New research revealed how the incredible hawkmoth spots flowers in the dark and hovers over them as they sway in wind.
A team of researchers used high-speed infrared cameras and 3-D-printed robotic flowers to determine how the hummingbird-sized moth tackles these sensory and flight control challenges while adjusting to changes in light conditions, the Georgia Institute of Technology reported. They found the insects can slow down their brains to improve their ability to function in the dark.
"There has been a lot of interest in understanding how animals deal with challenging sensing environments, especially when they are also doing difficult tasks like hovering in mid-air," said Simon Sponberg, an assistant professor in the School of Physics and School of Applied Physiology at the Georgia Institute of Technology. "This is also a very significant challenge for micro air vehicles."
Scientists already knew these moths, which seek out flower nectar in the dusk and dawn, us specialized eye structures to capture as much light as possible. This is the first concrete evidence that these moths slow down their brains to see better as well.
To make their findings, the researchers used robotic flowers that could be moved from side to side at controlled rates; the light conditions and frequencies at which the flowers moved could also be controlled. They looked at how well free-flying moths were able to keep their tongues in the flowers.
"We expected to see a trade-off with the moths doing significantly worse at tracking flowers in low light conditions," Sponberg said. "What we saw was that while the moths did slow down, that only made a difference if the flower was moving rapidly - faster than they actually move in nature."
The moths tracked robotic flowers that were moving at rates of about 20 oscillations per second, which is much faster that the two-hertz maximum that has been observed in nature. The moths' wings beat at a rate of about 25 strokes per second, so they had to adjust the direction of their movement with nearly every wing stroke.
"This is really an extreme behavior, though the moth makes it look simple and elegant," Sponberg said. "To maneuver like this is really quite challenging. It's an extreme behavior from both a sensory and motor control perspective."
These new findings could be used to improved sensors on human-engineered machines, and could even have broader applications in the field of artificial intelligence.
"If we want to have robots or machine vision systems that are working under this broad range of conditions, understanding how these moths function under these varying light conditions would be very useful," Sponberg said.
The findings were published in a recent edition of the journal Science.
