The Long-Eared Owl

The Long-Eared Owl– Asio otus


  • Kingdom: Animalia
  • Class: Aves
  • Order: Strigiformes
  • Family: Strigidae
  • Gen: Asio
  • Species: Asio otus

Identification characters

The wood thrush is a species of medium-sized night owl. Body length is 31-37 cm, wingspan is 86- 98 cm and mass is 220-305 grams, which is smaller than the woodcock.

On the dorsal side the plumage is cream-reddish, finely mottled, and on the ventral side it is streaked. On the head there are two long tufts or tufts, visible when the bird is in erect camouflage, during courtship or when alarmed. The tufts are not visible when the bird is relaxed, nor when it is in flight. The eyes are orange. The facial disc is uniform and has two white arches in front of the eyes.
The sexes are similar, the female being slightly larger than the male. The male’s plumage is lighter in colour, with fewer striations on the ventral side, and the face is lighter in colour.

The genus name, ⹂Asio⹂ , comes from Latin for a night bird with ‘ears’. Otus is the Latinized form of the Greek otos, meaning “eared or tufted”. It is therefore a night bird with ‘ears’.

The undigested bones of the rodents it consumes are regurgitated as ingluvium. In the winter, you can see them on the ground in the area where the wintering colony has formed. This species has a record longevity in the wild of 27 years and 9 months.


The thistle is found in the northern hemisphere, with a wide distribution from the Eurasian region to northern Africa. It is also found throughout the North American continent as far north as Mexico.

In Europe, the breeding population is between 304 000-776 000 pairs, representing
28% of the global population Northern populations are migratory and those in the centre of the continent are partly migratory or dispersive. In the north they move up to sub-arctic areas.

In Romania, the woodcock is found throughout the year, both during the nesting season,
and during the cold season, being present in most regions. There are an estimated 11 389 nesting pairs in Romania.
In addition to the resident birds, in winter there are also birds migrating from other parts of the continent.

The European population is between 7 500 000 and 19 000 000 breeding pairs.

In Romania, the population of magpies ranges from 668,969 to 822,706 breeding pairs and is stable.

Living environment and biology of the species

The wood thrush nests in woodlands and semi-open mosaic habitats, near arable land or in abandoned corvid nests along tree and shrub lines, in parks or plantations, in old orchards, tree and shrub cemeteries, in various wooded areas in or near localities.

In Romania it is widespread in wooded and semi-wooded habitats throughout the country,
from lowland and lowland areas to the high hills.

It nests in the nests of crows, coots and other corvids. In winter it gathers in groups of several dozen or more.
During the day it hides in the trees, and in the evening and at night it hunts in the fields around villages, where it captures field mice or other small mammals, small birds or even insects. Prey is located mainly by sound. It hunts by silently flying slightly above the ground, suddenly swooping down on prey. Sometimes it also hunts by lying in wait on various supports.
It is a monogamous species. It exhibits territorial behaviour, but pairs can often be located quite close together, 50-150 m apart. The male marks its territory with wingbeats that sound like small clicks, but also with vocal emissions. It nests in forest patches in old nests of other species such as crows, coots, other corvids, less often on the ground at the base of trunks or in tall grass. Feeds mostly on mice, the rest of the food is provided by small birds. It is a nocturnal arboreal bird. It does not hunt by day, usually sitting near the trunk of a tree.

In Romania, the wood thrush is often heard breeding on the outskirts of villages or on tree or bush lines.
In winter, several dozen or hundreds of individuals congregate in sheltered, windless places with rich vegetation, usually in tuia or other ornamental conifers in front of buildings, schools, kindergartens or even in people’s yards. At the base of the trees that shelter the thickets, large numbers of English conifers can be seen.
It lays 4-6 eggs at two-day intervals from mid-March, sometimes even earlier, until early April. Eggs are white. elliptical, smooth, with fine pores. The female broods for 27-32 days, during which time she is fed by the male. The chicks are nestlings and are fed by the female on food brought by the male. The chicks leave the nest after about 21 days but remain in the vegetation in the nest area and are fed by the adults. They become capable of flight at about 35 days. Under abundant feeding conditions, the female may also lay her second clutch.


It is a monogamous species. The nest is built by both partners in 5-6 weeks. It consists of an earthen cup lined with roots, grass and hairs, held in a structure made of branches. The nest usually has two entrances. It is positioned in a tree or bush, a few feet off the ground. The female lays 4-9 grey-green eggs with brownish spots. Incubation is carried out by the female and lasts 16-21 days, during which time the female is fed by the male. Both parents feed the young, but it is the male that guards the nest. Juveniles fly from the nest after 25-29 days, but the family stays together until autumn.

Threats and conservation measures

The main threat to the woodland bulrush is related to the degradation and loss of suitable habitat, breeding areas and agglomeration through deforestation of trees near agricultural areas and wetlands with land use change. Other threats are the intensive use of pesticides in agriculture, the use of poisons against rodents, leading to the depletion of the main food source, and poaching.

The main conservation measures are: maintaining, creating and promoting uncultivated land with appropriate vegetation, maintaining and prohibiting the burning of stubble, maintaining and emphasising corridors between areas of spontaneous grassland including trees, maintaining appropriate stubble management in areas where it has traditionally been carried out, reducing the use of chemicals in agriculture, applying low toxic and persistent chemicals. In areas where the species is crowded, measures should be taken to ensure quietness. Hunting legislation must be respected, with anti-poaching measures enforced through cooperation between environmental protection organisations, hunting organisations, the gendarmerie and the Environmental Guard. The management of telecommunication or power cables and the laying of new cables to national standards guarantees bird safety.

It is also recommended to identify and manage areas of increased mortality caused by roads, inventory breeding areas, both actual and potential, identify migration, feeding and agglomeration areas important for conservation, promote studies on various aspects of the biology of the species.


For conservation purposes it is recommended to maintain and enhance corridors between areas of spontaneous grassland including scattered trees, tree lines and groups of non-productive trees, to maintain stubble fields and prohibit their burning, to reduce chemicals used in agriculture, to apply less toxic and persistent chemicals, to avoid the use of herbicides during critical periods such as breeding periods. In open agricultural areas it is good to maintain a mosaic of habitats with tree and shrub patches. Illegal bush fires should be prevented and, if committed, penalised. Importance should be attached to maintaining critical breeding areas, controlling and penalising nest destruction, and hunting should be limited.

Studies on various aspects of the species’ biology, especially those concerning demographic parameters, inventorying current and potential breeding areas and identifying important areas for the conservation of the species are useful and should be promoted.


      • Lars Svensson, Hakan Delin, 1988, Photographic guide to the birds of Britain and Europe, Owls, 164, Chancellor Press, London
      • Svensson (text and maps), 2017, Guide to bird identification. Europe and the Mediterranean area, translation and adaptation in Romanian: Romanian Ornithological Society, Emanuel Ștefan Baltag, Sebastian Bugariu, Alida Barbu, p.228;Radu Dimitrie, 1983, Mic atlas ornitologic, Edit. Ciprian Fountain, Kovács Istvan, Benkő Zoltán, Daròczi Szilárd, Domșa Cristian, Veres-Szászka Judit (editors), 2022, Atlas of bird species of community interest in Romania, 2nd edition – Love birds, save nature!, Project financed by the European Regional Development Fund through the Large Infrastructure Operational Programme 2014-2020, Ministry of Environment, Water and Forests – Biodiversity Directorate, scientific coordination Romanian Ornithological Society and Association for the Protection of Birds and Nature Milvus Group, produced by EXCLUS PROD SRL, p. 306-307 ;
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