The peregrine falcon belongs to the genus "Falco," which is characterized by long pointed wings. In fact the word Falco is derived from "falx," the Latin word for sickle, in reference to the distinct sickle-shaped silhouette of the peregrine falcon’s extended wings in flight. Also unique to this species is the notched beak that is used to kill prey by severing the spinal column at the neck. The peregrine falcon is a crow-sized bird, weighing just over two pounds with a wing span of approximately 3 feet. An adult peregrine has a dark grey back and crown, dark bars or streaks on a pale chest and abdomen, and heavy malar (cheek) stripes on the side of the face. Immature peregrines are buff colored in front and have dark brown backs; adults are white or buff in front and bluish-gray on their backs. Females and males are identical in appearance, however, the female can be a third larger than the male.

Citations:

• Goodrich, L.J., and J.P. Smith. 2008. Raptor migration in North America. Pp. 37-149 in K.L. Bildstein, J.P. Smith, E. Ruelas Inzunza, and R.R. Veit (eds.), State of North America's birds of prey Nuttall Ornithological Club, Cambridge, MA, and American Ornithologists' Union, Washington, D.C
• White, Clayton M., Nancy J. Clum, Tom J. Cade and W. Grainger Hunt. 2002. Peregrine Falcon (Falco peregrinus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/660
• Wheeler, B.K., C.M. White and J.M. Economidy. 2003. Raptors of Western North America: The Wheeler Guide