Lucky Accident: Researchers Discover Jumping Spider’s Ability to “Hear” Sounds From Over 3 Meters Away
A new study reveals that jumping spiders, and most likely other spiders, are able to hear and respond to sound coming from a distance farther away than previously thought.
The study, published in the journal Current Biology, showed that jumping spiders are not only acutely sensitive to airborne vibrations coming from nearby sources few centimeters away but can also respond to sounds coming from sources more than three meters away.
"The sensory world of the tiny jumping spider was thought to be dominated by sight and tactile touch," explained co-author of the study Paul Shamble, who participated in the research during his stay at Cornell University and has since moved to Harvard, in a statement.
"Surprisingly, we found that they also possess an acute sense of hearing. They can hear sounds at distances much farther away than previously thought, even though they lack ears with the eardrums typical of most animals with long-distance hearing."
Shamble, along with Gil Menda of Cornell University, discovered the spider's unusual auditory sensitivity by accident. The original plan of the researchers is to make neural recordings of the spider's brain using a technique to explore how the spiders process visual information.
During the experiment, Gil started recording from an area of the spider's brain that is deeper than previously analyzed. When Gil started to move away from the spider, with his chair squeaking across the floor of the room, the neural recording made a distinct pop sound. When Gil tried to squeak his chair again, the neuron recording once again made the pop sound.
Gil showed Shamble his shocking discovery by clapping his hands near the spider. When Gil clapped his hand near the spider, the neuron once again responded to the sound. Gil tried to back up a bit and clap again and once more the neuron fired. The researchers even came to the point that they are outside the recording room about three to five meters away the spider clapping and the neuron are still responding to the sound they made.
Analyzing their discovery, the researchers found that the spider's hearing ability is most sensitive to frequencies that would enable them to hear wingbeats of their parasitoid wasps enemy. Furthermore, the researchers were able to find that the spider's sensory hair, which is responsible for responding to sounds originating from nearby source, are also responsible for registering far-away sounds.