[order] STRIGIFORMES | [family] Strigidae | [latin] Strix aluco | [authority] Linnaeus, 1758 | [UK] Tawny Owl | [FR] Chouette hulotte | [DE] Waldkauz | [ES] Carabo Comun | [NL] Bosuil
Subspecies
Monotypic species
Genus
Members of the genus Strix are the wood owls. They are medium to large owls, having a large, rounded head and no ear-tufts. The comparatively large eyes range from yellow through to dark brown. Colouring is generally designed fro camouflage in woodland, and a number of the member of this genus have colour phases. There are 20 species scattered practically throughout the globe with the exception of Australasia, the South Pacific and Madagascar, where the genus Ninox takes its place. There being no clear generic differences between Strix and Ciccaba genera, and DNA evidence suggesting very close relationships, many authorities now merge the latter into the former.
Physical charateristics
Medium-sized owl with noticeably stocky body, large and round head. 35-39 cm, 440-550 g, wingspan 95-104 cm.
Plumage polymorphic, with intermediates. Nominate race mostly grey-brown, facial disc generally pale with some darker concentric rings, crown with dark center bordered by pale bands.
Upperparts heavily mottled brown with darker shaft streaks outer webs of outer scapulars and upperwing coverts with large white or cream spot at tip. Underparts striaked dark and with variable thin cross-bars. Iris blackish-brown. Bill horn-clored to pale yellowish. Toes grey.
Plumage polymorphic, with intermediates. Nominate race mostly grey-brown, facial disc generally pale with some darker concentric rings, crown with dark center bordered by pale bands.
Upperparts heavily mottled brown with darker shaft streaks outer webs of outer scapulars and upperwing coverts with large white or cream spot at tip. Underparts striaked dark and with variable thin cross-bars. Iris blackish-brown. Bill horn-clored to pale yellowish. Toes grey.
Listen to the sound of Tawny Owl
[audio:http://www.planetofbirds.com/MASTER/STRIGIFORMES/Strigidae/sounds/Tawny Owl.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 81 | cm | wingspan max.: | 96 | cm |
| size min.: | 37 | cm | size max.: | 43 | cm |
| incubation min.: | 28 | days | incubation max.: | 30 | days |
| fledging min.: | 32 | days | fledging max.: | 30 | days |
| broods: | 1 | eggs min.: | 2 | ||
| eggs max.: | 6 |
Range
Eurasia : West Eurasia, North Africa. The East-West limits of the Tawny Owl are Britain and Korea; the North-South limits Fennoscandia/Russia and the wooded parts of North Africa and the Caucasus.
Habitat
Open forest, woodland, farmland with trees, parks, larger gardens, also rocky areas with sufficient tree and bush cover.
Avoids large unbroken forest tracts, wetlands and treeless plains, frosty or arid climates.
Occurs from fringe of boreal zone through temperate regions and steppe to Mediterranean and related mountain zones. For hunting, requires richly structured habitat with plenty of lookout posts, including sparse woodland, clearings, and gardens among mature trees.
Avoids large unbroken forest tracts, wetlands and treeless plains, frosty or arid climates.
Occurs from fringe of boreal zone through temperate regions and steppe to Mediterranean and related mountain zones. For hunting, requires richly structured habitat with plenty of lookout posts, including sparse woodland, clearings, and gardens among mature trees.
Reproduction
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. 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.
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. 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.
Feeding habits
Small mammals, like shrews and rodents up to young rabbits, small birds including pigeon. Also amphibians, reptiles, insects, and occasionally fish. Relative proportions of prey taken considered to reflect availability, rather than food specialization. Chiefly nocturnal, hunting between dusk and dawn. Occasionally diurnal. Most prey located by sound. Hunts mostly from perch, turning body occasionally, makes frequent short flights, returning to same perch. Glides or drops on to prey, extends wings on impact to cover or strike prey. Usually consumes food on elevated perch.
Video Tawny Owl
httpv://www.youtube.com/watch?v=SQFnPu1pJtg
copyright: Paul C. King
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Strix aluco is a widespread resident across much of Europe, which constitutes >50% of its global range. Its European breeding population is large (>480,000 pairs), and was stable between 1970-1990. Although there were declines in countries such as Croatia and Sweden during 1990-2000, key populations in France, Germany, Poland and Romania were stable, and the species remained stable overall. Up until the early part of this century, The Tawny Owl suffered the same kind of persecution as other raptors – many thousands were shot, trapped and displayed on gamekeepers’ gibbets. This has improved steadily, with the decline of keepering, and changes in land use generally.
Strix aluco is a widespread resident across much of Europe, which constitutes >50% of its global range. Its European breeding population is large (>480,000 pairs), and was stable between 1970-1990. Although there were declines in countries such as Croatia and Sweden during 1990-2000, key populations in France, Germany, Poland and Romania were stable, and the species remained stable overall. Up until the early part of this century, The Tawny Owl suffered the same kind of persecution as other raptors – many thousands were shot, trapped and displayed on gamekeepers’ gibbets. This has improved steadily, with the decline of keepering, and changes in land use generally.
Migration
Mainly resident. Breeding adults sedentary, remaining in territory all year. Juveniles have protracted period of 2–3 months under parental care, and disperse in period August-November; mortality highest then, for those not replacing dead adults usually starve rapidly. Dispersal complete by late autumn, juveniles by then either dead or established in territory; very little subsequent movement, and then usually under stress of cold winter weather in northern parts of range.
Distribution map
Literature
Title Possible first record of double brooding in the tawny owl Strix aluco
Author(s): Iigo Zuberogoitia, Jose Antonio Martnez, Agurtzane Ir ta, Ainara Azkona & Iaki Castillo
Abstract: […].A Tawny Owl population in Bizkaia was monito..[more]..
Source: Ardeola 51(2), 2004, 437-439
Title Tawny Owl’s territory occupancy in Eastern Latvia.
Author(s): Avotins, A
Abstract: The Tawny Owl’s territory occupancy was studied on..[more]..
Source: Bird Census News 13 (2000):167-173
Title Wood quality and the Tawny Owl Strix aluco in different forest
types of central Italy
types of central Italy
Author(s): Luca Salvati, Alberto Manganar & Lamberto Ranazzi
Abstract: We correlated breeding density and proportion of w..[more]..
Source: ORNIS SVECICA 12:47-51, 2002
Title Wood quality and the Tawny Owl Strix aluco in different forest
types of central Italy
types of central Italy
Author(s): Luca Salvati, Alberto Manganar & Lamberto Ranazzi
Abstract: The population of Tawny Owls Strix aluco breeding ..[more]..
Source: ORNIS SVECICA 12:63-67, 2002
Title Analysis of genetic parentage in the tawny owl ( Strix aluco ) reveals extra-pair paternity is low
Author(s): Verena Saladin, Mathias Ritschard et al.
Abstract: We have investigated genetic parentage in a Swiss ..[more]..
Source: J Ornithol (2007) 148:113-116
Title Living at the limit: Ecology and behaviour of Tawny Owls Strix aluco in a northern edge population in central Norway.
Author(s): Sunde P., Overskaug K., Bolstad J.P. & Oien IJ.
Abstract: The Tawny Owl Strix aluco was studied at the north..[more]..
Source: ARDEA 89 (3): 495-508.
Title Breeding of the tawny owl Strix aluco in Finland: responses of a southern colonist to the highly variable environment of the north
Author(s): T. Solonen
Abstract: Large-scale patterns and variations in the occurre..[more]..
Source: Ornis Fennica 82:97-106. 2005