Eurasian Tawny Owl - Strix aluco
Calls - Strix aluco
[For help with terms used in the description, see parts of an owl. For general characteristics common to most owl species, see owl physiology.]
Description: There are two basic colour types of Tawny Owls,
one being rich chestnut-brown, the other having grays instead of deep browns. Intermediate
birds are variously tawny-buff, buff-brown or grayish-brown in coloration.
The upperparts of the brown birds are of a rich tawny or sometimes a more
tawny-chestnut hue, streaked, mottled and vermiculated with dark brown and blackish-brown,
and mottled with lighter brown or tawny-buff. Bands of buff or whitish-buff mottling run
back and outwards across the crown from the central upper edge of the facial disc.
Black-brown mottling adjacent to these bands usually highlights this pattern. The
shoulders are variably tipped and edged whitish, forming ragged pale 'braces'. The face is
either pale rufous-buff, or deep buff with a tinge of rufous. The semi-circles and narrow
ring surrounding the eyes are buff. The facial ruff is densely flecked and edged dark
brown, forming a very narrow, dark edge to the facial disc. The bill is pale olive-yellow
and the very large eyes have bluish-black irises. Underparts are whitish or buff. Wings
are barred tawny-buff or buff and blackish-brown with brown mottling on the buff areas.
Tail feathers are tawny to tawny-chestnut, with the outer feathers barred dark brown. All
tail feathers are tipped grayish-white or buffish. The underwing is creamy-buff with a
dingy brown wash and gray-brown bars across primaries and secondaries. There is a
rufous-yellow wash on the tips of the underwing-coverts which are lightly streaked dark
brown with broad black-brown tips to primary coverts forming a dark semi-circular mark
near the bend of the wing. Legs are feathered and white with some brownish speckling. The
claws are blackish with dirty white bases.
Gray-brown birds have the same basic pattern as brown birds, though all
the browns are replaced by a much grayer hue.
Size: Males: length: 41-43.5cm (16-17").
wing span: 91-95cm (35.8-37.4"). weight: 410-550g (14.5-19.4 oz).
Females: length: 435-460 mm (17-18"). wing span 94-105cm
(37-41.3"). weight: 410-800g (14.5-28.2 oz).
Habits: Generally nocturnal, but sometimes active during the day. Flight is agile around trees, with relatively quick wingbeats. They will also glide on extended wings over open spaces, and may also hover. A very vocal bird, particularly during Autumn, winter and early Spring on clear calm nights. Can be very aggressive in nest defense.
Voice: The normal 'song' - the
familiar hooting of the male has several functions: it is a territorial call, a courtship call,
and an announcing call used when bringing food to the female. It consists of a long drawn
out hooo, a pause, an abrupt and subdued ha, usually followed at once by a prolonged and resonant
final wavering phrase huhuhuhooo. Sometimes, the female makes a similar hooting sound to the mating
male, however, the female's hooting is less clearly phrased than the male's, the last
phrase having a more wailing quality, approximately wow-wow-hooo, sometimes described it as a grating, hoarse version of the
normal song.
The contact call kewick and its variants is the most frequent
utterance of the female, but it is also used by the male. In spring the female may answer
the male's hoot with kewick as a kind of duet. When the female gives this call from the
nest the male generally responds soon afterwards by bringing prey to her, loudly
announcing his arrival.
A similar call is also made by the parents as a contact call when bringing prey to the
fledged young. The young will answer with their
cheeping call. Many other calls have been
heard during courtship and in territorial disputes. Piercing coo-wik cries apparently express aggression.
Hunting & Food: Tawny Owls hunt almost entirely at night,
usually waiting quietly on a perch, watching and listening. After detecting a prey animal
moving in the grass, the Owl glides down or drops onto it and, at the moment of impact,
extends its wings to cover the victim, which is usually killed immediately by the powerful
feet and claws. Sometimes a blow from the beak at the base of the victim's skull is also
used. Hunting on the wing alternating with hunting from a perch has been recorded in
Sweden. Tawny Owls have been reported to beat their wings on bushes to startle birds into
flight. They also snatch birds, and occasionally bats, from their roosting perches.
Incubating birds, such as Blackbirds, Woodcocks and pigeons, have been picked off their
nests.
Prey taken include rabbits, moles, mice, shrews, voles, and other rodents. They also
eat earthworms, insects (beetles especially), birds, frogs, fish,
lizards, molluscs, and crustaceans.
Pellets normally range from 30-70mm (1.2-2.75") in length and 18-26mm (0.7-1")
in width, and are usually of a loose texture and gray when dry.
Breeding: Tawny Owls remain within their nesting territory all
the year round and pair-bonds last for life. They are generally monogamous but some males
are known to be polygynous.
The first territorial fights occur as early as October and November, the male determining
the territory, the female the nesting hole. The transition from autumn to winter is marked
by a final establishment of territories and pre-breeding behaviour. The female and male
tend more and more to roost together. Courtship feeding begins in the winter period
(December to February), becoming progressively centred on the future nest site. In
Europe the Tawny Owl usually begins breeding in mid-March.
During courtship the male perches near the female and sways from side to side, then up and
down, raising first one wing then the other and finally both together. His plumage is
puffed out, making him appear almost round, then tightly compressed. Meanwhile he grunts
softly, sometimes sidling a foot or so along the branch and back again. He may indulge in
wing-clapping and when pursuing the female will utter screeches, mewings, groans and
rattles. The female may puff out and quiver her feathers.
Tawny Owls will nest in a natural hole or a nest box in a tree, but occasionally nests
have been found on ledges of old buildings and in chimneys. They will also use the old
nest of a crow, Magpie, Sparrowhawk or Buzzard, and sometimes a squirrel's
drey. They will
also use a Raven or Buzzard nest on a cliff or simply a bare ledge. According to Donald
Watson, ground nests are quite common in Galloway, in south-west Scotland.
Tawny Owls lay from two to six eggs, but sometimes only one. The eggs are almost round and
pure white and are about 46.7 x 39mm (1.84 x 1.54"). Normally, they are laid at
intervals of 48 hours, and are incubated for 28-29 days by the female alone. When the
young have hatched, the male brings more food, either to the nest or to the female waiting
nearby. Once the chicks are 6-7 days old the female may leave the nest only to hunt,
otherwise remaining near the young. Fledging occurs after 28 to 37 days. Tawny Owls are
dependent on their parents for food up to three months after leaving the nest. As
the young owls gradually learn to fend for themselves they also establish territories.
Territory size depends on terrain and prey availability. Territories may range from 12 ha
(30 acres) in closed woodland, through 65-75 ha (162.5-187.5 acres) when living in
beechwood with little lesser vegetation, to 102 ha (255 acres) in Norway, where the prey
density is far less than in England or Belgium. The Tawny Owl defends its territory
vigorously against neighbours with 'song', with threatening behaviour or in flying
skirmishes. Predatory mammals, too, such as cats, foxes and dogs, are driven from the
vicinity of the nest. Occasionally a Tawny Owl female with nestlings may attack a human
approaching the nest, even in daylight, and may even draw blood with its talons. In
Britain at least two people are known to have lost an eye from attacks. (Eric Hosking, the
famous bird photographer, had this happen to him quite early in his career.)
Mortality: The Tawny Owl reaches sexual maturity within a
year and can, therefore, breed during the first year of its life. In central Europe, one
ringed Tawny Owl lived 18 years and 7 months and in Britain one caged Tawny Owl survived
27 years.
Many young Tawny Owls lose their lives when trying to secure a territory inside the
parental one - they must either starve or move out. The most common fatalities connected
with man are collisions with vehicles, trains or wires, and getting trapped in buildings.
Habitat: Tawny Owls usually breed in broadleaved woodland and forests and
open parklands although occasionally they inhabit coniferous forests. Though woodland is
their preferred habitat, they are adaptable and have even taken up residence in cities
such as London and Berlin where there are large wooded parks and gardens.
Distribution: The world distribution of Tawny Owls
extends throughout Europe and North Africa (Morocco, Tunisia and Algeria) eastwards to
Iran and western Siberia. The Asiatic range covers north-western India, the Himalayas,
southern China, Korea and Taiwan. In Europe the Tawny Owl is the commonest and most
widespread owl, being absent only in Ireland, the extreme north of Scotland, northern
Russia, northern Scandinavia, Iceland and some of the Mediterranean islands.
Distribution of the Eurasian Tawny Owl Strix aluco
Status: Generally common.
Original Description: Linnaeus, Carolis. 1758. Systema Naturae (Syst. Nat.) ed. 10: p 93.
Subspecies:
S. a. aluco,
S. a. biddulphi,
S. a. harmsi,
S. a. ma,
S. a. mauritanica,
S. a. nivicola,
S. a. sanctinicolai,
S. a. siberiae,
S. a. sylvatica,
S. a. willkonskii,
S. a. yamadae
References:
Page Information:
Page compiled by Deane P. Lewis. Page last updated 2012-08-13
OwlPages.com Owl Species ID: 130.050.000
External Links:
Observation d'une famille de chouettes hulottes - [French] Observations of a Tawny Owl family in France.
Tawny Owls - a very good resource on Tawny Owls, covering nesting and vocalisations among other things.
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Typical Male
