Eurasian Eagle-Owl (Bubo bubo)

Eurasian Eagle-Owl

[order] STRIGIFORMES | [family] Strigidae | [latin] Bubo bubo | [authority] Linnaeus, 1758 | [UK] Eurasian Eagle-Owl | [FR] Grand duc d’Eurasie | [DE] Uhu | [ES] Buho Real | [NL] Oehoe

Subspecies

Monotypic species

Genus

Members of the genus Bubo are the largest of the owls. Heavily built with powerful talons they are recognisable by their size, their prominent ear-tufts, and their eyes that vary in colour from yellow to brown but are frequently vivid orange. The genus, including the Asian fish owls of the genus Ketupa – now believed to be part of Bubo – comprises of 20 species ranging Eurasia, Indonesia, Africa and the Americas. DNA evidence suggests that the Snowy Owls of Nyctea and the fish owls of Scotopelia are also candidates for inclusion in this genus.

Physical charateristics

The largest owl in the region, with long, broad wings, and pronounced ear-tufts. Almost barrel-shaped, powerful bill and feet. flight recalls that of a buzzard.
Nominate with buffy grey-brown facial disc with indistinct dark border, light buff eyebrows. Hindneck light buff-brown, mantle blacker, rest of upperparts warm buff-brown, all heavily streaked blackish. Flight-feathers barred buffish and dark brown, throat whitish, rest of underparts brownish orange-buff, paler on belly with long black droplets on chest.

Listen to the sound of Eurasian Eagle-Owl

[audio:http://www.planetofbirds.com/MASTER/STRIGIFORMES/Strigidae/sounds/Eurasian Eagle-Owl.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 138 cm wingspan max.: 170 cm
size min.: 59 cm size max.: 73 cm
incubation min.: 34 days incubation max.: 36 days
fledging min.: 50 days fledging max.: 36 days
broods: 1   eggs min.: 2  
      eggs max.: 5  

Range

Eurasia : widespread

Habitat

Mainly rocky country with cliffs and ravines, caves, patches of woodland, scattered trees of groves, generally in undisturbed wilderness areas, also open forest, taiga and other types of woodland.
Forages also over open or sparsely wooded terrain, as well as floodland, heaths, farmed valley bottoms or levels with grassland, small arable fields, and even refuse dumps

Reproduction

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. Often several potential nest 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. The eggs 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.

Feeding habits

Diet mostly mammals, from size of water vole to adult hares, and birds from size of jay to herons and buzzard, also occasionally amphibians, reptiles, fish, and invertebrates.
Primarily nocturnal, somewhat crepuscular, even diurnal in summer at N edge of range, Hunts mostly from open perch, also in searching flight.
Takes prey by surprise while flying close to ground or tree-tops. Sometimes makes systematic searches of rock crevices for roosting birds. Said also to take birds in full flight, to seize fish by plunging into water like Osprey.

Video Eurasian Eagle-Owl

httpv://www.youtube.com/watch?v=ZVZ4nBqKTNg

copyright: youtube


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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very 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.
Bubo bubo is a widespread but patchily distributed resident across much of Europe,
which accounts for less than a quarter of its global range. Its European breeding
population is relatively small (<38,000 pairs), and underwent a large decline during 1970-1990. Although there were declines in a few countries during 1990-2000, the species increased or was stable across most of its European range, and was stable overall. Nevertheless, its total population size probably still remains below the level that preceded its decline, and consequently it is provisionally evaluated as Depleted.
This largely sedentary owl has a wide distribution in northern and Africa Eurasia, from Portugal to China and between 16 degrees N and 68 degrees N. It exists in most of the countries of the European Union, except in the British Isles. Its populations have considerably declined since the beginning of the century following heavy persecution and locally also following a myxomatosis epidemic which destroyed rabbit populations. The species had consequently disappeared from many regions. Since 1970 a definite recovery has been noticed, regarding the numbers and the distribution as well. The species is again breeding in the Netherlands, Belgium and Luxembourg. This recovery has been assisted by reintroduction programs. In the Mediterranean regions the decline is still in progress. The total population of the European Union is estimated at 2000-2500 breeding pairs
Eurasian Eagle-Owl status Least Concern

Migration

Resident in the whole of its breeding range. Allthough Northern birds migrate South where temparetureis low or food becomes scare

Distribution map

Eurasian Eagle-Owl distribution range map

Literature

Title Reproductive success of a reintroduced population of Eagle Owls Bubo bubo in relation to habitat characteristics in the Eifel, Germany
Author(s): Dalbeck L. & Heg D. 2006
Abstract: Eagle Owls Bubo bubo were successfully reintroduce..[more]..
Source: Ardea 94(1): 3-21

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Title Development of chicks and predispersal behaviour of young in the Eagle Owl Bubo bubo
Author(s): V. PENTERIANI, M. M. DELGADO, C. MAGGIO, A. ARADIS & F. SERGIO
Abstract: Little quantitative information on the development..[more]..
Source: Ibis 147 (1), 155-168

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Title First record of cooperative nesting in the Eagle Owl Bubo bubo
Author(s): Jos Enrique MARTNEZ, Francisco GIL, Iigo ZUBEROGOITIA, Jos Antonio MARTNEZ and Jos F. CALVO
Abstract: Monogamy appears to be the most common
mating sys..[more]..
Source: Ardeola, 52(2), December 2005, 351-353

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Title Use of farm chicken carcasses by the Eagle Owl Bubo bubo
Author(s): Serrano, D.
Abstract: The diet of the Eagle Owl Bubo bubo has been widel..[more]..
Source: Ardeola 47(1), 2000, 101-103

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Title Factors affecting the vocal behaviour of Eagle Owls Bubo bubo: effects of sex and territorial status
Author(s): Martnez, J. A. & Zuberogoitia, I.
Abstract: We performed a playback experiment in order to ass..[more]..
Source: Ardeola 49(1), 2002, 1-9

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Title Possible first record of multiple brooding of the Eagle Owl Bubo bubo
Author(s): Martnez, J. A., Martnez, J. E., Prez, E., Zuberogiotia, I. & Izquierdo, A.
Abstract: […]. Since 1989, we have monitored the Eagle Owl..[more]..
Source: Ardeola 50(1), 2003, 77-79

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Title Habitat preference models for nesting Eagle Owls Bubo bubo: How much can be inferred from changes with spatial scale?
Author(s): Joaqun Ortego & Mario Daz
Abstract: Aims: To analyze whether habitat preference patter..[more]..
Source: Ardeola 51(2), 2004, 385-394

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Title Eagle Owl Bubo bubo proximity can lower productivity of cliff-nesting Peregrines Falco peregrinus
Author(s): Mattia Brambilla, Diego Rubolini & Franca Guidali
Abstract: The Eagle Owl Bubo bubo is conventionally regarded..[more]..
Source: Ornis Fennica 83:20-26. 2006

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Title Effects of landscape spatial structure and composition on the settlement of the Eagle Owl Bubo bubo in a Mediterranean habitat
Author(s): Penteriani V., Gallardo M., Roche P. & Cazassus H.
Abstract: We analysed the breeding density of a Mediterranea..[more]..
Source: ARDEA 89 (2): 331-340

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Title Reproductive success of a reintroduced population of Eagle Owls Bubo bubo in relation to habitat characteristics in the Eifel, Germany.
Author(s): Dalbeck L. & Heg D.
Abstract: Eagle Owls Bubo bubo were successfully reintroduce..[more]..
Source: ARDEA 94 (1): 3-21.

download full text (pdf)

Title Consequences of Eagle Owl nest-site habitat preference for breeding performance and territory stability
Author(s): J. Ortego
Abstract: I tested the hypothesis that nest-site habitat pre..[more]..
Source: Ornis Fennica 84:78-90. 2007

download full text (pdf)

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