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.
Animal locomotion
Gravity is the primary obstacle to flight. Because it is impossible for any organism to have a density as low as that of air, flying animals must generate enough lift to ascend and remain airborne. One way to achieve this is with wings, which when moved through the air generate an upward lift force on the animal's body. Flying animals must be very light to achieve flight, the largest living flying animals being birds of around 20 kilograms. Other structural adaptations of flying animals include reduced and redistributed body weight, fusiform shape and powerful flight muscles; there may also be physiological adaptations. Active flight has independently evolved at least four times, in the insects, pterosaurs, birds, and bats. Insects were the first taxon to evolve flight, approximately 400 million years ago (mya), followed by pterosaurs approximately 220 mya, birds approximately 160 mya, then bats about 60 mya.