Flight: Speed and distance
Flight has, however, permitted birds to be both the fastest moving animals and the animals that travel the most distance. The Carrier Pigeon (Columba livia; Columbidae) attains a maximum racing speed of 96 km/h, ducks can reach 145 km/h and the swift (Apus apus) 170 km/h in level flight. The swift may travel up to 900 km each day to collect aerial insects which is its only source of food, and this species even copulates in flight. The Peregrine Falcon (Falco peregrinus) during a dive can achieve speeds of 267-290 km/h, and has swept its wings back to reduce drag even further.
No other creatures can fly as fast or as far as birds. Many species of bird make long journeys. The White Stork (Ciconia ciconia; Ciconiidae) travels every autumn down to Africa and returns to Europe in the spring navigating with such accuracy that the same pair, year after year will occupy the same nest on the same roof top. However, the Arctic Tern (Sterna paradisea), holds the record for long-distance migration. The extremes of its Arcticnesting and Antarctic wintering ranges are 16 700 km apart. Since the routes taken are circuitous, these birds may fly 40 300 km each year. During the autumn, many birds gather in flocks and fly southward, returning the following spring. A lesser and opposite movement occurs in the Southern Hemisphere, where the seasons are reversed. Some other birds perform altitudinal migrations into mountainous regions for the summer and return to the lowlands to winter. In Africa young Starred Robins (Pogonocichla stellata; Turdidae) moves from the high interior forests to the warmer river valleys with the onset of autumn and winter.