Abundance: Common. Breed throughout all states of Australia, Norfolk Island, and adjacent Nepean and Phillip Islands.
Habitat: Grasslands, farmlands, fields, meadows and woodlands. They characteristically quarter up and down likely-looking areas for their main quarry, voles and mice, but will sometimes scan the ground from a lookout post. May roost on ground, nest in farm buildings, amongst the rafters, or on specially constructed nesting platforms. Feed mainly at night, hunting in total darkness, but are occasionally seen at dusk.
Description: Slim; upright posture. Small black eyes. Rounded heart- shaped mask; brown border, white disc, dark tear marks. Upperparts soft grey, patchily washed golden-fawn and marked with fine black, white-tipped spots. Underparts white, sparsely dark-flecked. Long, unfeathered lower legs protrude just beyond tail in flight.
Size: Females 35cm. Males 34cm.
Voice: Rasping speech.
The Barn Owl thrives in Australia, where its nomadic habits allow it to take advantage of the periodic rodent plagues that are such a feature of Australian life. Historically the Long-Haired Rat (Ratty villosissimus), was the species most commonly involved. Then the early European settlers arrived with their grain crops. With them came the House Mouse (Mus- musculus), which multiplied so rapidly that it was soon the commonest plague rodent in Australia; a curse to wheat farmers but a boon to Barn Owls, which respond to the temporarily limitless supplies of food with prolific and continuous breeding.
Of course, rodent plagues do not last forever and, with the inevitable crash in numbers, the predators suddenly find themselves without food. It is the classic boom and bust cycle so beloved by economists but, for the Barn Owl, it usually means death. Many predators can turn to other food sources but the Barn Owl is a rodent specialist and is doomed without them. With food supplies failing, the Barn Owls disperse, often appearing along roads and in farm buildings, conspicuous in their starvation.
The classic experiments of Roger Payne at Harvard University (1961) have demonstrated the ability of the Barn Owl to hunt in total darkness.