Vancouver – Roslyn Dakin, a post-doctoral fellow at the University of British Columbia, have found that hummingbirds have very exceptional eyesight that allows them to avoid collisions at high speed.
For years, hummingbirds have baffled scientists with their ability to fly 50 km/h, make 100 kilometers per hour dives and steer a correct course at high speed, while avoiding collisions with the ground and surrounding objects. But now, according to a study was published Monday in the Proceedings of the National Academy of Sciences, we know the causes.
Roslyn Dakin, a biologist and post-doctoral fellow at the University of British Columbia directed the experiment, where he and his team used a long chamber to manipulate the little birds’ visual environment.
What they found was astonishing: The hummingbird eyesight can monitor at the same time, the relative position, expansion and vertical size of the objects they found in their path, which requires a very complicated and different image processing ability.
They figure out whether the obstacles get larger (which means they are getting closer) or smaller (they are moving away), something that has never been recording in another flying animal. According to Dakin, this is different from the way insects avoid a collision, for example, honey bees and flies figure this by processing how quickly the obstacles pass through their field of vision.
Use the mental image of somebody driving: While on the car, telephones poles along the road apparently move more quickly than buildings that are very far away from the road. This is known as “pattern velocity” and it’s very imperfect, given how regularly insects crash into things.
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How the scientists managed to figure this out?
Firstly, they built a 5.5 meter-long flight tunnel that took months to make and was equipped with eight cameras to track and record the hummingbirds’ reactions to perceived obstacles.
According to co-author and zoology professor, Douglas Altshuler “we took advantage of hummingbirds’ attraction to sugar water to set up a perch on one side of the tunnel and a feeder on the other, and they flew back and forth all day […] this allowed us to test many different visual stimuli.”
Since the hummingbirds have to drink nectar every ten minutes, it was very easy to make them fly thousands of times per day,
Dakin’s colleagues are now focusing on the stimulus that happens in the hummingbird brain when the tiny bird is analyzing the size of the objects around it. The current hypothesis is that their brains are more neurologically complex.
This discovery could help engineers built better drones since it could contribute to creating smarter navigational algorithms for better flying. Scientists are already using flying insects that save energy in the air; but as we stated before, their sense of direction and avoidance is not the best. This is where hummingbirds enter to help saving energy drones navigate with fewer crashes.
Sources: ABC2 News