Eurasian Eagle-Owl - Description

Description

The Eagle Owl is a very large and powerful bird, smaller than the Golden Eagle (Aquila chrysaetos) but larger than the Snowy Owl. It is sometimes referred to as the world's largest owl, although Blakiston's Fish Owl (B. blakistoni) is slightly heavier on average and the Great Grey Owl (Strix nebulosa) is slightly longer on average. The Eagle Owl has a wingspan of 160–188 cm (63–74 in), with the largest specimens attaining 200 cm (79 in). The total length of the species can range from 56 to 75 cm (22 to 30 in). Females weigh 1.75–4.2 kg (3.9–9.3 lb) and males weigh 1.5–3 kg (3.3–6.6 lb). In comparison, the Barn Owl (Tyto alba), the world's most widely-distributed owl species, weighs about 500 grams (1.1 lbs) and the Great Horned Owl (B. virginianus), which fills the Eagle Owl's ecological niche in North America, weighs around 1.4 kg (3.1 lbs). Among standard measurements, the tail measures 23–31 cm (9.1–12 in) long, the tarsus measures 7.4–8.8 cm (2.9–3.5 in) and the bill is 4.2–5.8 cm (1.7–2.3 in).

Based on the wing chord length (the only measurement taken for the many of the less studied subspecies), there is considerable variation across the races, with owls at higher altitudes and more Northern latitudes being the larger varieties. The smallest race is B. b. nikolskii, found in warm, rocky desert-like habitats from eastern Iraq and Iran to Pakistan and Afghanistan and measuring 37.8–46 cm (14.9–18 in) in wing chord length. The largest race is B. b. yenisseenis of the icy forests of central Siberia to northern Mongolia at 44.3–51.8 cm (17.4–20.4 in). Many subspecies still require detailed description and study. Two owls formerly considered subspecies of the Eurasian Eagle Owl are now recognized as distinct species: the Pharaoh Eagle-Owl (B. ascalaphus) and the Rock Eagle Owl (B. bengalensis).

The great size, bulky, barrel-shaped build, ear tufts and orange eyes make this a distinctive species. The ear tufts of males are more upright than those of females. The plumage coloration, across 13 accepted subspecies, however can be somewhat variable. The upperparts may brown-black to tawny-buff to pale creamy gray, typically showing as dense freckling on the forehead and crown, stripes on the nape, sides and back of the neck, and dark splotches on the pale ground colour of the back, mantle and scapulars. A narrow buff band, freckled with brown or buff, often runs up from the base of the bill, above the inner part of the eye and along the inner edge of the black-brown ear tufts. The rump and upper tail-coverts are delicately patterned with dark vermiculations and fine wavy barring. The facial disc is tawny-buff, speckled with black-brown, so densely on the outer edge of the disc as to form a "frame" around the face. The chin and throat are white continuing down the center of the upper breast. The whole of the underparts except for chin, throat and centre of upper breast is covered with fine dark wavy barring, on a tawny-buff ground colour. Legs and feet (which are feathered almost to the talons) are likewise marked on a buff ground colour but more faintly. The tail is tawny-buff, mottled dark grey-brown with about six black-brown bars. The bill and feet are black, the iris is orange (yellow in some subspecies).