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

Eurasian Eagle-Owl determination

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.

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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.

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

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.

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

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.

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

Range: Eurasia : widespread