Eyases are fed regularly by both parents, who pluck the feathers from the prey at a nearby plucking perch before taking the food to the nest. When the nestlings begin to fly, the parents fly by with prey in their talons and the young attempt to snatch it from them in midair as they pass. After several weeks of such instruction, the young begin to catch their own prey. The juvenile plumage is worn for a year with only slight changes due to wear and fading. Adults moult and replace the wing feathers, one at a time, during the summer.
Sexual maturity is reached at about two years of age.
Individuals have lived 18 or 20 years, but the average lifespan is probably much shorter. Conservation Peregrine Falcon populations were long noted for their stability. In Great Britain, for example, where a host of birdwatchers and falconers studied them, the breeding population of some 600 pairs changed little from Elizabethan days until the 1940s. During the war, peregrines were eliminated in some areas to protect homing pigeons. Although these populations recovered after the war, from about 1945 onward many once-vigorous peregrine populations suffered widespread, unprecedented declines, particularly in Europe and North America.