Friday 9 July 2021

Eurasian Eagle Owl Facts

Extremely variable habitat, from boreal coniferous and mixed deciduous forests to Mediterranean scrub, woody, and grassy steppes; also, rocky and sandy deserts; nests in the Alps up to 2100m (hunting to 2800m), in The Himalayas to 4500m, in Tibetian highlands to 4700m. Palearctic, from continental Europe and Scandinavia east across Russia to C Siberia, Sea of Okhotsk, Sakhalin , and Japan, in the south to the Mediterranean the region, Turkey, N Iraq, Iran, Afghanistan, Pakistan, India, Tibet, China, and Korea.

Plumage considerably darker in humid, oceanic regions than in arid continental areas; size increases from warm regions to cold northern areas or with altitude. Adult (nominate bubo: Europe, south to France, Sicily, Greece, Romania and Ukraine, east to Moscow).

Females, also in flight have the darkest race. Dorsal ground color golden-brown to tawny-buff; crown, mantle, scapular, and underwing-coverts with large black feather tips; hindneck and underparts broadly streaked black (Scandinavian birds are darkest in color). Eyes bright golden-yellow to red-orange; bill greyish-black to black, cere olive-grey; claws black; tarsi and toes densely feathered. Intergrades with slightly smaller and greyer hispanus from the Iberian Peninsula and (formerly) N Africa. Subspecies ruthenus, east of nominate bubo to western Ural river and south to lower Volga basin, and interpositus, south of nominating in Bessarabia, Crimea, Caucasus, Asia Minor, and Iran, are very similar in plumage, slightly greyer or the brown pattern darker, with less or more ochre wash.

Mesoptile (nominate bubo). Down long and soft, scapulars and greater upper wing-coverts like an adult; rusty-buff to dirty cream in color. Eyes pale yellow to pale yellow-orange; cere bluish grey. Juvenile (nominate bubo). Downy, long and soft, pale ochre and dirty cream mesoptile feathers. Eyebrows, the area surrounding eyes, lores and throat white; scapulars, greater upper wing coverts, secondaries and tail feathers like an adult, but narrower, with more pointed tips; primaries invisible or barely visible. Eyes yellow-orange.

Adult (sibiricus: W Siberia and Bashkiria to middle Ob and W Altai, north to limits of the forest). Female, also in flight. Pale ground color mixed cream and off-white or clear white. Crown, hindneck and underparts only narrowly streaked black; limited spots on back, scapular, and upper wing-coverts, indistinctly vermiculated grey, cream or white; belly and flanks finely streaked and vermiculated. Tarsi and toes white. In-flight shows darker upper wing-coverts and dark tips to greater primary coverts. Subspecies yenisseensis of C Siberia has slightly darker plumage, with pale grey and ochre predominating.

Male. Above, much darker and more brownish than yenisseensis; whitish belly more distinctly streaked and barred than sibiricus. 1f Adult (ussuriensis: SE Siberia to NE China, Sakhalin, Hokkaido and S Kuril Islands). Male. Much darker than jakutensis, distinctly darker than sibiricus. Below, more buffish, less whitish, and more streaked and vermiculated. Above, brown markings more extensive and diffuse, white areas are more limited. 1g Adult (kiautschensis: W, C and SE China, E Korea).

Female. Smaller, much darker, tawnier and more rufous than ussuriensis. Plumage duller than in nominating bubo; upperparts paler, more mottled, less heavily marked with brown; below, more ochre and less heavily streaked. Adult (turcomanus: Steppe between Volga and Ural River, east to Transbaikalia). Very pale and yellow race, resembling nikolskii and omissus, with paler streaking and vermiculations, with brown pattern less contrasting.

Adult (hemachalana: Tien Shan and Fergana to Pamir Mountains, north to Kara Tau, south to Baluchistan and Himalayas). Male. A pale and distinctly brown race, similar to swinhoei of S China and to the specifically distinct Rock Eagle Owl Adult (omissus: Turkmenia and adjacent Iran, Chinese Turkestan; intergrades with turcomanus and hemachalana). Male. Typical dessert form. Pale ochre ground color, less rusty than nikolskii; dark markings only slightly developed above and below.


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