The female dragonflies of the Aeshna juncea species they adopt surprising behavior to avoid being harassed by males: they fake their own death. This behavior, documented for the first time by researcher Rassim Khelifa, a zoologist at the University of Zurich, represents a rare case in which animals simulate death as a strategy to escape unwanted mating attempts.
Khelifa first observed this unusual behavior while collecting dragonfly eggs in the Swiss Alps for a study on the effects of temperature on the larvae. He noticed that the females, chased by the males, they dropped to the ground and remained motionlesssimulating death.
This strategy deceived the males, who at the sight of the immobile body they gave up the chase and flew away. Once the male left, the females would get back up and they started flying againproving that they were not dead or injured at all.
An effective strategy to increase female survival
The observed behavior was confirmed by further studies conducted by Khelifa, who documented dozens of cases in which Aeshna juncea females did this to avoid mating. When competition between males was particularly intense near the lakeswhere breeding usually occurs, females adopted this tactic more frequently.
According to the study, approximately 86% of females persecuted by males dropped to the groundand of these, 77.7% managed to deceive the males by simulating their own death. This habit may have evolved as a response to sexual conflict, in which each sex develops strategies to maximize its own survival and reproductive success.
Khelifa suggests that females expanded the use of an existing anti-predatory function, feigning death to avoid predators, to also apply it to escape harassment by males. Faking death, although risky, appears to be an effective strategy for increase female survival and ensure a greater number of descendants.
This behavior allows them to avoid unwanted mating, reducing stress and the danger of being intercepted by males. Khelifa’s study is particularly significant as it documented one of the few known cases of “simulated sexual death,” a rare phenomenon in nature that has so far only been observed in a few arthropod species.
