I know that Perigrine Falcons are consider the fastest flying bird - with some pigeon coming very close. Max speed in straight flight lays around 120 km/hr - P. Falcon have in Denmark at Moens Klint been logged at 264 km/hr in hunting dive.
I can remember a pair of Rock Pigeons in South Africa flying alongside the road while driving at 60mph. They were weaving in and out of the tops of Blue Gum trees all the while keeping level with the car.
I figured out years ago that Birds and Insects Don't move wings up, then down, like an engine piston.
They use Springs ;-)
That is their whole wing system and flight mussels form a spring system which will oscillate on its own. So when the bird pulls its wings down, they will automatically spring back up to the high position. So all the bird has to do is keep this oscillation motion going. So much less energy is required to maintain flight. You can see that in the figures they gave, each bird species has its own natural frequency, but that will be modified by age, wing size etc.
They row through the air. Figure 8 motion. Even the back stroke creates lift and forward motion.
Makes our jetfighters look a bit silly for efficiency, eh?
Yes they do "Row" through the air.
I think it is more of a figure of "0" that they move their wings round in, a bit like swimmers doing the "Butterfly" stroke.
That figure of "0" action, together with changing the angle of attack of their wings, makes for very efficient use of energy.
I even designed a man powered craft round that principal, but never had the time etc. to try to build it.
Most birds fly with their tail flat, twisting for manoeuvring.
But the black birds here, fold their tail feathers up to form a vertical Fin, only flattening the tail for landing.
The Peregrine Falcon has traditionally had the crown for speed, but the Lanner Falcon indigenous to Africa is equally as fast, if not maybe more so. It is jut not as well known a species of falcon. The falcons probably are the fastest of the birds.
I was once on the side of a mountain when a Golden Eagle came past in an almost vertical dive. I just saw a brown flash and the wind whine in it's feathers extremely loud. Fortunately I had binoculars and could identify it when it pulled out of the dive.