In Texas where owl houses are built, for example, egg-laying typically occurs around mid-to-late March. Like with spring's leafout period in our trees, the timing of such an event changes with a difference in latitude. After about 30 days of incubation, the eggs hatch. The nestlings spend the next 28 days or so in the nest before fledging (which could be mid-May or later). Nestlings are 20-22 days old when first observed in the owl house's entrance. Before that, they are too young and weak to make the climb. Once they fledge, they do not return to the nest cavity. Immature owls are paler and fuzzier than the adults and they have stubby ear tufts and noticeable horizontal barring across the breast (instead of the dark vertical breast streaks of the adult).