These small fliers are also the most sophisticated on earth. Hummingbirds have taught scientists a new mechanism that can help to improve navigation and build better drones.
Most insects such as honeybees use visual clues or pattern velocity to pass by objects. However, this does not prevent them from crashing into obstacles. Scientists found that birds tend to fly better, rarely crashing into anything. However, it was not clear how birds managed to do that.
To solve their mysteries, biologist Roslyn Dakin of the University of British Columbia studied hummingbirds. "Hummingbirds are sugar fiends - they have to take a drink every ten to fifteen minutes," she told Gizmodo. "That means we can put a bird in a chamber and get him to fly back and forth hundreds of times over the course of a day."
Hence, Dakin and her team put a common Pacific hummingbird called Anna's hummingbird into a 5.5m-long tunnel with a perch at one end and a feeder in the other. They projected "still or moving patterns" of different sizes and orientations across the walls. They recorded and analyzed thousands of trips to and from the feeder.
The experts found that hummingbirds did not just steer away from walls with speedy patterns, which showed that they were not relying on simple pattern velocity cues. The rate of change of pattern size was more important.
"A tree branch 30cm away will expand more quickly than a tree branch 3m away if you approach both at the same rate. It appears that clever hummingbirds use slight differences in this expansion rate to determine when they're getting too close to an object, and to make course corrections accordingly," explain scientists.
This is the reason why hummingbirds are such good fliers. Dakin's team is studying the effect of steering in the hummingbirds brain.
"We want to pursue the idea that this could be more neurologically complex," Dakin said. "Hummingbirds are capable of such remarkable speed changes - Anna's hummingbirds do courtship displays where the males fly at up to 90 kilometers per hour, and they're able to just stop on a dime."
Hence, the research explores how the navigational algorithms can be used for aerial robots. The ideas from the flying insects can help experts in future to create robots that will face fewer crashes.
