March 01, 2017
Reproduction in the animal kingdom can be a dangerous affair. In soon-to-be published research in the Journal of Arachnology, Susquehanna University Professor of Biology Matt Persons details the rather unseemly method some male dotted wolf spiders (Rabidosa punctulata) have devised to mate and live to tell the tale.
In every courting ritual between wolf spiders, the male is at risk of being eaten by his intended. To avoid this, Persons said some males wait for a female to choose an attractive and actively courting male. Then, once the successful male begins mating, the “loser” male joins in.
Persons admits the strategy is novel, but also lazy and sneaky.
“It has several advantages,” Persons said. “It allows males to exploit the courtship displays of more attractive males, avoid the possibility of getting eaten and minimizes getting in a fight with the other male.”
Persons happened upon this behavior several times while collecting spiders from his yard at night. Interestingly, in his 25 years of studying spiders, Persons never witnessed such mating behavior. But over the course of just three weeks in the fall of 2015, he observed it three separate times.
“It may be particularly common for this species of spider or it is possible that the population density of this spider is particularly high in this general area, leading to triad mating,” Persons said. “Ultimately, it is difficult to know how common it is. Catching spiders in the act of mating requires hours of wandering in fields with a headlamp or flashlight and a bit of luck.”
If you’re wondering how two males can mate with one female at the same time, it turns out Mother Nature has made it possible.
“Female reproductive organs are paired and male spiders have two copulatory organs, so simultaneous insertions by two different males can occur,” Persons said.
One potential drawback of embarking on a triad—it can prolong mating. Persons knows this because he photographed one on his dining room table for more than four hours.
“I have a sympathetic wife,” he quipped.
See Live Science’s coverage here.