Motion Camouflage
Dragonflies have a unique way of camouflaging themselves, enabling them to sneak
up on their prey in a way that makes them seem stationary even though they
are in fact moving closer. This trick, known as motion camouflage, was initially
discovered during observations of the mating tactics of male hoverflies tracking
females. Upon spotting a female, the male hoverfly appeared to shadow her,
maintaining a distance until she landed, at which point the male would move in swiftly
and mate with her.
As shown in a study done by Dr. Aikiko Mizutani of the Australian National University
in Canberra, the dragonfly achieves this by adjusting its position in order to always
occupy the same spot in its prey's retina. This makes it look stationary while it
is actually moving and fooling its prey. This technique requires precise flight
control and positional sensing. It has long been suspected that male dragonflies
and other flying insects employ this behavior during aerial combats.
Dr. Mizutani and his team used two video cameras to track dragonflies and worked
out 15 three-dimensional flight trajectories of interactions between dragonflies.
Out of 15, six showed clear cut evidence of active motion camouflage.
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