When was the last time you saw a hummingbird crash?
These little birds can fly at over 30 miles per hour and stop in an instant. So the question is, how does the way they see help them avoid high-speed collisions?
Researchers in Canada already knew coming into their study on this topic that bees evaluate distance based on how long something takes to pass their visual field.
It's like when you're on a road trip, as telephone poles and trees come in and out of view.
But hummingbirds didn't adjust their flights when the researchers simulated this kind of information in a tunnel they created.
Instead, researchers found hummingbirds rely on the size of an object to know if they're getting close. When the researchers made the patterns on one side of the tunnel bigger than the other, the birds flew closer to the smaller patterns.
The trick is these patterns were a series of horizontal lines, meaning the birds judge an object's location and size in the vertical axis.
The researchers noted hummingbirds may not fully grasp the size of objects around them, but monitoring how the sizes of things change helps them avoid high-speed collisions.
This video includes clips and images from the University of British Columbia. Music provided courtesy of APM Music.