Immature peregrines have brown backs with heavy, dark streaks below. They get their adult plumage in their second year, although most do not reproduce until they're 3 years old. Historically, the peregrine falcon ranged throughout North America and much of the world. In the eastern United States, they nested from the Great Lakes and eastern Maine south to Georgia and Alabama. Numbers were never large because each pair requires a large feeding territory centered around a suitable nesting site.
Peregrines usually nest on high, remote, cliff ledges.
In recent years, they have substituted buildings, bridges and other artificial structures. Mating involves an intricate and prescribed ritual. The smaller male arrives first and courts females by performing aerial displays consisting of loops, dives and rolls. The pair may return to the same cliff in subsequent years, though they do not stay together after nesting. In the Northeast, nesting begins in late March.