The name Kestrel applies several raptors in the genus Falco, the falcons. The American Kestrel, Falco spaverius, is known as a Sparrow Hawk, and ther term Hawk is used widely for many other falcons. It is noteworthy that the University of Iowa's Tigerhawk logo has facial markings that somewhat resemble those of the kestrel. Among the raptors, kestrels are distinguished by being small and nimble, with the ability to hover while watching for prey and then diving for a capture.
The kestrel image in the header is derived from American_Kestrel_RWD1.jpg, which Dick Daniels made and placed in the Wikimedia Commons under the CC BY-SA 3.0 license. Therefore, that license also applies to this image.