction they travel using a technique called ‘ballooning’. This involves using their silk to catch the wind, which then lifts them up into the air.
As if that wasn’t enough to give you the creepy crawlies, a new study published in the journal BMC Evolutionary Biology has found spiders are not only accomplished ballooner but excellent sailors as well.
A joint research team including Morito Hayashi from the Natural History Museum in London, collected 325 adult spiders belonging to 21 common species from small islands in nature reserves in Nottinghamshire, UK.
The spiders’ behavior was observed on trays of water in reaction to pump-generated air, and this was compared to their reactions on dry surfaces.
Many of the spider species adopted elaborate postures, such as lifting up a pair of legs, to take advantage of the wind current while on the water surface. This allowed them to “sail” in turbulent, still, fresh, and salt water conditions.
By releasing silk on water, the sailing spiders were also able to drop anchors to slow down or stop their movement. This suggests the silk may sometimes work as a dragline for the water-trapped spider to attach to floating objects or to the shore.
Species of spider that had learned the ballooning technique were better sailors than non-flying spiders.
It’s believed these skills have helped spiders find and colonise new territory and survive extreme events like floods.
How does this discovery affect the way you feel about spiders?