For comparison, chickens incubate their eggs for 21 days and turkeys for 28 days. Males bring food to incubating females. This incubation strategy results in siblings occuring in stair-step ages. The first owlet may be 6 to 18 days older than its youngest nest mate. This age difference is visible in the varying size and plumage development of nestlings.
Young owls fledge when they are about eight weeks old.
Parent owls keep busy feeding themselves and their hungry owlets. Each adult consumes the equivalent of a large rat every night. Each owlet would eat up to a dozen mice per night if given the opportunity. With a normal nest containing six young, parent birds must capture up to 74 rodents nightly. To capture such a supply of food, adult owls may travel three miles.