Birds beat helicopters in hover test
When it comes to flight, nature just has the edge on human engineers, say scientists.
A study has compared hummingbirds with some of the world's most advanced micro-helicopters and drones.
Researchers found that - in terms of the power they require to lift their weight - the best hummingbird was over 20% more efficient than the helicopter.
The average hummingbird, however, was the same as the helicopter, showing "how far flight engineering has come".
The findings are published in the Royal Society journal Interface.