List of birds by flight speed
This is a list of the fastest flying birds in the world. A bird's velocity is necessarily variable; a hunting bird will reach much greater speeds while diving to catch prey than when gliding. The bird with the greatest airspeed velocity is the Peregrine falcon, able to exceed 321.8 km/h (200 mph) in its hunting dives. The greatest self-powered horizontal speed is achieved by Homing Racing Pigeons. They can fly 1100 km (700 miles) in a single day, and they have been recorded flying at 177 km/h (110 miles per hour), making them the birds with the fastest speed ever recorded on a self-powered flight, and the fastest endurance flight.
Mammal
Bats are the only mammals that can truly fly. They fly through the air at a constant speed by moving their wings up and down (usually with some fore-aft movement as well). Because the animal is in motion, there is some airflow relative to its body which, combined with the velocity of the wings, generates a faster airflow moving over the wing. This generates a lift force vector pointing forwards and upwards, and a drag force vector pointing rearwards and upwards. The upwards components of these counteract gravity, keeping the body in the air, while the forward component provides thrust to counteract both the drag from the wing and from the body as a whole.