Despite of their tiny brains, dragonflies are very efficient at catching small insects. These hunters are, in fact, very adept at catching their prey. They're considered one of nature's most successful predators, having the ability to catch more than 95 percent of their targets.
Dragonflies are believed to catch their prey, which includes mosquitoes, flies, bees and wasps, by copying each of the prey's steering movements. Findings of a new study, however, revealed that dragonflies use their predictive skills to catch their elusive prey.
For the new study, which was published in the journal Nature on Dec. 10, Anthony Leonardo, from the Janelia Research Campus of the Howard Hughes Medical Institute, and colleagues used motion-capture techniques to track the independent eye and body movements of dragonflies with reflective markers placed on different parts of their body while they chase their prey.
The researchers found that when a dragonfly chases its prey, it is guided by the anticipated movement, and not just by the mere movements of its target. Researchers observed that the dragonfly predicts where its prey will be headed to next and then adjusts its trajectories to intercept its target.
"Predictive rotations of the dragonfly's head continuously track the prey's angular position," Leonardo and colleagues wrote. "The head-body angles established by prey tracking appear to guide systematic rotations of the dragonfly's body to align it with the prey's flight path."
By analyzing the videos of dragonflies chasing a fruit fly or an artificial prey made of beads, the researchers observed that instead of responding to their prey's movement, dragonflies remained on their original course most of the time, which indicate that these insects have already plotted their predictive path to intercept their target.
The researchers also observed that the dragonflies aligned themselves in a way that they would intercept their prey from below so as to reduce their odds of being detected.
Although predictive motion is common in birds, fish and mammals, the study marks the first time that this is observed in insects.
"Until now, this type of complex control, which incorporates both prediction and reaction, had been demonstrated only in vertebrates," Stacey Combes, from Harvard University's Department of Organismic and Evolutionary Biology, wrote in reference to the study. "However, Mischiati et al. show that dragonflies on the hunt perform internal calculations every bit as complex as those of a ballet dancer."
