The boobook owl, or Mopoke ( Ninox novaseelandiae) is the smallest and most common owl species in Australia. It's found all across the continent, wherever there are trees suitable for nesting and roosting, and also ranges into New Zealand, New Guinea, Norfolk Island and southern Indonesia. They can be heard surprisingly often in Sydney at night. Their call is a distinctive two syllable boo-book or mo-poke, giving the species its common names, and it also has a trilling, whistling call.
They're quite small for an owl, at about 30cm long including a broad tail. Their body is dark brown mottled with white and grey, with dark bown wing and tail feathers trimmed with white. Their face is very broad, and this is exaggerated by a marking across the forehead that looks exactly like a pair of bristly white old-man eyebrows. The rest of the face is dark, fading slightly towards the eyes. The eyes themselves are lined with black, with huge, round, vivid yellow iris and round black pupil. The beak is shiny black, and the legs are covered in soft white fluff.
They roost in tall trees during the day, and are very reluctant to move if discovered. Instead they sit upright, feathers pulled close to the body, and turn side on to the intruder, appearing very long and slender. They are often mobbed by flocks of small birds, and the best way to see one during daylight hours is to listen for the alarm calls of a group of small honeyeaters.
They get revenge at night, however. Small birds are the major diet of Boobook owls, although the house mouse mus musculus is another favoured item of diet. They also eat whatever remaining small native hopping marsupials are around, as well as a lot of invertebrates. For a month or so every year the eastern seaboard is infested with Bogong moths, and the owls take full advantage of this convenient fact. Which is a good thing, as it means less moths in my bathroom.