The hawkmoth feeds by inserting a proboscis into a flower and drinking its nectar, a task that is complicated given lower light levels at dusk.
Now scientists have studied the visual abilities which make feeding time easier for the hawkmoth. A team of researchers spent months studying the hawkmoths in order to find out how the moths manage to eat, writes James Gorman for The New York Times.
Feeding time made easier by slower visual processing
The difficulties are summed up Georgia Tech scientist Simon Sponberg, who said that a hawkmoth has to hover “while they’re feeding from a flower with a proboscis that can be as long as their body while the flower is moving in the wind.”
In order to do so successfully, they need to be able to see the flower clearly in a situation with “light levels at which we’d have trouble seeing the hand in front of our face,” continued Dr. Sponberg.
Researchers say that the moths are capable of slowing their brains in order to receive more light, and see the flowers more clearly. Previous evidence had shown that visual processing could be slowed in hawkmoths, but this is the first time that its use has been proven during feeding in low light.
Tests could lead to innovation in robotics
A test involving robotic flowers and high-speed video allowed the scientists to monitor the moths behavior during feeding. Data showed that the moths struggled to keep track of fast-moving flowers, proving that their visual processing was slowed down. The phenomenon is also illustrated by the way that fast motion appears blurred in photographs taken at a slow shutter speed.
The moths suffered the biggest loss of ability to follow the movements of flowers which oscillated at faster than 1.7 times per second.The longer visual processing did not significantly affect their abilities at speeds of less than 1.7 times per second, and further research showed that the flowers which hawkmoths feed on most often oscillate at less than that speed.
Dr. Sponberg’s interest in the animals is driven by his desire to engineer robots which capture the “grace and agility” of animals. The study of the hawkmoth’s visual capabilities could also help to improve the performance of light sensors in robots.