 The hen incubates the eggs which hatch in about thirteen days.The young are fed by both parents and fledge when about eleven days old, but are not fully independent for another twelve days or so.BirdLife International estimates that there are between 11 and 20 million thrush nightingales in Europe and that, as Europe forms somewhere between 50% and 74% of the bird's global range, the total world population may be between 15 and 41 million individuals.