Rufous Owl (Ninox rufa)

Scientific classification :

Kingdom : Animalia

Phylum : Chordata

Class : Aves

Order : Strigiformes

Family : Strigidae

Genus : Ninox

Species : N. rufa

Description: A large, rufous-coloured Owl of tropical rainforest. The forehead, crown, nape, back and upper wings are dark rufous, finely barred light brown. The upper tail is similar but with broader bars. The facial disc is indistinct and blackish brown. The throat, breast, and belly are rich rufous, finely and closely barred cream, the bars becoming broader and fewer from the throat backwards. Under the wings and tail is light brown, broadly barred cream. Rufous Owls have a long tail and feathered legs with pale yellow or creamy toes and black talons. Iris is yellow and the bill is pale horn with short black bristles at the base. The male always larger than the female and tends to have a broader, flatter head. Newly fledged young are much smaller than the parents and still part downy. Young adults tend to be more broadly barred than older birds with dark sepia rather than rufous colouring.

Size:

Length 46-57cm (18-22.5");   Wingspan 100-120cm (39.5-47")

Weight;  Female 700-1050g (24.75-37oz);    Male 1050-1300g (37-46oz)

Habits: A shy and elusive bird. Generally nocturnal. Will defend the nest very aggressively.

Voice: Rufous Owls are the least vocal Australian Ninox and call very little outside the breeding season. Pairs at roost may converse very softly. The commonest call is a deep, double hoot, similar in pitch and tempo to the Powerful Owl but more nasal, less ringing and with far less carrying power. A second note may be at same or a slightly higher pitch than the first. Female's calls are always slightly higher. Occasionally a single hoot may be used. The female has sheep-like bleating call similar to the Powerful Owl used when the male returns to the nest with food.

Hunting & Food: The Rufous Owl is an extremely versatile and powerful hunter taking a variety of prey from beetles to large birds and flying foxes. Prey recorded include Brush-turkey, Scrubfowl, Papuan Frogmouth, Blue-winged Kookaburra, White Cockatoo, flying fox, Sugar Glider, beetles, phasmids, several species of heron, ducks, parrots and, remarkably, crayfish. Prey have been seen to be taken from perches (Scrubfowl), by snatching from foliage in flight (phasmids), in aerial chases (flying fox) and by hawking like a giant flycatcher (beetles). The crayfish were presumably taken when stranded by falling floodwater.

Breeding: Like most Ninox, the Rufous Owl has a regular breeding season with egg laying varying from June in the Northern Territory to September in north-east Queensland. Individual females appear to lay at very much the same date each year. The presence of the previous seasons young may sometimes inhibit nesting for that season. As nesting approaches, both birds roost close together, often on the same branch. After dark, the male calls with a double hoot and the female may fly to him with excited bleating trills. Pairs perch side by side and the male preens the nape of the female's neck while she picks at his toes with her bill. Both sexes may be fiercely aggressive to humans in defence of the nest, which is a large hollow in the trunk or a main limb of a big tree, usually living but sometimes dead. Most nests are high, at about 30 metres (98 feet), but occasionally low at down to less than 3metres (10 feet). The male cleans out the hollow and female only enters immediately before laying 2 (or occasionally 1) eggs. There are 3 days in between laying the dull white, almost spherical eggs. They are 49-54mm (2") by 44-48mm (1.9"). Incubation is 37 days and the Young have a first and second whitish down. Fledging is about 50 days while still partly downy. The young remain dependent on adults for several months and this period may extend into the next breeding season.

Habitat: Rainforests, monsoon forest; wet, forested gullies, and adjoining woodland. Roosts by day in leafy trees.

Distribution: Arnhem Land and northern Kimberleys, eastern Cape York Peninsula, and the Mackay district of eastern Queensland. Rufous Owls are also found in New Guinea and the Aru Islands.

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Eurasian Eagle Owl (Bubo bubo)

Kingdom : Animalia

Phylum : Chordata

Class : Aves

Order : Strigiformes

Family : Strigidae

Genus : Bubo

Species : B. bubo

The upperparts are brown-black and tawny-buff, showing as dense freckling on the forehead and crown, stripes on the nape, sides and back of the neck, and dark splotches on the pale ground colour of the back, mantle and scapulars. A narrow buff band, freckled with brown buff, runs up from the base of the bill, above the inner part of the eye and along the inner edge of the black-brown, "ear-tufts".

The rump and upper tail-coverts are delicately patterned with dark vermiculations and fine wavy barring. The facial disc is tawny-buff, speckled with black-brown, so densely on the outer edge of the disc as to form a "frame" around the face. Chin and throat are white continuing down the centre of the upper breast

The whole of the underparts except for chin, throat and centre of upper breast is covered with fine dark wavy barring, on a tawny-buff ground colour. Legs and feet are likewise marked on a buff ground colour but more faintly.

The tail is tawny-buff, mottled dark grey-brown with about six black-brown bars.

Bill and claws are black, the iris is orange (yellow in some subspecies).

Size: Length: 58-71cm (22.8-28")

Weight: Female 2280-4200g (80.4-158oz) Male 1620-3000g (57.1-105.8oz)

Average Wing Length (one wing only): Female 47.8cm (18.8")  Male 44.8cm (17.6")

Habits: Active mainly at dusk to dawn. Flight is noiseless, whith soft wingbeats interrupted by gliding when flying over long distance. Will sometimes soar.

Voice: A deep, monotonous "oohu-oohu-oohu". The female's call is slightly higher than the male's. When threatened, they may bark and growl.

Hunting & Food: Eagle Owls have various hunting techniques, and will take prey on the ground or in full flight. They may hunt in forests, but prefer open spaces. Eagle Owls will eat almost anything the moves - from beetles to roe deer fawns. The major part of their diet consists of mammals (Voles, rats, mice, foxes, hares etc...), but birds of all kinds are also taken, including crows, ducks, grouse, seabirds, and even other birds of prey (including other owls). Other prey taken include snakes, lizards, frogs, fish, and crabs.

The most common type of prey depends largely on relative availability, but are usually voles and rats. In some coastal areas, they have been known to feed mainly on ducks and seabirds.

Pellets are somewhat compressed, irregularly cylindrical or conical shaped, averaging about 75 x 32 mm (3 x 1.25").

Breeding: The Male and Female duet during courtship, the Male advertising potential breeding sites by scratching a shallow depression at the site and emitting staccato notes and clucking sounds. Favoured nest sites are sheltered cliff ledges, crevices between rocks and cave entrances in cliffs. They will also use abandoned nests of other large birds. If no such sites are available, they may nest on the ground between rocks, under fallen trunks, under a bush, or even at the base of a tree trunk. No nesting material is added. Often several potential depressions are offered to the female, who selects one; this is quite often used again in subsequent years. Very often pairs for life. They are territorial, but territories of neighbouring pairs may partly overlap.

Laying generally begins in late winter, sometimes later. One clutch per year of 1-4 white eggs are laid, measuring 56-73mm x 44.2- 53mm (2.2- 2.9" x 1.7- 2.1") and weighing 75- 80g (2.6- 2.8oz). They are normally laid at 3 days intervals and are incubated by the female alone, starting from the first egg, for 31-36 days. During this time, she is fed at the nest by her mate.

Once hatched, the young are brooded for about 2 weeks; the female stays with them at the nest for 4-5 weeks. For the first 2-3 weeks the male brings food to the nest or deposits it nearby, and the female feeds small pieces the young. At 3 weeks the chicks start to feed themselves and begin to swallow smaller items whole. At 5 weeks the young walk around the nesting area, and at 52 days are able to fly a few metres. They may leave ground nests as early as 22-25 days old, while elevated nests  are left at an age of 5-7 weeks.

Fledged young are cared for by both parents for about 20-24 weeks. They become independent between September and November in Europe, and leave the parents' territory (or are driven out by them). At this time the male begins to sing again and inspect potential future nesting sites.

Young reach maturity in the following year, but normally breed when 2-3 years old.

Mortality:  Eurasian Eagle Owls may live more than 60 years in captivity. In the wild, about 20 years may be the maximum. They have no real natural enemies; electrocution, collision with traffic, and shooting are the main causes of death.

Habitat: Eagle Owls occupy a variety of habitats, from coniferous forests to warm deserts. Rocky landscapes are often favoured. Adequate food supply and nesting sites seem to be the most important prerequisites.

Distribution: North Africa, Europe, Asia, Middle East.

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Greater Sooty Owl (Tyto tenebricosa)

Kingdom : Animalia

Phylum : Chordata

Class : Aves

Order : Strigiformes

Family : Tytonidae

Genus : Tyto

Species : T. tenebricosa

Known also as Black Owls or Dusky Barn Owls, these birds are rarely seen or heard. A medium large, sooty black Owl with very large, dark eyes set in a round facial disc. The upperparts are sooty black, finely spotted white on the head with larger but sparser white spots on the wings. The Facial disc is large, round and sooty black through to dark grey or silver and is heavily edged black. The underparts vary from sooty black to dark grey, (never as dark as the upperparts) finely spotted with white. The Belly is always paler than the breast. The tail is very short, the legs feathered and eyes very large with a black iris. A Sooty Owl's Bill is horn coloured and feathered almost to the tip. Toes are dark grey and the large talons black. Sexes are similar in plumage and Females are usually slightly larger than males. They are distinguished from lesser Sooty Owls by much larger size and darker plumage, sparser white spots on upperparts and darker underparts which have white spots on a dark background where the lesser Sooty Owl has dark chevrons on a pale background.

Size: Female - Length 44-51 cm (17-20") Weight 750-1000g (26.5-35 oz) 

Male - Length 37-43 cm (14.5-17") Weight 500-700g (17.5-24.5 oz)

Habits: Strictly Nocturnal. Hides during the daytime in crevices, hollow tree trunks, dense foliage of tall trees, and sometimes caves.

Voice: The characteristic call is a piercing downscale shriek, lasting for upwards of two seconds. It has been likened to the sound of a falling bomb without the final explosion and the call is now widely known as the 'bomb whistle'. There are also various other calls associated with breeding and nesting.

Hunting & Food: The Sooty Owls is a powerful hunter and takes some remarkably big prey, a high proportion being arboreal. This contrasts not only with the lesser Sooty but with all other Tyto Owls, which take most of their prey on the ground. The huge eyes of both sooty Owls compared with other Tyto Owls suggests a greater reliance on vision. Sugar Gliders and Ringtail Possums make up a high proportion of the prey but a wide variety of other mammals have been recorded. There are no records of hunting methods. The male does all the hunting during breeding and usually brings one large prey item per night.

Breeding: The season is variable, with most eggs laid from January through to June but there are some records of laying in spring (August-September). Males often become more noisy at the start of the season, giving frequent 'bomb whistles'. The male feeds the female in the hollow, engaging her with soft, high-pitched trilling before passing over the prey. The nest is usually in a large hollow in a living tree at any height from 10 to 50 metres (33-164 feet). There are a few records of nesting in caves. Females occupy the hollow for many weeks before laying, flying out only briefly during night. A female in a cave nest site rarely leaves at all. 1 or 2 dull white eggs are laid, measuring 44-52mm (1.7-2") by 36-41mm (1.4-1.6"). Incubation is around 42 days. The young are covered in sooty grey down and are fledged in about 3 months. The newly fledged Sooty Owl is dependent on its parents for up to a month.

Habitat: Deep moist gullies in eucalypt forest, usually with big, old, smooth-barked gums and an understorey of tree ferns and Lilly Pilly. They may move into drier forest to hunt but they need the primary habitat for roosting and breeding. They are Territorial and sedentary throughout the year.

Distribution: Coastal and mountain regions of south-eastern Australia from the Dandenong Ranges near Melbourne to the Conendale Range north of Brisbane. Reportedly present on Flinders Island in the Bass Strait. They are also found in the Montane rainforests of New Guinea. 

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