Rassin Khelifa is a zoologist from the University of Zurich who published a study which studied odonates pretend to lose their life as a tactic to avoid mating and the rare instance of animals faking their own ends for this same purpose. Odonates is the order of insects that includes damselflies and dragonflies, and Khelifa had been collecting the eggs of odonates in the Swiss Alps in order to experiment how temperature affects larvae. However, he noticed something very unusual among female dragonflies of the species Aeshna juncea while there.
He wrote in a study published in the journal Ecology that he witnessed a dragonfly dive to the ground while being pursued by another dragonfly. The individual that crashed down was a female, and she was lying motionless and upside down on the ground.
He explains that upside down is an atypical posture for a dragonfly, so the male hovered above the female for a few seconds and left. He expected the female to be unconscious after her crash landing, but as he approached, she quickly flew away. So, the question arose: Did she trick that male? Did she crash and pretended to be lifeless to avoid male harassment?
There are few instances of animals faking their own end, and four of them are known to science. It includes two species of robber fly, the spider species Pisaura mirabilis, and the European mantis.
He documented dozens of cases over the next few months where females would crash land and pretend to be unconscious while being pursued by a male.
According to his observations, females would arrive at the ponds where the males were waiting to mate. The male would then fly away, and the female would lay eggs on her own, without any protection, unlike many other dragonfly species.
Females would crash to the ground in 86% of the cases, and further observations showed that the more male competition there was, the more likely female dragonflies were to crash land. The ones that kept flying “were all intercepted by a male”, and of the 27 motionless females, 21 were successful in deceiving the male.