A new study revealed that female dragonflies literally “play dead” to avoid non-consensual mating. This phenomenon was noted among the females of the species as they were trying to lay eggs. Although not the first preventive measure, this seemed to be one of the most effective.
Research was carried out by Rassim Khelifa, a Ph.D. student at the University of Zurich, part of the Department of Evolutionary Biology and Environmental Studies. A paper with the study results was published in the journal Ecology.
Female Dragonflies Feign Death To Fend Off Stalkers
Back in 2015, Khelifa traveled to the Swiss Alps to collect and study moorland hawker dragonfly eggs. He had set out to establish the possible effects of climate change on this species. During his observations. Khelifa also noted an unusual behavior.
Moorland hawker dragonflies mate in the summer and use vegetation both as a support and cover. As a first protection strategy, female dragonflies choose a plant-concealed place to lay their eggs. However, they have to fly to and from the site, which is when other males can start stalking them.
As such, the females then turn to their second method. More exactly, if followed by one or more aggressive males, the female dragonfly crashes into shrubs or to ground. As they feign their demise, they continue playing dead until the hovering males decide to leave. Then, the “fallen” specimen gets up and about with her work.
Khelifa observed a total of 35 female dragonflies for his study. 27 out of them tried to feign their death, and 21 succeeded. Most of the specimens to employ the technique seemed to prefer a dense population to the open ground.
Males rely on color and movement to detect the females. As such, the thicker shrubbery offers an even better cover. Khelifa offered a possible explanation for this decisive behavior. He said that:
“When a male copulates with a female, it first extracts the sperm of the previous male. This can damage the reproductive tract of the female. So, multiple mating is not advantageous for the female.”
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