The Airspeed of an Unladen Swallow in Flight

"WHAT ... is the airspeed of a laden swallow in flight?"

One of the classic questions of science popular culture Monty Python fans, but before weighing down a 20 gram bird with the fruit of a Cocos nucifera, someone really ought to look into how they fly normally.

And of course, someone has.

"In order to maintain airspeed velocity, a swallow needs to beat its wings forty-three times every second, right?"

Actually, wrong. By comparing the European Swallow with bird species of similar body mass, we can estimate that the swallow beats its wings 18 times a second with an amplitude of 18 cm:

Species	Body mass	Frequency	Amplitude
Zebra Finch	13 g	27 Hz	11 cm
European Swallow	20 g	≈ 18 Hz?	≈ 18 cm?
Downy Woodpecker	27 g	14 Hz	29 cm
Budgerigar	34 g	14 Hz	15 cm

Check out the full article at Style.org.


Or ... you could go with the original research!



Now that I think about it, I must have posted this once before. But what the heck, it's worth repeating. :-)