There probably have been more arguments over the maximum speeds of birds than any other creatures. Estimated speeds for some species rate higher than 200 miles per hour, but most authorities believe some of these records, which were established several years ago, are a bit exaggerated. Many disagreements are based on the fact that the speed of a bird in flight often is measured as ground speed. This ground speed is determined by measuring the time required to fly from one fixed point on the ground to another. Since no consideration is given to the wind conditions in such a measurement, the results can be misleading. A bird flying at an airspeed of 25 MPH with a 35-MPH tail wind will appear to be flying at a ground speed of 60 MPH. If no wind were present, the bird would cover the same distance at only 25 MPH, and flying against a head wind would further reduce the speed. Measurements made with airplanes and radar devices have established flight speeds at lower, but possibly more accurate levels.
One of the slowest recorded speeds for a bird in flight is the 5 MPH credited to the woodcock. Fastest speeds are recorded for the swifts, falcons, and homing pigeons, depending upon which statistics are accepted. Two species of swifts, timed over a measured course of two miles in India, covered the distance in thirty-six to forty-two seconds. This places their speeds at 171 to 200 MPH. Since no data are recorded concerning the wind speed or direction at the time of the flight, their true airspeed could have been less. It is reported that on another occasion a flock of swifts overtook and circled a small plane traveling at 68 MPH. It is estimated that these birds were flying at 100 MPH.
Other authorities consider the homing pigeon to be the fastest bird because it can maintain a high rate of speed for long distances. It has been accurately measured at a speed of 94.3 MPH. One homing pigeon averaged 73 MPH over a distance of 182 miles, and several have flown over 90 MPH for distances of at least 80 miles.
The peregrine falcon, which preys on other birds, flies at speeds of 65 to 70 MPH, but it has been clocked at diving speeds of 170 to 180 MPH. Most ducks and geese can fly at a speed ranging from 60 to 70 MPH; however, their usual flying speed is much slower. At its 40-MPH cruising speed, the mallard out flies the teal, which cruises along at 32 MPH. But if pressed, both birds can accelerate to around 60 MPH.
Probably the most amazing speed, because of the bird’s small size, is that recorded for the hummingbird. With wingbeats approaching 200 per second, the ruby-throated hummingbird can dart from flower to flower at speeds up to 60 MPH.
http://www.tpwd.state.tx.us/publica..._naturalist/animals/animal_speeds/index.phtml
