The rufous owl is a large bird, often growing 46–57 centimetres (18–22 in) in length, with a wingspan of 100 to 120 centimetres (39 to 47 in). Females typically weigh 700–1,050 g (25–37 oz), while the males typically weigh 1,050–1,300 g (37–46 oz). Both sexes have relatively small heads compared to their body and tail, but the head of the male is flatter and broader than that of the female. Juveniles are much smaller, usually 49–54 mm (1.9–2.1 in) long at birth, and are covered in downy white pelage . The forehead, neck, back, and upper wings of the adults are usually a dark reddish-brown with light brown barring scattered throughout. The face is dark brown, and the neck, breast and underparts are rufous with thin cream bars. The underside of the wings are light brown with thick cream bars. The hooked bill is light grey and is surrounded by black bristles at its base. It has golden-yellow eyes.
Ninox rufa has a wide geographic range. It is native to the Aru Islands , New Guinea and northern Australia, where it is found in Arnhem Land , the northern Kimberleys , the eastern Cape York Peninsula , and the Mackay District of eastern Queensland . It is the only exclusively tropical owl in Australia. The global population size of Ninox rufa has yet to be determined, but the species is considered uncommon to rare.
Rufous owls are characterised by having rather shy and elusive natures but are known to become aggressive if threatened. They are almost exclusively nocturnal birds and will remain in their nest or roost during the day. They are generally not very vocal, except during the breeding season. During this time, males and females will communicate to one another using calls of various pitches. The voice of the female is of a higher pitch than the male’s.
The rufous owl has a regular breeding season from June to September, depending on the warmth of its habitat. To initiate breeding, the male will utter a double call which will attract a female to him. As she flies toward him, the female will give excited trills in return. Eggs are typically laid in a nest located in the trunks or limbs of trees. Some nests are built as high as thirty meters above the ground in order to protect them from ground-dwelling predators. The male owl will select the nest and the female will lay one to two eggs inside. The eggs require 37 days of incubation. Once hatched, the young owls are dependent on their parents for many months, often until the following breeding season. The adult males and females will both aggressively defend their nests against predators and intruders while the young still reside inside.
The rufous owl is a skilled and powerful hunter, capable of capturing a wide variety of prey. Their diet is extremely diverse, ranging from birds and insects to small mammals such as flying foxes. Mammal prey sizes have been recorded from small rodents of 5 to 15 grams to larger arboreal marsupials such as the Northern brushtail possum (1100 to 2000 grams). Typically, the rufous owl will hunt the juveniles of these larger prey species. Mammals that the rufous owl has been documented to feed upon include the following: , , , , , , , , , , and others. They also take birds such as orange-footed scrubfowl and Eclectus parrot.
Seasonal changes in selection of prey have been determined from one study in Australia. For instance, when ground vegetation is more dense during the wet season, these owls appear to prey more often on other birds than ground-dwelling mammals. Selection of prey is also largely dependent upon the availability of species during the different seasons. In order to catch their prey, Rufous Owls have been observed to utilize several predation methods. They may take prey from perches, snatch from tree foliage while in flight, chase while in flight, or swoop from the air and catch their prey from the ground or water below.
Discover the Wild – Ruby the rufous owl
Join the Territory Wildlife Park staff for fun, educational talks as they bring the wild into your home. Discover the Wild is part of the Northern Territory Government’s Discover from Home series.