The dramatic courtship dive of a small hummingbird has been found to be the quickest aerial manoeuvre in the natural world for an animal compared to its size. It even outpaces the movements of a jet fighter and the Space Shuttle on re-entry into the Earth's atmosphere.
Anna's hummingbird lives
in the American southwest and the courtship display of the male is renowned for its death-defying dive that ends abruptly with a dramatic upturn with outstretched wings and tail feathers that stop the bird from crashing into the ground.
Scientists calculated that the 80km/h speed of the hummingbird at the fastest point in its descent is equivalent to it moving 383 times its body length each second.
The G-force as it turns out of its dive is nearly nine times the force of gravity - the same as the maximum G-forces experienced by fighter pilots.
But Christopher Clark, of the University of California, Berkeley, estimates the G-forces created as the bird comes out of its dive would make many trained fighter pilots black out.
"During their courtship dive, male Anna's hummingbirds reach speeds and accelerations that exceed the previous performance records for vertebrates undergoing a voluntarily aerial manoeuvre," said Dr Clark.
"After powering the initial stage of the dive by flapping, males folded their wings by their sides, at which point they reached an average maximum velocity of 383 body lengths per second. This is the highest known length-specific velocity attained by any vertebrate."
Aerial diving is seen in the courtship displays of many other birds, such as nighthawks and snipes, and it is a common feature of many bird species that attack their prey from the air, such as kingfishers, seabirds and falcons. But Dr Clark said none came close to matching the speed and acceleration of the hummingbird.
- INDEPENDENT
