Dance of the Peacock Spider
❂ Doing the Y: Only 4 mm in size, the Australian male peacock spider (Maratus volans) puts on an impressive courtship display, rivaling the Village People in Peacock Spider Dances to YMCA . Described by researchers as multi-modal, the dance includes 3rd leg waves, synchronized unfurling of colorful belly flaps, abdominal bobbing and pedipalp flickers. As if these visual displays were not enough, the spider generates bursts of vibrations carried through the ground to signal his passion for his lady love.
❂ Darwin’s Dilemma: Is there an selective advantage to such complexity? How did it evolve? As the rituals get more elaborate, there may be diminishing returns given the limitations of biological cost and sensory perception. Translation: is it a waste of time? 🙂 But studies show that redundant signals allow our spidery suitor to adapt to varied environments. Too dark to see the colorful fans? The seismic display compensates for lack of light.It is thought that each signal carries a different message for the female to evaluate. It’s also an exercise in self preservation: males risk falling prey to the cannibalistic tendency of the female spider. Web building male spiders generate shudder vibrations that measurably calm the female’s aggression. Others present a silk-wrapped nuptial gift that distracts the female long enough to get the deed done. An unusual tactic called thanatosis is to is to feign death when the female shows signs of terminating the romantic act. Once the female has dragged off the motionless male, she begins to feed on his nuptial gift upon which the male quickly revives to resume mating!
So humans, do you see any parallels in strategy? Perhaps, you too met your mate on the web?
▶Nuptial gifts: http://goo.gl/VCsbzN
▶Spider Shudders: Male courtship vibrations delay predatory behaviour in female spiders. Wignall and Herberstein (2013) http://goo.gl/wT29bD
▶Dance Moves: Multi-Modal Courtship in the Peacock Spider, Maratus volans. Girard et al. (2011) http://goo.gl/SlIK1E
▶Gifs: via http://biomorphosis.tumblr.com/