Eurasian eagle-owl
Even those near the northern limits of their range, where winters are harsh and likely to bear little in food, the eagle-owl does not leave its native range. There are cases from Russia of Eurasian eagle-owls moving south for the winter, as the icebound, infamously harsh climate there is too severe even for these hardy birds and their prey. Similarly, Eurasian eagle-owls living in the Tibetan highlands and Himalayas may in some cases vacate their normal territories when winter hits and move south. Even in those two examples, there is no evidence of consistent, annual migration by Eurasian eagle-owls and the birds may eke out a living on their normal territories even in the sparsest times.
Eurasian eagle-owl
The great size, bulky, barrel-shaped build, erect ear tufts and orange eyes render this as a distinctive species. Other than general morphology, the above features differ markedly from those of two of the next largest subarctic owl species in Europe and western Asia, which are the great grey owl and the greyish to chocolate-brown Ural owl ("Strix uralensis"), both of which have no ear tufts and have a distinctly rounded head, rather than the blocky shape of the eagle-owl’s head. The snowy owl is obviously distinctive from most eagle-owls, but during winter the palest Eurasian eagle-owl race ("B. b. sibiricus") can appear off-white. Nevertheless, the latter is still distinctively an ear-tufted Eurasian eagle-owl and lacks the pure white background colour and variable black spotting of the slightly smaller species (which has relatively tiny, vestigial ear tufts that have only been observed to have flared on rare occasions). The long-eared owl has a somewhat similar plumage to the eagle-owl but is considerably smaller (an average female eagle-owl may be twice as long and ten times heavier than an average long-eared owl).