Skydiving spiders can land wherever they want

20 Aug 2015

As if people’s arachnophobia wasn’t bad enough already, a bunch of biologists have discovered some species of spiders can skydive out of trees.

Researchers from UC Berkeley went out to Panama and Peru to look at how spiders react to inevitable falls when frequenting high branches.

What they found was that, much like ants, certain spiders can manoeuvre while falling, ensuring that they land at the foot of the tree from whence they came.

If you’re not completely wigged out by this then luckily you’ve reached the part of this article that explains the wonderful way in which this discovery was made.

Chucking insects or flying spiders?

Robert Dudley, a professor of integrative biology at Berkeley, and Stephen Yanoviak, a professor of biology at the University of Louisville in Kentucky, packed their bags and headed south.

The duo – whose paper has been published in Interface – have been studying gliding insects in tropical forests for more than a decade, after discovering a group of ants that unfailingly land on a tree when accidentally brushed off a branch.

This led them to toss from a tree “every non-flying arthropod they could find” to see which animals glided.

That’s right kids, science isn’t all numbers and beakers. Sometimes it’s good old-fashioned insect chucking.

The lucky few

A nocturnal hunting spider – from the genus Selenops – survived the fall by gliding back towards the tree’s trunk.

Other spiders and scorpions, though, “merely plummeted to Earth”. If ever the word plummeted was apt.

“My guess is that many animals living in the trees are good at aerial gliding, from snakes and lizards to ants and now spiders,” Dudley said.

“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.”

Precursor to flight?

Dudley claims that this type of behaviour “preceded the origin of wings”, with the “wafer thin” spiders flexible enough to self-right mid-air.

The duo even saw some spiders bounce off the tree trunk, recover and successfully land on it at the second attempt.

“This study, like the first report of gliding ants, raises many questions that are wide open for further study” said Yanoviak.

“For instance, how acute is the vision of these spiders? How do they target a tree? What is the effect of their hairs or spines on aerodynamic performance?”

It’s thinking like this that ultimately feeds into modern robotics research, so how long until we have skydiving spider bots that you just can’t escape from?

Main image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic