Humans are not the only being that makes use of music in courtship. Scientists have reported that spiders also create music to attract potential mates using leaves as a medium to create sound for serenading.
Alexander Sweger and George Uetz, from the University of Cincinnati, came up with a small recording studio with the aim of capturing the sounds produced by the Gladicosa gulosa, also known as "purring" wolf spider, when these insects were on different surfaces.
The research, which was presented at the annual meeting of the Acoustical Society of America, revealed that the courting ritual of these spiders involved the creation of vibration with the use of a surface, such as a leaf, for projecting noise.
The study was prompted by reports of ecologists working in the forests who claimed of hearing quiet "chorus of spiders".
For their study, the researchers placed male spiders on different surfaces and recorded the sound they made. Using the female spiders' scent cues, they were able to trigger the male spiders to purr, which they make by dragging a special organ across the surface.
The sound was then recorded and played back to the female spiders with the researchers making certain that the females were only exposed to the airborne sound and not to the physical vibrations that were produced by the males.
The researchers found that the mating ritual only works when both sound and vibration were present and when the spiders were on surfaces that vibrated easily. Their work also revealed that the spiders transmitted the sound from one leaf to another with the females picking up the vibrations.
Sweger said that the vibrations produced by the "purring" wolf spider when communicating with potential mates are similar to those produced by other wolf spider species except that this comes with airborne sounds.
Sweger said that the male spiders can only generate sound when they are on a surface that vibrates and that the female spiders only respond to the sound produced if they are in a similar surface.
"When we remove the vibration and only provide the acoustic signal, females still show a significant response and males do not, suggesting that the sounds produced by males may play a part in communicating specifically with females," Sweger said.
The researchers hope to find out if the behavior of the spiders shows the early evolution of primitive sound-based communication.
Photo: Konrad Summers | Flickr
