A question from Monty Python and the Holy Grail, we can see what scientists have discovered about unladen swallows. Please subscribe to continue learning what makes life AWESOME: https://BioBush.tv/subscribe
The study referred to in this video is Flight kinematics of the barn swallow (Hirundo rustica) over a wide range of speeds in a windtunnel Kirsty J. Park , Mikael Rosén & Anders Hedenström https://doi.org/10.1242/jeb.204.15.2741
Summarized, the results of that study were that European Barn swallows flew between 4 and 14 m/s, and they would only fly at 15 m/s for 20 seconds or less. But one of the swallows wouldn't fly at 14 m/s, so for the average airspeed velocity of a swallow is 13 m/s, which is 29 mph or 47 kph.