Young Barn Owl (Tyto alba). Barn Owl chicks are relatively slow to develop. On average they take 8 weeks to fledge (develop full flight feathers) and remain dependent on their parents for a further 3 to 5 weeks. Barn owls prefer sheltered nesting sites because their lightly oiled plumage is vulnerable to soaking. They prey on small animals, mainly rodents. They hunt at night and can find their prey by sound alone. Barn owls are geographically widespread, being found on 5 continents.