The world's fastest animal is the Peregrine Falcon (or Falco Peregrinus in Latin), which means "traveler hawk". It can reach speeds up to 321 km/h while hunting.

This hawk can be easily identified because of its long pointed wings and long tail. The male, having widths up to 1.38 m., has a gray back and big black mustache, while the female is surprisingly larger than the male This hawk has a unique method of flight since it can alternate rapid wing beats and long glides. As for weight, they can have the same weight as a raven.

They get their food from birds, bats and other mammals that they distinguish while they fly. Peregrine Falcons hunt from above, meaning that when they find their prey then they swoop down, reaching speeds up to 321 km/h. This is the maximum speed that could be calculated, but there are hypotheses indicating that they might reach up to 400 km/h in low altitude and 600 km/h high altitudes. This is feasible because of their amazing eyesight, even in low light. Descending at that speed, the unavoidable air pressure change could damage their lung tissue but this does not happen because of their sophisticated bony tubercles, which prevent them from getting such injury. These unique features made humans used peregrine falcons during World War II to intercept homing pigeons. Today, they are also used to keep birds off in several airports around the world.

When migrating, they fly very long distances, even 500 km a day. Interestingly, it is a bird that often returns to the same nesting sites. Different studies point out that some birds have returned to the same place in England since 1243.  Thanks to this ability to travel, the only places on Earth that Peregrine Falcons cannot be found are in Antarctica, New Zealand and Iceland. In conclusion, if we put an odometer to any of these falcons, they could reach around 25,000 km throughout its life.

This type of falcon can be found on mountains and cliffs, particularly in depressions on bare rocky edges. They can also be found in abandoned nests of other species. Their nesting process consists on laying 3 or 4 eggs between March and April, hatching 28 to 30 days later and leaving the nest after about 40 days, when the chicks start to fly. These chicks have an impressive growth, since they double their weight after 6 days of age. After 3 more weeks, they can even reach 10 times their size of birth. It is estimated that they can live up to 15 years and begin to reproduce at 2 years of age. Due to nest destruction and poisoned agricultural pesticides, the amount of this specie is decreasing at a really fast rate.

http://en.wikipedia.org/wiki/Peregrine_falcon

http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdguide/name/p/peregrine/index.aspx

http://www.defenders.org/peregrine-falcon/basic-facts

http://www.arkive.org/peregrine-falcon/falco-peregrinus/

http://animals.nationalgeographic.com/animals/birds/peregrine-falcon/