BioEd Online

It might seem a poor substitute for dinner and dancing, but when it comes to wooing the ladies, the jumping spider Habronattus dossenus at least has rhythm. Researchers have recorded for the first time the 'seismic' vibrations that accompany a male's visual display of ardour.

"Jumping spiders have very good vision, so people thought they were purely visual," says Damian Elias of Cornell University in Ithaca, New York, who captured the routine on video. Extravagant courtship dances and ornaments are common among the dozens of different Habronattus species.

Elias and his colleagues made the discovery by placing a male, together with a tethered female, on a taut nylon surface hooked up to a vibration sensor. As the male displayed to the female, the researchers observed the vibrations and converted them to a sound recording.

The thrumming buzzes and bangs, produced by the beating the abdomen against the ground, may serve to reinforce the male's visual display, made by brandishing his front legs, Elias suggests. It's unclear whether other jumping spider species found throughout North America use such seismic signals, he says - the signals may be less effective on sand than on rock, for example.

The video was one of the highlights of the Animal Behavior Society's annual meeting, held last month in Oaxaca, Mexico.