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Author Topic: How fast does a Hummingbird beat its wings?  (Read 15649 times)

thedoc

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How fast does a Hummingbird beat its wings?
« on: 23/07/2012 22:30:01 »
Hong Shee asked the Naked Scientists:
   
Hi Dr Chris,

My friends and I were watching TV one day and we came across a documentary on hummingbirds. The documentary says that some species of hummingbird can beat their wings over 1000 times per minute. After we had heard that, we debated, for hours, on whether the hummingbirds could actually beat its wings that many times per minute, or it is just an extrapolated figure - using the wing speed. Was there any study done on this? Is it possible for hummingbirds to hover for a full minute? Or is the beat per minute figure exaggerated?

I hope that you can help us settle our debate once and for all.

With great thanks,
Hong Shee

What do you think?
« Last Edit: 23/07/2012 22:30:01 by _system »

Don_1

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Re: How fast does a Hummingbird beat its wings?
« Reply #1 on: 24/07/2012 10:40:16 »
High speed cameras were used to determine the number of flaps per second and wind tunnels to establish lift.

The wingbeat rate of 1000 beats per minute in the documentary was a none too accurate average. Depending on species, Hummingbirds can beat their wings at between 12 - 80 times per second.

The largest, the Giant Hummingbird, has a wingbeat rate of around 12 - 15 beats per second.

The Rufus and Ruby Throat beat their wings around 50 times per second and a study revealed that 75% of the lift was from the down beat and 25% from the up beat.

The Amethyst Woodstar Hummingbird was once recorded beating its wings 80 times per second and it is believed that the Bee Hummingbird, the smallest of the species, may be capable of even greater numbers of beats per second.

This extraordinarily high beat rate would be reduced during flight and the term 'beat' is perhaps a little missleading when the bird is hovering, since the wings move in a more circular motion, giving the hummingbirds the ability to be the only bird which can fly backwards.

Just how long a hummingbird can keep up the higher rate of beats per second, I don't know, but to extrapolate the beats per second into beats per minute might be wrong, since it is unlikely that the bird would hover continuously for such a length of time. To do so would result in the Bee Hummingbird being extrapolated to something in the order of 5400 beats per minute. I think it clear that the bird could not sustain such an effort.

I think the documentary quoted the number of beats in terms of minutes for effect. As I have done above, to say '5400 per minute' has more impact than to say '90 beats per second', which the Bee Hummingbird is thought to be capable of.

RD

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Re: How fast does a Hummingbird beat its wings?
« Reply #2 on: 25/07/2012 05:01:42 »
High speed cameras were used to determine the number of flaps per second ...

or look at the waveform of the buzzing sound its wings make ...



[about 50Hz in this case].

 

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